Part I. 1985 Florida petroleum production and exploration ( FGS: Information circular 104 )

STATE OF FLORIDA
DEPARTMENT OF NATURAL RESOURCES
Elton J. Gissendanner, Executive Director

DIVISION OF RESOURCE MANAGEMENT
Art Wilde, Director

BUREAU OF GEOLOGY
Walter Schmidt, Chief

INFORMATION CIRCULAR NO. 104

PART I 1985 FLORIDA PETROLEUM
PRODUCTION AND EXPLORATION

By
Jacqueline M. Lloyd
and
Albert V. Applegate

PART II THE BROWN DOLOMITE ZONE OF THE LEHIGH ACRES
FORMATION (APTIAN) IN THE SOUTH FLORIDA BASIN -
A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE
By

Albert V. Applegate

Tallahassee
1987

DEPARTMENT
OF
NATURAL RESOURCES

BOB MARTINEZ
Governor

GEORGE FIRESTONE
Secretary of State

BILL GUNTER
State Treasurer

BETTY CASTOR
Commissioner of Education

BOB BUTTERWORTH
Attorney General

GERALD LEWIS
State Comptroller

DOYLE CONNER
Commissioner of Agriculture

ELTON J. GISSENDANNER
Executive Director

LETTER OF TRANSMITTAL

BUREAU OF GEOLOGY
TALLAHASSEE

Governor Bob Martinez, Chairman
Florida Department of Natural Resources
Tallahassee, Florida 32301

Dear Governor Martinez:
The Florida Geological Survey, Bureau of Geology, Division of
Resource Management, Department of Natural Resources, is publishing
a two-part report as its Information Circular 104. Part I "1985 Florida
Petroleum Production and Exploration" discusses 1985 oil and gas
production, onshore and offshore exploration, and oil production and
exploration statistics. This information is useful to the oil and gas
industry and to the state in planning wise development of Florida's oil
and gas resources.

Part II of this report -- "The Brown Dolomite Zone of the Lehigh Acres
Formation (Aptian) in the south Florida Basin a potentially prolific
producing horizon offshore" discusses the known extent of the Brown
Dolomite Zone in the south Florida Basin and its possible future poten-
tial for producing oil. This information will be useful in planning future
exploration programs and assessment thereof by the State of Florida.

Respectfully yours,

Walter Schmidt, Chief
Bureau of Geology

iii

Printed for the

Florida Geological Survey

Tallahassee
1987

ISSN No. 0085-0616

Iv

CONTENTS

Page

Part I 1985 Florida Petroleum Production and Exploration .... 1

Part II The Brown Dolomite Zone of the Lehigh Acres Formation
(Aptian) in the South Florida Basin-A Potentially Prolific
Producing Horizon Offshore................................ 43

PART I

1985 FLORIDA PETROLEUM PRODUCTION
AND
EXPLORATION

By
Jacqueline M. Lloyd
and
Albert V. Applegate

TABLE OF CONTENTS

Page

Abstract ...................................................... 1
1985 Production ............................................... 2
1985 Driling Activity ......................................... 2
Onshore Exploratory Drilling .............................. 2
Offshore Exploratory Driling .............................. 7
1985 Geophysical Exploration Activity ......................... 9
Recent Florida Oil Field Discoveries ........................... 11
Corkscrew Field ........................................... 11
Discovery ............................................. 11
Sunniland History .................... .............. 16
Wells Drilled Near Corkscrew Field .................... 18
Stratigraphic Cross Section ........................... 18
Conclusion ........................................... 20
Bluff Springs Field ........................................ 20
Discovery .......................................... 20
Historical and Geological Setting .................... 24
Conclusion ........................................... 26
McClellan Field ........................................... 26
Summary ..................................................... 26
References ................................................... 27
Appendices ................................................... 28
I. 1985 and Cumulative Production Data ................. 29

II. 1985 Drilling Activity ..................................... 31
Table I. 1985 Field Wells Drilled ................... 32
Table II. 1985 Wildcat Wells Drilled ................. 34
Table III. Wells Drilled During 1985 in Eastern
Planning Area, Gulf of Mexico............. 36

III. Discovery Well Data ................................ 38

IV. 1985 Geophysical Exploration Activity ................. 40
V. Florida Oil and Gas Geology Related Theses ......... 42

ILLUSTRATIONS
Figure 1. Production decline curve for Florida and for Jay field
1978 through 1985 .............................................. 3

Figure 2. Cumulative oil production through January 1986 for
Florida oil fields ................................................ 4

Figure 3. Stratigraphic nomenclature, Middle Jurassic to Lower
Cretaceous, Florida panhandle ................................. 5

Figure 4. Stratigraphic nomenclature, Upper Jurassic to Lower
Cretaceous, south Florida ...................................... 6

Figure 5. Leases and wells drilled in federal waters, offshore
Florida ....................................................... 8

Figure 6. 1985 geophysical exploration activity ................. 10

Figure 7. South Florida oil field location map .................. 12

Figure 8. Well location map with Sunniland structure, Corkscrew
field ........................................................... 13

Figure 9. Good porosity map of the Sunniland Formation ........ 14

Figure 10. Isopach of Sunniland dark carbonate ................ 15

Figure 11. Log information, P-314 (Sunoco Felda field; Sun Oil
Co. Red Cattle No. 30-1) ...................................... 17

Figure 12. Stratigraphic cross section of Lake Trafford and Sun-
nilard formations ............................................. 19

Figure 13. North Florida oil field location map .................. 21

Figure 14. Well location map with regional Smackover structure,
Bluff Springs field area ........................................ 22

Figure 15. Log information, P-1136 (first offset, dry hole) and
P-1125 (Bluff Springs discovery well) .......................... 23

TABLES

Table 1. Production statistics, Bluff Springs field
discovery well .............................................. 25

1985 FLORIDA PETROLEUM
PRODUCTION AND EXPLORATION

By

Jacqueline M. Lloyd
and
Albert V. Applegate

ABSTRACT

Florida petroleum production declined during 1985, as production
from Jay field continued to decline. Onshore drilling activity main-
tained a level similar to that of 1984, while drilling in federal waters off
Florida showed an increase, with six wells completed during 1985.
This peak in offshore drilling activity was presumably due to the fact
that many offshore leases were close to expiration. Geophysical ex-
ploration activity also increased during 1985, including new ex-
ploration interest in the Apalachicola Embayment area and
significantly increased exploration interest in south Florida.
Wildcat drilling during 1985 yielded one success in south Florida
with the discovery of Corkscrew field. The field is on the Sunniland
trend and produces from the Lower Cretaceous Sunniland Limestone.
Bluff Springs field in north Florida was actually discovered in 1984 but
was not released from confidential status until December 1985. Pro-
duction is from the Jurassic-age Smackover Formation. Drilling began
in December, 1985, for another north Florida discovery, McClellan
field. This field is located in Santa Rosa County and also produces
from the Smackover Formation. The discovery well was completed on
February 28, 1986, and is still confidential with the exception of a
minimum of information released in F &A Oil Reports (April, 1986).
Appendices of oil and gas information are presented. These include
1985 drilling activity, 1985 and cumulative production data, discovery
well date, and 1985 geophysical exploration activity. In addition, a
table listing theses held by the Florida Geological Survey library that
are related to Florida oil and gas geology is presented. This should be
of particular interest to those who are researching Florida oil and gas
for academic as well as exploratory purposes.

1985 PRODUCTION

Florida oil production continued to decline in 1985 (figure 1 and
Appendix 1). During 1985, Florida produced 11,457,913 barrels of oil
compared to 14,461,969 barrels for 1984. This represents a 21 percent
decrease in production. This is a lower percentage than the corres-
ponding decrease for 1983 to 1984 (26 percent, Applegate and Lloyd,
1985).
Figure 1 also illustrates the production decline for Jay field, indi-
cating Jay Field's dominance in Florida oil performance. Smaller field
discoveries continue to keep state-wide decline at a slightly lower rate
than the Jay field decline; however, with Jay field accounting for 71
percent of the state's cumulative production through January 1986
(figure 2), only a discovery of a relatively large field would reverse the
trend.

1985 DRILLING ACTIVITY
Onshore Exploratory Drilling
Thirteen wildcat wells were drilled in Florida in 1985. Six of these
wetls were Smackover-Norphlet tests (stratigraphic nomenclature
shown on figure 3) in Santa Rosa and Escambia counties in west
Florida; all were dry holes. Five wildcat wells were Sunniland tests
(stratigraphic nomenclature shown on figure 4) drilled in Collier and
Lee counties on the Sunniland trend. Four of these wells were dry
holes, but R.K. Petroleum discovered the Corkscrew field in Collier
County. This may well be the best field found in Florida since Exxon's
Raccoon Point field was discovered in 1978. R.K. Petroleum has kindly
waived the confidential status on this well and the Corkscrew field is
discussed separately.
Palmer Petroleum drilled a Paleozoic wildcat in north Florida on
acreage leased by Star Petroleum. Star was one of the large lease-
holders who assembled acreage in Madison, Taylor, Lafayette,
Suwannee, and surrounding counties in the late 1970's. The well
(Florida permit #1181), located in Section 2, T4S, R12E, in Suwannee
County was drilled to a total depth of 6,888 feet and abandoned
without testing.
This is the sixth wildcat drilled to test the Paleozic section in north
Florida since 1980. No shows have been found; as a result, much of the
acreage acquired has been dropped. At present there are no out-
standing drilling permits. Roy Roundtree (Star geologist, personal
communication, 1985) stated that Star would probably keep its
acreage position, but that it was extremely doubtful that any further
drilling would be done until oil prices rebound.
The Sabine Corporation drilled the Miccosukee No. 32-1 (Florida
permit #1169) in Section 32, T49S, R35E in Broward County. This was
the first oil well drilled in Broward County and was abandoned June
28, 1985, at a depth of 11,604 feet. The well was a Sunniland test well
but was located approximately 10 miles to the east of the present
producing trend.

1985 PRODUCTION

Florida oil production continued to decline in 1985 (figure 1 and
Appendix 1). During 1985, Florida produced 11,457,913 barrels of oil
compared to 14,461,969 barrels for 1984. This represents a 21 percent
decrease in production. This is a lower percentage than the corres-
ponding decrease for 1983 to 1984 (26 percent, Applegate and Lloyd,
1985).
Figure 1 also illustrates the production decline for Jay field, indi-
cating Jay Field's dominance in Florida oil performance. Smaller field
discoveries continue to keep state-wide decline at a slightly lower rate
than the Jay field decline; however, with Jay field accounting for 71
percent of the state's cumulative production through January 1986
(figure 2), only a discovery of a relatively large field would reverse the
trend.

1985 DRILLING ACTIVITY
Onshore Exploratory Drilling
Thirteen wildcat wells were drilled in Florida in 1985. Six of these
wetls were Smackover-Norphlet tests (stratigraphic nomenclature
shown on figure 3) in Santa Rosa and Escambia counties in west
Florida; all were dry holes. Five wildcat wells were Sunniland tests
(stratigraphic nomenclature shown on figure 4) drilled in Collier and
Lee counties on the Sunniland trend. Four of these wells were dry
holes, but R.K. Petroleum discovered the Corkscrew field in Collier
County. This may well be the best field found in Florida since Exxon's
Raccoon Point field was discovered in 1978. R.K. Petroleum has kindly
waived the confidential status on this well and the Corkscrew field is
discussed separately.
Palmer Petroleum drilled a Paleozoic wildcat in north Florida on
acreage leased by Star Petroleum. Star was one of the large lease-
holders who assembled acreage in Madison, Taylor, Lafayette,
Suwannee, and surrounding counties in the late 1970's. The well
(Florida permit #1181), located in Section 2, T4S, R12E, in Suwannee
County was drilled to a total depth of 6,888 feet and abandoned
without testing.
This is the sixth wildcat drilled to test the Paleozic section in north
Florida since 1980. No shows have been found; as a result, much of the
acreage acquired has been dropped. At present there are no out-
standing drilling permits. Roy Roundtree (Star geologist, personal
communication, 1985) stated that Star would probably keep its
acreage position, but that it was extremely doubtful that any further
drilling would be done until oil prices rebound.
The Sabine Corporation drilled the Miccosukee No. 32-1 (Florida
permit #1169) in Section 32, T49S, R35E in Broward County. This was
the first oil well drilled in Broward County and was abandoned June
28, 1985, at a depth of 11,604 feet. The well was a Sunniland test well
but was located approximately 10 miles to the east of the present
producing trend.

OIL PRODUCTION DECLINE
1978 THROUGH 1985

1979 1980 1981 1982 1983 1984

0 JAY FIELD

+ STATEWIDE

Figure 1. Production decline curve for Florida and for Jay field 1978 through 1985

I
L-
w

0
a-
-J
0

J
a-

_1

1978

1985

CUMULATIVE. PRODUCTION

THROUGH JANUARY, 1086
51 (7.8%)

S2 (3.8%)
52 \\. ) (N3-5) (0.9%)
S3 (2.3%) N 2 (19 .7%)
S4 (1.9%)\
(SS-14) (1.57)

KEY OIL FIELD

NE BlaIkjWk Creek
N3 Nt. Crl1
N4 &"uwatar Creek *
I5 BlIff Springs
B1 WeUt Feld
2e Sumiland
93 Sunoco Felda
94 bar Island
55 Lehigh Park
96 Raccoo Point
87 Nid-Felda
SB Lake Trafford
89 Tomumnd Canal
SIG Smeinole
Si Forty Nil. Bend *
S12 Corkicrme
913 Baxter Island
914 Pepper Hamock

Nl-Nts North Florida Oil N1 (71.1%)
sl-614. South Florida Oil
i Abandoned
Figure 2. Cumulative oil production through January 1986 for Florida oil fields

GROUPS AND
SERIES STAGES FORMATIONS

LOWER
CRETACEOUS

UPPER
JURASSIC

BERRIASIAN

TITHONIAN

COTTON VALLEY
GROUP

UPPER HAYNESVILLE
KIMMERIDGIAN FORMATION

LOWER
KIMMERIDGIAN

OXFORDIAN

BUCKNER MEMBER
(L. HAYNESVILLE)

SMACKOVER
FORMATION

A I NORPHLET
MIDDLE CALLOVIAN FORMATION
JURASSIC BATHONIAN LOUANN SALT

Figure 3. Stratigraphic nomenclature, Middle Jurassic to Lower
Cretaceous, Florida panhandle

GROUPS AND FORMATIONS

It RATTLESNAKE HAMMOCK FORMATION

O LAKE TRAFFORD FORMATION

S SUNNILAND FORMATION

PUNTA GORDA ANHYDRITE
(.

C,
ui Z
Mc 0
S..

w
-j

ABLE MEMBER

TWELVE MILE MEMBER

WEST FELDA SHALE

PUMPKIN BAY FORMATION

BONE ISLAND FORMATION

i-

WOOD RIVER FORMATION

Figure 4. Stratigraphic nomenclature, Upper Jurassic to Lower
Cretaceous, south Florida

------- 0-

OFFSHORE EXPLORATORY DRILLING

Sale Number 94 was held forthe Eastern Gulf of Mexico in December,
1985. Figure 5 shows leases held prior to the bidding and leases
acquired at the sale. It also shows the location of wells drilled in federal
waters offshore Florida during 1985. Appendix II, table III is a review of
the 1985 offshore drilling activity.
Industry paid over $124 million for 82 leases (nine square miles, 5,760
acres per lease) out of total of 2,600tracts available. This marked lack of
interest in the Eastern Gulf of Mexico was not unexpected, and no
resumption of interest in the area is expected in the near future.
Drilling in this area has been disappointing. The Destin Dome, which
was once considered to be very attractive, was originally drilled in 1975.
Over one billion dollars have been spent on leases and drilling and no
appreciable reserves have been found. Sohio is rumored to have spent
in excess of $20 million drilling their Gainesville lease. Drilling in the
Charlotte Harbor area encountered basement at 10,000 to 12,000 feet on
the Sarasota Arch. Drilling in the Pulley Ridge area has been postoned
due to environmental studies, and this area will not be drilled before
late-1986 at the earliest. In the Destin Dome and Pensacola areas, gas
and condensate are the probable hydrocarbons to be encountered.
These commodities are in oversupply at the present time. Forthese and
other reasons, almost 100 blocks in the Eastern Planning Area expired
in 1985 without being drilled.
In sale no. 94, the highest bids went for tracts located on the Destin
Dome. These bids were made by Shell Offshore Inc, and Amoco. Shell
was high overall bidder, spending-$30.6 million for its interest in 30
tracts. Amoco spent $27.8 million forits. interest in 24 tracts. Both of
these companies purchased drilling blocks outside of the Destin Dome
area.
In the Destin Dome and Pensacola areas, the principal drilling targets
are the Norphlet and Smackover formations of Late Jurassic age. The
former is capable of high volume gas production in the Mobile Bay area
about 100 miles to the west, where wildcat and development drilling has
been carried out by several companies since the original discovery by
Mobil in 1979. The Norphlet is as much as 600 feet thick in the Mobile
Bay area; unfortunately, it appears to thin rapidly to the east in Florida
waters. The Smackover Formation is the principal producing formation
in the Jay and Blackjack Creek fields which are approximately 100 miles
to the northwest of the Destin Dome. In other areas in the Eastern
Planning Area, Cretaceous limestones and dolomites are the principal
wildcat targets.
The exploratory drilling which took place offshore in 1985 was not
encouraging. Four Smackover-Norphlet tests were drilled on the Destin
Dome. Two of these unsuccessful wildcats were drilled by Shell in Block
160. Exxon drilled a Smackover-Norphlet dry hole in Block 284. Chev-
ron did likewise in Block 422. It was rumored that Shell's first well in
Block 160 had a good show, but no pipe was run in the well.
In the Gainesville area (figure 5) Sohio is believed to have drilled

Fiaure 5. Leases and wells drilled in federal waters, offshore Florida

through a thick Eagle Mills (Triassic) section before abandoning a well
in Block 707 in Paleozoic rocks at 15,994 feet.
Sohio drilled a wildcat in Pensacola Block 948 to a total depth of
18,958 feet. The well was drilled to test a Louann high and was located
on the down-thrown side (southwest) of a regional fault. A seven-inch
liner was cemented at 18,956 feet and the Smackover and Norphlet
formations were tested. Test data are not available but the well was
abandoned.
Drilling in the offshore during 1986 (through June 1986) in the East-
ern Planning Area of the Gulf of Mexico has been slow. As concessions
granted by the federal government last for only five years without
testing, Shell drilled one wildcat in Block 622 of Charlotte Harbor. This
well was drilled to a total depth of 10,500 feet. Shell also drilled a test
well in Block 512 of the DeSoto Canyon area to a total depth of 12,300
feet. Both wells were abandoned without testing.

1985 GEOPHYSICAL EXPLORATION ACTIVITY

The implementation of Chapter 377, Part 1, Florida Statutes authoriz-
ing the Florida Department of Natural Resources to regulate geophysi-
cal activities (Applegate and Lloyd, 1985), gives the Florida Geological
Survey the opportunity to monitor not only areas of seismic activity in
Florida, but also areas of interest to industry that, for one reason or
another (i.e. economics, permitting problems, logistical problems) were
not surveyed. Thirty-one applications for geophysical permits were
received by the Florida Geological Survey during 1985. Of these 34
applications, 23 have been permitted, fourwerewithdrawn by the appli-
cants, and four are still being processed. The areas covered by these
permits are shown on figure 6. Only 18 permitted areas were actually
surveyed during 1985; four permitted surveys were cancelled and the
remaining one is "on hold" (presumably awaiting changes in economic
conditions).
As was the case in 1984, seismic activity for 1985 was greatest in the
Florida panhandle. However, unlike 1984, panhandle activity was not
strictly concentrated in Escambia and Santa Rosa counties but in-
cluded seismic surveys in Liberty, Franklin, and Wakulla counties.
Applications were also received which included, in addition to those
counties listed above, proposed surveys in Okaloosa, Walton, Bay, and
Calhoun counties. Surveys in these counties were not run, but the
applications indicate an increased interest in Florida panhandle explo-
ration. This apparently increased interest includes the Apalachicola
Embayment area which was discussed by Applegate, et al. (1978) as an
area with significant Smackover oil potential. The panhandle surveys
completed in 1985 yielded 243 miles of shot-hole and 276 miles of
Vibroseis lines, for a total of 519 miles.
Only one application was received during 1985 for geophysical oper-
ations in north peninsular Florida. This application was permitted and
the survey was completed. It included 52 miles of shot-hole lines in
Madison County.

,--wmalw

m-,-,-- O' I
rn.^.-E^

STATE OF FLORIDA
1M3 (iEOCHYWCAL EXP~ORATIN ACrTTY

Figure 6. 1985 geophysical exploration activity

Geophysical exploration activity increased by an order of magnitude
compared to 1984 in south Florida. A total of 392.25 miles (330 miles
Vibroseis; 62.25 miles shot-hole) of seismic surveys were run in south
Florida during 1985, compared to a total of only 22 miles for 1984.
Surveys also covered a broader geographic area, including parts of
Okeechobee, Collier, Hendry, Dade, Palm Beach, and Broward
counties.
1985 seismic activity showed a general increase in exploration in
Florida over more extensive geographic areas. The recent discoveries in
both north (panhandle) and south Florida should encourage the con-
tinuance of this trend.

RECENT FLORIDA OIL FIELD DISCOVERIES

Corkscrew Field

DISCOVERY

The R. K. Petroleum Corp., Midland, Texas, completed 33-2 Rex
Properties, the discovery well of the Corkscrew field on November 10,
1985.-The completion was made in the Sunniland formation of the
Lower Cretaceous. The well is in Section 33, T46S, R28E, about 21/2
miles north and slightly west of the one-well Lake Trafford field in
Collier County (figures 7 and 8). This location is favorable on both the
equivalent good porosity map and the isopach of Sunniland dark car-
bonate (Applegate and Pontigo, 1984, and figures 9 and 10).
The 6,000 acre driling block was assembled by Len W. Sipple, Naples,
Florida, and John C. Sipple, Mobile, Alabama, owners of Southern Oil
Exploration Inc., Mobile. Mike Cheeseman, consulting geologist, Pen-
sacola, Florida, prepared geological and structural interpretations of
the area from subsurface data.
A conventional core was taken in the 11,536-564 feet interval of the
Sunniland with 26.5 feet recovered. In the 11,550.25-559.5 feet interval
(8.75 feet) average porosity was 15.25 percent; permeability, 106.2 milli-
darcies (horizontal); water saturation, 37 percent of pore space; and oil
saturation, 11.96 percent of pore space. The Analytical Logging Co.
described the porous interval as a "fossil hash" of dolomitic limestone.
The bottom 4.5 feet of core was described as an indurated, gray, crystal-
line limestone with no permeability. After logging, 7-inch casing was
cemented at 11,547 feet, and an open hole completion was made in the
11,547-565 feet interval of the Sunniland Formation. Production is from
unit 1 of the Sunniland Formation (figure 11). Units 1 and 2 produce in
the Sunniland field to the southeast (Means, 1977). The Lake Trafford
and Sunniland formations were encountered at 11,398 and 11,537 feet
(E-log depths), respectively.
A nine-hour swab test of the well produced 163.33 barrels of 260
gravity oil (A.P.I. at 60 degrees Fahrenheit) with no water, for a daily rate
of 435 barrels. The well was placed on a pump and has produced about

OIL FIELDS IN SOUTH FLORIDA

Pb TOWNSEND CANAL

LEE CO. .. -u-FELO-
W3ET S3C= FELDA R30E R3 1E
DISCOVERY WELL
P CORKSOCW FIELD

P '-222

HENDRY CO.

PALM BEACH CO.

AIN, 0 SEMINOLE
1% BEAR GAUC T493

PEPPER l:uOCK 0 ATER ISLAND
BROWARD CO.

COLLIER CO.
RACOON POSIT
0 ---

DADE CO.

O FORTY MILE BEND

EXPLANATION
A CTVE OIL FIELD
SMINACTNE OIL FIELD

0 0 .ILES
SCALE

Figure 7. South Florida oil field location map

O NEW PERMITTED LOCATION, P-1201
* OIL FIELDS
P-1107 and P-1199; CORKSCREW
P-401; LAKE TRAFFORD
ABANDONED WILDCATS
(1) P-408 (5) P-853
(2) P-1030 (6) P-849
(3) P-1001 (7) P-477
(4) P-1058

0 2000 4000 86000 8000
FEET
CONTOUR INTERVAL: 20 FT.

Corkscrew and Lake Trafford Fields

Structure Map Top of Sunniland

Figure 8. Well location map with Sunniland structure, Corkscrew
field

14

C A 1R N LOTTI

Lf- I

C OLL ttI

EQUIVALENT GOOD.- POROSITY
SUNNILAND FORMATION

Cl 5 FEET

LA KE

PALM

E ACH

8 R WARD

SA E

to KM
0 so MILKE
SCALE

Figure 9. Good porosity map of the Sunniland Formation

SUNNILAND DARK CARBONATE

PEMMP D rY I A.V. APPLEMTE

Figure 10. Isopach of Sunniland dark carbonate

220 barrels of oil per day, which is the pump capacity, with no water.
Production through February 20, 1986, was 20,231 barrels of oil in 92
days, for an average of 220 barrels per day.
Permits were secured to drill a west offset (P-1199) and a north offset
(P-1201) to this well. The west offset (32-1) was completed as a pro-
ducer with the top of the Sunniland encountered at 11,486 feet
(figure 8).

SUNNILAND HISTORY

Sunniland field was discovered by Humble Oil and Refining Corp.
(now Exxon) in 1943. Corkscrew field is about 11 miles to the northwest
of the Sunniland field. The boulder zone, a cavernous dolostone in
Tertiary age rocks encountered above 4,000 feet in the subsurface of
south Florida, makes seismic interpretation difficult. For this reason,
drilling of this trend has been limited even though many wells have
produced a million or more barrels of oil. The Sunniland field, with a
total of 18 producing wells, has yielded more than 18,300,000 barrels of
oil and is currently producing more than 10,000 barrels/month from six
wells.
J. A. Means (1977) broke the Sunniland Formation into five units
(figure 11). Following the end of the Punta Gorda Anhydrite deposition,
unit 5, the "Rubble Zone," was deposited as the Sunniland sea
advanced. It is a dark brown to dark gray, argillaceous, micritic limes-
tone, which exhibits conchoidal fracturing and normally has a strongly
petroliferous odor on a fresh surface. It is approximately 50 feet thick.
The lower part of unit 4 has been called the "Black Shale." It is a dense
argillaceous limestone about 40 feet thick. Directly above the "Black
Shale" is a light brown, nonporous, miliolid-rich limestone, which is the
upper part of unit 4. Directly above unit 4 are units 1,2, and 3, which are
approximately 100 feet in total thickness, are located on the producing
trend, and are composed of localized buildups of rudistids, algal plates,
gastropods, Foraminifera, and other organic debris into mounds or pods
which formed porous grainstones. Dolomitization of these grainstones
has enhanced their porosity. These grade laterally into nonporous,
miliolid-rich limestones. Mitchell-Tapping's 1984 and 1985 publications
include excellent photographs of these carbonates.
During and after deposition of the Sunniland Formation, the grain-
stones withstood compaction, and the laterally equivalent miliolid-rich
lime muds were compacted (Means, 1977). This process began at the
time of deposition, as the overlying Lake Trafford Formation thins over
Sunniland highs. Additional compaction caused fractures and minor
faulting around the edge of the oil fields. These fractures probably are
responsible for the "Rubble Zone" in the lowermost Sunniland and may
serve as a conduit for oil to migrate from the "Rubble Zone" (unit 5) and
the "Black Shale" (lower part of unit 4) into the porous units 1, 2, and 3.

Sunniland fm.

S.~;

Unit 1

0

Lake Trafford fm.

s o : : i
a, >*

II~I

Figure 11. Log information, P-314 (Sunoco Felda field; Sun Oil Co. Red Cattle No. 30-1)

o" [

1 i t

WELLS DRILLED NEAR CORKSCREW FIELD

Wells drilled near Corkscrew field, which played a significant role in
defining the geology and structure of the field, were the following
(figure 8);
1. P-408 (Mobile Oil Henry Sanders Trustee 35-1). A drill stem test of
the unit 5 "Rubble Zone" between 11,838 and 11,888 feet recovered
1,000 feet of water column, 1,166 feet of oil and gas cut water column.
2. P-1030 (NRM Audubon Society 1-1). Upper and Lower Sunniland
had scattered odors and mineral fluorescence.
3. P-1001 (NRM Alico 31-2). Seventeen feet of good Sunniland "reef"
rock (grainstone) encountered.
4. P-1056 (NRM Alico 31-4). This well tested 16 barrels of oil and 195
barrels of salt water in eight hours, from the Lake Trafford Formation.
Also had good shows of oil in unit 1 of the Sunniland and shows of oil in
fractures in unit 5 "Rubble Zone." The interval from 12,333 to 12,378
feet, units 1 and 2 in a directionally drilled hole, had an average porosity
of 13.89 percent and horizontal permeability of 11.69 md.
5. P-853 (Total Bernice D. Pepper 2804). This well had shows of oil in
the 11,555-560 feet interval of the Sunniland unit 1 with 15 percent
porosity and horizontal permeability ranging from 0 to 67 md. In the
11,594-644 feet interval a core showed good porosity and permeability
development in units 2 and 3, with porosity occasionally above 20
percent. The unit 5 "Rubble Zone" had excellent shows of oil but almost
no porosity or permeability.
6. P-849 (Kanaba Oil and Gas Baron Collier 9-2). This well was drilled
as a step-out to P-401, the discovery well of the Lake Trafford field. Only
scattered porosity and permeability were noted in the upper three Sun-
niland units. Unit 5 had many live shows of oil, but poor porosity and
permeability.
7. P-401 (Mobile Oil Baron Collier 1). This well was the discovery well
of the Lake Trafford field, which produces from the unit 5"Rubble Zone."
The cumulative production through 1985 is more than 253,000 barrels
with daily production of 34 barrels and no water.
8. P-477 (Exchange Oil & Gas Earl Ball 16-1). This is a south offset to
the Lake Trafford discovery well. Completion was made in unit 5. The
well produced about eight barrels per day of oil and was abandoned.

STRATIGRAPHIC CROSS SECTION

A stratigraphic cross section of the Sunniland and Lake Trafford
formations was constructed from P-130 in Collier County to P-152 in
Glades County (figure 12). This cross section was drawn approximately
perpendicular to the producing trend (figures 7, 9, and 10).
In the down-dip well, P-130, relatively thick Sunniland and Lake
Trafford formations are composed principally of dark gray to black,
nonporous limestones and anhydrite. In P-103, which is down-dip from
the producing trend but 18 miles northeast of P-130, the Sunniland

WUo- COiLsiK goop-
ons &I Iwo 9861
PS 1t f Kite
P-.10 (tift IF)
A.

UIou GC CoM0
6t It 1414 R90t

PA9t M14tiflr. W,4ie4fi

SOLOgMlit

0 POtifSli

Hon. -CURRNKy
Se 8 47 t9 K9t
P-,t2 (E9 41r)
+ *

UWit -No. I COwU emr
l1M 41476 KIMF
P*-19i (r ft409
+

CotfAL -1 i gUSt
&so.1 f4AL6 MK
p. II (rOftV Z)

*A AY IAt"OMiy

RAffLS bNAK*
I.IMMOCK

4UkJJILAI D

LUIPUhiA AORDt

OMRAWN ITIVI INCI

Figure 12. Stratigraphic cross section of Lake Trafford and Sunniland formations

20
Formation is composed principally of dark micritic limestone and
anhydrite.
P-222 is on the producing trend; it produced some oil during a drill-
stem test. but was abandoned as noncommercial. The thickening of the
Sunnitand Formation and the thinning of the Lake Trafford Formation
on the producing trend, as well as the development of porosity (an
estimated 19 feet of porosity total) in units 1, 2, and 3 are as expected.
Moving updip to P-133 and P-152, the Sunniland Formation has
thinned to 215 feet and 168 feet, respectively. The porous Sunniland
limestone in P-222 has disappeared, and in its place is chalky, nonper-
meable limestone. The dark micritic limestone has thinned and almost
disappeared in P-152 and is partially replaced by dolomite.

CONCLUSION

Corkscrew field is favorably located on both the good porosity and
the dark carbonate Sunniland Formation maps. The location of the
discovery well was based on geological and structural interpretations of
the area from subsurface data. The discovery is consistent with calcula-
tions made by Applegate and Pontigo (1984). These calculations
showed that 45 barrels of recoverable oil had been found for every foot
of wildcat drilling between 1943 and 1980 In south Florida, and these
reserve figures are very conservative. Additional calculations indicate
that if drilling had been confined to the area of known porosity in the
Sunniland Formation, the figure would have been more than 100 barrels
of oil for every foot of wildcat drilling. These figures indicate that more
drilling should be done in the future in south Florida.

Bluff Springs Field

DISCOVERY

Bluff Springs field, a new oil field In the western panhandle of Florida,
was discovered on March 25,1984. The discovery well, the Stone Petro-
leum Corp. St. Regis Paper Co. No. 29-4 (Florida permit 1125), was
released from confidential status in December, 1985. It was a rank
wildcat located in Section 29, T5N, R31W, Escambia County, approxi-
mately 10 miles west-southwest of Jay field and approximately four
miles southeast of the nearest previously drilled wildcat, Florida permit
1177 (figures 13 and 14). This area, west and southwest of Jay, is known
to be underlain by Louann Salt with seismic studies indicating salt-
induced fault structures in the overlying formations.
Production is from Jurassic-age Smackover Formation dolomites
from 16,332 to 16,339 feet (16,154 to 16,161 feet below MSL, figure 15).
These dolomites are dark brownish-gray to brownish-black, fine
grained micro-crystalline, and show evidence of recrystallization from
originally oolitic and possibly pelletal faces. Examination of core chips
from this interval (at 10x with binocular microscope) reveals primarily
intercrystalline to vuggy porosity. Samples from the top of the produc-

21

NORTH FLORIDA OIL FELD LOCATION MAP

R2 RSW R3w j 1W R wW _29 ja 27W "R6
ST'- COVE. ILL
P-112 McCLELLANM FIELD
DI COVER W
SPBLUFF PRG S WEETWATER tz

--------\ \ i uL^.iACKJACK
C E I isI
.... L__L i_/_ L \ ,

EXPLANATION ,
4 ACTIVE OIL FIELD
4 INACTIVE OIL FIELD
5 0 5 KM
5 0 S MILES
SCALE

Figure 13. North Florida oil field location map

[_ -- -- LEGEND

BLUFF SPRINGS FIELD WELL LOCATION MAP WITH REGIONAL STRUCTURE (TOP OF SMACKOVER) DRY HOLE PLUGGED & ABANDONED
0 PERMIT TED LOCATION

Figure 14. Well location map with regional Smackover structure, Bluff Springs field area

InA AEniA NUTI CChITUhfb

I P-1125

Dual Induction Focusd Log BHC Acoustllog

Compensated Neutron Litho Density

Figure 15. Log information, P-1136 (first offset, dry hole) and P-1125 (Bluff Springs discovery well)

ing zone also appear to have retained some oomoldic porosity,
although the oolites appear to have been replaced with dark brown,
crystalline dolomite. Volumetric calculations based on log analyses by
Dr. Charle H. Tootle of the Florida Bureau of Geology (personal com-
munication, 1985) yielded the following values: pay thickness, 10 feet;
mean porosity, 19.6 percent; mean oil saturation, 88 percent; original oil
in place estimate, 1.3 million barrels; and recoverable oil estimate,
195,067 barrels.
In an initial flowing test (assisted by nitrogen injection) on March 25,
1984, by Stone Petroleum Corp., the well produced 59.6 barrels of oil in
three hours for an approximate daily rate of 477 barrels. Saltwater
production was 170 barrels per day. Oil gravity was 57.0 A.P.I. at 60
degrees Fahrenheit.
The first offset, Florida permit 1136 (the Stone Petroleum Corp. St.
Regis Paper Co. No. 29-3), to the discovery well was also drilled by
Stone Petroleum and is located approximately one-half mile northwest
of the discovery well (figure 14). The Smackover was encountered at
16,342 feet (16,171 feet below MSL), structurally 17 feet lower than in
the discovery well (figure 14). This is apparently too low on the structure
as the well produced only salt water from two thin (three to four-feet
thick) zones within the 16,354 to 16,363-foot interval (16,183-16,192 feet
below MSL) of the upper Smackover. Core analysis by Location Sample
Service, Inc. (LSS, Jackson, Miss.) yielded mean porosity estimates for
these zones of 11.4 and 8.4 percent. Both zones had low permeability.
LSS also found a trace of oil in only one sample from 16,356 feet (16,185
feet below MSL).
On June 14th and 15th, 1985, Hughes Eastern Corp. retested the
discovery well with results similar to those of Stone Petroleum's March
1984 test: 494 barrels of 54.50 A.P.I. gravity oil per day, 238 barrels of
saltwater per day. Ownership of the discovery well was transferred from
Stone Petroleum to Hughes Eastern following this test. Production from
the well began in January, 1986. Monthly production reports for Janu-
ary through June, 1986, indicate that the well Is producing an average of
555 barrels of oil and 221 barrels of water per day (see table 1). Permits
have been issued to Hughes Eastern to drill two offsets, one east and
one southeast of the discovery well (permits 1204 and 1205, figure 14).
Given the results of the offset to the northwest, presumably Hughes
Eastern expects to encounter the Smackover at structurally higher
positions in these new offsets to the east and southeast.

HISTORICAL AND GEOLOGICAL SETTING

The discovery of Bluff Springs field brings the number of oil fields in
north Florida up to five-four active and one plugged and abandoned
(figure 13). The first of the north Florida fields to be discovered was Jay
field in 1970. The discoveries of Mt. Carmel and Blackjack Creek fol-
lowed in 1971 and 1972. Since then, a long series of dry wildcats (84
total) have been drilled in Florida's panhandle. With the exception of the
discovery of the questionably commercial Sweetwater Creek field in

1977, the Bluff Springs discovery represents the first successful wildcat
in west Florida in 12 years. Hopefully, renewed interest and improved
technology will make this only the first in a series of similar successes.

Table I. Production statistics, Bluff Springs field discovery well.

MONTH OIL OIL WATER WATER GAS
(1986) BARRELS BOPD* BARRELS BWPD* MCF
January 18963 612 6466 209 8204
February 11945 427 5061 181 4608
March 17343 559 7110 229 10347
April 18415 614 5770 192 11047
May 18277 609 7311 244 12625
June 15319 511 8104 270 11258
*BOPD: Barrels of oil per day.
*BWPD: Barrels of water per day.

North Florida (i.e. Florida panhandle) oil fields dominate Florida oil
production (Applegate and Lloyd, 1985). These fields account for
approximately 83 percent of the state's cumulative production through
January, 1986 (figure 2). Jay field alone is responsible for 71 percent of
the state's production. In all except Mt. Carmel field, production is from
Jurassic-age Smackover dolomites and limestones (figure 3). Mt. Car-
mel field produces from both the Smackover and the underlying
Jurassic-age Norphlet Sandstone.
Although a mixture of carbonates and clastics can be found within the
Smackover, in the western panhandle producing area it is almost purely
a sequence of dolomites and limestones. The underlying Norphlet
Sandstone is primarily an arkosic sandstone. The Norphlet is underlain
by the Louann Salt which is probably responsible for the structures
found in the north Florida oil fields (except for Sweetwater Creek field
which is believed to be located on a basement high). The Smackover is
overlain by the Buckner Member of the Haynesville Formation. The
Buckner is composed primarily of evaporites and forms the seal for
some of the Smackover producing zones.
Studies of the Jay field Smackover in Florida reveal complex net-
works of producing horizons (Lloyd and Parker, 1985; Lloyd, et al.,
1986). Production is from dolomite horizons found at different levels in
the Smackover; it is also from more than one porosity and facies type.
Production can be from dolomitized oolitic facies with oomoldic poros-
ity. More commonly, it is from dolomitized pelletal facies with intercrys-
talline, vuggy, and leached matrix porosity. Although core chip exami-
nation is not definitive, Bluff Springs field may be producing from both
facies types. Florida's Smackover reservoirs appear to be the result of
the complex interplay of porosity, paleoenvironment, diagenesis (prim-
arily dolomitization), and the formation of networks of producing
horizons.

CONCLUSION

The possible complexity of undiscovered Smackover reservoirs
located in north Florida makes their discovery all the more challenging.
The discovery of Bluff Springs indicates that it can be done. Well
coverage in much of the western Florida panhandle is sparse; there is a
definite need for additional exploration within and adjacent to the
known Smackover producing area in Florida.

McClellan Fleid

Exxon Corp. spudded a rank wildcat (Exxon Corp. State of Florida
33-1, Florida permit #1194) on December 31, 1985, in Section 33, T6N,
R26W, Santa Rosa County (figure 13). This is approximately 3.25 miles
north of the abandoned Sweetwater Creek field and 16 miles east of Mt.
Carmel field which produces from both the Smackover Formation and
the Norphlet Sandstone. The well found 152 barrels of 410 A.P.I. gravity
oil per day from the Smackover through perforations from 14,072 to
14,090 feet (-13,828 to -13,846 feet MSL; F & A Oil Reports, 1986).
Total depth of the discovery is 14,475 feet (-14,231 feet MSL). Two
conventional cores and sidewall samples were taken with no details
released (F & A Oil Reports, 1986). Seven-inch casing was run to 14,473
feet (-14,229 feet MSL) for completion on February 28, 1986 (F & A Oil
Reports, 1986).
The Sweetwater Creek field produced from the Houston Oil and
Minerals Corp., W. M. Stokes 15-2, No. 1 well in Section 15, T5N, R26W,
Santa Rosa County (Florida permit #881). In its initial test the well
produced 624 barrels of 43.50 A.P.I. oil per day and only atrace of water
from a Smackover limestone interval from 14,299 to 14,340 feet (-14,044
to -14,085 feet MSL). Hopes for a significant discovery proved false
when the well began producing 100 percent water in December, 1980.
The field produced a total of 13,695 barrels of oil during its entire
lifetime. In its final year of production (1980) the well produced 1,465
barrels of oil.
SUMMARY

As Florida oil production continues to decline, successful exploration
efforts become more significant. Fortunately, recent oil exploration in
Florida has yielded three new oil fields, two in the western panhandle of
north Florida and one in south Florida. Unfortunately, it would require
the discovery of a great number of such small fields to reverse the
declining production trend which is primarily the result of declining
production at Jay field. Despite this, exploration history indicates that
there is room for additional discoveries within the known Smackover
and Sunniland producing areas. In addition, although efforts have been
unsuccessful to date, the offshore area and the Apalachicola Embay-
ment area are relatively unexplored. The possibility of discovery of a
new "Jay" should not be ruled out. Meanwhile, the chances for smaller
field discoveries have been positively affirmed by recent history.

REFERENCES

Applegate, Albert V., F. A. Pontigo, Jr., and J. H. Rooke, 1978, Jurassic
Smackover oil prospects in the Apalachicola embayment: Oil & Gas
Jour., January 23, 1978, p. 80-84.

Applegate, Albert V. and F. A. Pontigo, Jr., 1984, Stratigraphy and oil
potential of the Lower Cretaceous Sunniland Formation in south Flor-
ida: Fla. Bur. of Geol. Rep. of Invest. No. 89, 40 p.

Applegate, Albert V. and Jacqueline M. Lloyd, 1985, Summary of Florida
petroleum production and exploration, onshore and offshore, through
1984: Fla. Bur. of Geol. Inf. Cir. No. 101, 69 p.

F & A Oil Reports, 1986, Florida, Vol. 13, No. 16, 4-16-86, p. 2.

Lloyd, Jacqueline M. and William C. Parker, 1985, Hydrocarbon reser-
voir formation: Paleoenvironment and structural interrelationship in the
Jurassic Smackover, Jay field, Florida: abstract, Geol. Soc. Amer.
Abstracts with Programs, 98th Annual Meeting, Orlando, Florida, p. 645.

Lloyd, Jacqueline M., Paul C. Ragland, Joan M. Ragland,;and William C.
Parker, 1986, Diagenesis of the Jurassic Smackoiver Formation, Jay
field, Florida: Gulf Coast Assoc. of Geol. Societies Trans., Vol. 36, in
press.

Means, John A., 1977, Southern Florida needs another look: Oil & Gas
Jour., Vol. 75, No. 5, p. 212-225.

Mitchell-Tapping, H. J., 1984, Petrology and depositional environment
of the Sunniland producing fields of south Florida: Gulf Coast Assoc. of
Geol. Societies Trans., Vol. 34, p. 157-173.

Mitchell-Tapping, H. J., 1985, Petrology of the Sunniland, Forty Mile
Bend and Bear Island fields of south Florida: G u If Coast Assoc. of Geol.
Societies Trans., Vol. 35, p. 233-242.

Ottman, R. D., P. L. Keyes, and M. A. Ziegler, 1973, Jay field- a Jurassic
stratigraphic trap: Gulf Coast Assoc. of Geol. Societies Trans., Vol. 23,
p. 146-157.

Sigsby, R. J., 1976, Paleoenvironmental analysis of the Big Escambia
Creek-Jay-Blackjack Creek field area: Gulf Coast Assoc. of Geol.
Societies Trans., Vol. 26, p. 258-278.

28

APPENDIX I

1985 AND CUMULATIVE PRODUCTION DATA

1985 AND CUMULATIVE PRODUCTION DATA-WITH 1984 DATA FOR COMPARISON (1)

-Number of Wells-

-1985 PRODUCTION-

Oil

Gas

CUMULATIVE
PRODUCTION
Water Oil Gas

PRO INJ SI TA TOT (Bbis) (MCF) (Bbis) (MBbls) (MMCF)
NORTHWEST FLORIDA
Bluff Springs 1 0 0 0 1 770 650 600 1 1
Jay 53 28 35 0 116 6358259 9440024 53651208 345740 435776
Blackjack Creek 9 7 8 0 24 1455467 1845391 8691150 51918 47903
Mt. Carmel 1 0 0 0 1 68416 101227 225661 4513 4726
Sweetwater Creek (3) 0 0 0 0 0 0 0 0 14 15
Subtotal 64 35 43 0 142 7882912 11387292 62568619 402186 488421
1984 Subtotal 60 38 44 0 142 11065623 13685980 55132481
SOUTH FLORIDA
Sunoco Felda 10 6 11 0 27 188532 12253 2233681 11107 955
Mid-Felda 2 0 1 0 3 107639 0 234850 933 10
Townsend Canal 4 0 0 0 4 99866 0 255510 225 0
Lehigh Park 4 0 1 0 5 261720 26562 3526210 4536 457
West Felda 28 0 12 3 43 1146947 70630 8156504 38151 3020
Corkscrew 1 0 0 0 1 9472 0 0 9 0
Lake Trafford 1 0 0 0 1 11710 0 0 254 0
Seminole (3) 0 0 0 0 0 0 0 0 85 0
Sunniland 7 0 12 0 19 129841 12300 3162564 18327 1815
Bear Island 16 5 6 0 27 685248 58306 4274921 9201 721
Pepper Hammock 0 0 1 0 1 0 0 0 0 0
Baxter Island (3) 0 0 0 0 0 0 0 0 2 0
Raccoon Point 12 0 1 0 13 934026 109621 638923 1383 152
Forty Mile Bend (3) 0 0 0 0 0 0 0 0 33 2
Subtotal 85 11 45 3 144 3575001 289672 22483163 84246 7132
1984 Subtotal 84 15 37 2 138 3396346 256784 22228837
(Continued on next page.)

FIELD (2)

FIELD (2)

-Number of Wells-
PRO INJ 81 TA TOT

-1985 PRODUCTION-
Oil Gas Water
(Bbis) (MCF) (Bbls)

CUMULATIVE
PRODUCTION
Oil G
(MBbis) (MMC

as
;F)

STATEWIDE TOTAL 149 46 88 3 286 11457913 11676964 85061782 486432 496553
1964 TOTAL 144 53 81 2 280 14481960 13942784 77381318
1. Statistic compiled by Dr. Charles Tootle, Florida Bureau of Geology, Oil and Gas Section.
2. Fields are listed In order from north to south.
3. Plugged and abandoned oil fields.

PRO Producing Wells
INJ Injection Wells
SI Shut In Wells
TA Temporarily Abandoned Wells
TOT Total No. Wells

Bbls -
MBbls -
MCF -
MMFC -

Barrels (42 US Gallons)
Thousand Barrels
Thousand Cubic Feet
Million Cubic Feet

Abbreviations:

31

APPENDIX II

1985 DRILLING ACTIVITY

TABLE I, 1985 FIELD WELLS DRILLED

Wl1 andW Operator*Well
Permit No. Name & No.

Drill Floor
Completion Elv., Ft.
Location Doa Above MStL

JAY FILWD4
Same Roa W-15713 Exxon Corp.-Leanon
P-1146 Hawthorne No. 5-7

Santa Rosa W-15M6 Exxon Corp.-E. G.
P-1180 Jefrey, et. a
No. 6-e

MT. CARMEL FIELD
Santa Rosa W-15734
P-1164

8UNNILAND FiELD
COwer W-15754
P-1142

BEAR ISLAND FIELD
Cooller W-15706
P61118A

RACCOON POINT FIELD
Collier W-1573S
P-1141

LL & E-Wolf.-
Hendricks No.
36-1A

Exxon Corp.-
ColMr Co. No.
19-2

Exxon Corp.-
Collier Co. No.
2-10A

Exxon Corp.-
Collier Land &
Cattle Corp.
No. 2-1

2273' FNL &
1601 FWL
Se. 5,
TSN. R29W
228 FSL &
884' FEL
Sec. 6
TN. R29W

2-214-5

11-14465

191.2' FNL & 45-86
38844' FWL
Se. 3.
T8N. R29W

271.4A FNL & 3-15-5
2114.35' FWL
Sec. 19.
T48S, mR30E

SHL:

1531.9 FSL &
63&1 FWL
Sec. 1
BHL:
272' FSL &
40W FEL
Sec. 2
T498, R30E

SHLL
723' FNL &
707 FWL
BHL*

247.5

250.6
(NOVO)

206

42.5

2-13-45 3S.6
(NGVD)

)-185

15.780

15,231

11,700

Completed a a
potential producer.

Completed a
potential producer.

Plugged & abandoned
Sa dry hole. 4-5-85.

Completed as a
potential producer

MD:12.000 Completed as a
TVD:11.606 potential producer.

MD:12.712 Completed as a
TV:11,464 potential producer.

Total
Depth Ft.

State

::-"-* No.. Nam,- A -No.. ..

CfaMh

1

Collier

Collier

Collier

Collier

1320' FNL &
1320' FEL
Sec. 2,
T52S, R34E
SHL: 1-3-85
1821.9' FSL &
796.8' FEL
Sec. 28

W-15718 Exxon Corp.-
P-1149 Collier Land &
Cattle Corp.
No. 27-3

No W-no.5 Exxon Corp.-
P-1150 Collier Land &
Cattle Corp.
No. 28-4

W-15755 Exxon Corp.-
P-1162 Collier Land &
Cattle Corp.
No. 27-2

W-15859 Exxon Corp.-
P-1167 Collier Land &
Cattle Corp.
No. 22-3

11-6-85

BHL:
1320' FSL &
1320' FEL
Sec. 28,
T51S, R34E
SHL: 5-13-85
1985.5' FSL &
745.1' FEL
Sec. 28
BHL:
1320' FNL &
1320" FWL
Sec. 27,
T51S. R34E
SHL: 12-6-85
2843' FNL &
669 FEL
Sec. 28

BHL.
1320' FSL &
1320' FWL
Sec. 27,
T51S, R34E
SHL:
1651' FSL &
809 FEL

MD:12.044
TVD:11,500

Completed as a
potential producer.

35

34.9

35

35

BHL:
1320' FSL &
1320' FWL
Sec. 22,
TS1S. R34E
1. Florida Bureau of Geology well number for samples (cuttings or core chips).
2. For directionally drilled wells, SHL Is surface hole location. BHL Is bottom hole location.
3. MD: measured depth; TVD: true vertical depth (determined by directional survey).
4 Fields are listed in order from north to south.
5., Well samples have not been submitted yet.

MD:11,654 Completed as a
TVD:11.600 potential producer.

MD:12,370 Completed as a
TVD:11,513 potential producer.

MD:13,670 Completed as a
TVD:11,800 potential producer.

TABLE II. 1985 WILDCAT WELLS DRILLED

Well' and Operator-Well
Permit No. Nnme & No.

Drill Floor
Completion Elev.,. Ft.
Location2 Date Above MSL

NORTHWEST FLORIDA
Escambla W-15873
P-1172

Citis Service
Oil & Gat-Lizenby
No. 5-4

Escambia W-15843 Primary Fuels, Inc.
P-1177 Robert O'Farrell
No. 22-2

Santa Rosa W-15746 McMoran Oil & Gas
P-1159 Co.-J. Ed Golden,
et al. No. 22-1

Santa Rosa W-15711 Smacko, Ltd.-R.W.
P-1160 Blackmon. Jr. No.
16-1

Santa Rosa W-15874 Spooner Petroleum
P-1178 Co.-ChampIon Inter-
national No. 5-4

Santa Rou W-15865 Tenneco Oil Co.-
P-1185 Champion Interna-
tional No. 3-4

NORTH FLORIDA
Suwannee W-18877
P-1181

Palmer Petroleum,
Inc.-Vining No. 1

1620 FSL &
1540 FWL

11-1-85

Sec. 5,
T5N, R32W
1133.3' FNL & 114-865
1276.7' FWL
Sec. 22.
TSN, R32W
1032' FNL & 4-19-85
1029 FEL
Sec. 22.
T3N. R28W
1165' FNL & 2-1-85
1282' FEL
Sec. 16,
TSN, R29W
1047.7 FSL & 12-27-85
1083.9 FEL
Sec. 5,
T3N,R28W
1320' FSL & 12-20-85
1320' FEL
Sec. 3,
T3N, R30W

583' FNL & 12-13-85
752' FEL
Sec. 2,
T4S, R12E

280
(GL)

270

221

271

75

221

88.8

18,00

1M744
16.73

15.300

16.580

17,050

6,888

Plugged a abandoned
as a dry hole, 11-5-85

Plugged & abandoned
as a dry hole, 11-8-85.

Plugged & abandoned
as a dry hole, 4-19-85.

Plugged & abandoned
as a dry hole, 2-1-85.

Plugged & abandoned
as a dry hole, 12-27-85.

Plugged & abandoned
as a dry hole, 12-20-85.

Plugged & abandoned
as a dry hole, 12-13-85.

County

Total3
Deoth. Ft.

e Fitl t It us I .. I FI.

8taus

SOUTH FLORIDA
Broward W-15765
P-1169

Collier

Collier

Collier

Lee

Lee

Sabine Corp.-
Miccosukee No.
32-1

W-15841 Hughes Eastern
P-1086 Petr., Ltd.-Collier
Co. No. 10-2

W-15796 Hughes Eastern
P-1140 Petr., Ltd.-Gerry
Brothers No. 33-2

W-15844 R. K. Petroleum
P-1170 Corp.-Rex Proper-
ties No. 33-2

W-15756 Exxon Corp.-A.
P-1165 Kaplan Trustees,
et al. No. 32-1

W-15845 Hughes Enterprises-
P-1183 Hughes-Rutledge
No. 9-4

1616' FNL & 6-28-85
2310' FEL
Sec. 32,
T49S, R35E
1382' FNL & 9-9-85
1567 FWL
Sec. 10,
T53S,. R34E
SHL: 10-15-85
1295' FNL &
11040 FWL

BHL:
695' FNL &
1040' FWL
Sec. 33,
T49S,. R31E
1440' FNL & 12-6-85
952' FWL
Sec. 33,
T46S, R28E.
1412' FNL & 5-19-85
1208' FEL
Sec. 32,
T45S, R27E
SHL: 11-15-8
1185' FNL &
2464' FWL

30

37

43.4

52

11,604

11,5647

Plugged & abandoned
as a dry hole, 6-28-85.

Plugged & abandoned
as a dry hole, 9-9-85.

MD:11,632 Plugged & abandoned
TVD:11,591 as a dry hole, 10-15-85.

11,565

11,800

Completed as a
producer.

Plugged & abandoned
as a dry hole, 5-19-85.

MD:11,778 Plugged & abandoned
TVD:11,350 as a dry hole, 11-15-85.

BHL:
1640' FSL &
1564' FEL
Sec. 9,
T44S, R26E

1. Florida Bureau of Geology well number of samples (cuttings or core chips).
2. For directionally drilled wells, SHL is surface hole location. BHL Is bottom hole location.
3. MD: measured depth; TVD: true vertical depth (determined by directional survey).

i

5

TABLE III. WELLS DRILLED DURING 1985 IN EASTERN PLANNING AREA, GULF OF MEXICO

WELL

DRILLER'S
DEPTH,

RTE,1

AREA NO. OPERATOR LOCATION FEET FT. MBL REMARKS
Destin Dome OCS-G-6417 Shell Block 160 17761 105 Smackover-Norphlet well on Destin Dome.
Well No. 1 Rumored to have had goo dahow In Norphlet.
Shell-Amoco bids In sale 94, In December, 1985,
support this belief. Set open hole plug.
Abandoned 12-85.

Destin Dome OCS-G-6417 Shell Block 160 16993 105 Began drilling 5-9-85. Smackover-Norphlet
Well No. 2 test. Abandoned 8-21-85 without testing.
Destin Dome OCS-G-6428 Exxon Block 284 17500 73 Began drilling 6-28-85. Smackover-Norphlet
test drilled on Destin Dome. Abandoned
11-85 without testing.
Destin Dome OCS-G-6438 Chevron Block 422 22222 83 Began drilling 7-2-85. Smackover-Norphlet
test. Abandoned 12-85 without testing.

Gainesville OCS-G-6456 Sohlo Block 707 15994 100 Began drilling 6-3-85, T.D. In Paleozolcs(?).
Well believed to have penetrated thick Eagle Mills
(Triassic) section. Abandoned without testing.

Pensacola Block OSC-G-6391 Sohlo Block 948 18958 85 Began drilling 2-18-85. Well drilled on Louann Salt
structure. Seven Inch liner cemented at 18956
feet. Well tested In both Norphlet and Smackover.
Abandoned 10-16-85.

1. RTE: Rotary Table Elevation.

37

APPENDIX III

DISCOVERY WELL DATA

FLORIDA OIL FIELD DISCOVERY WELL DATA

Discovery Permit
Date No.

Perforations Total Name of Produc-
Field County or Open Hole Depth Ing Formation

Discovery Oil Gravity,

Status

Degrees API

42 Sunnlland
167 Forty Mile Bend
315 Sunoco Felda
371 West Felda
401 Lake Trafford
417 Jay
504 Mt. Carmel

523 Blackjack Creek

563 Bear Island
662 Sominole
712 Lehigh Park
881 Sweetwater Creek
865 Baxter Island
904 Mid-Felda
829 Raccoon Point
897 Pepper Hammock
1070 Townsend Canal
1125 Bluff Springs
1170 Corkscrew
1194 McClellan

Collier
Dade
Hendry
Hendry
Collier
Santa Rosa
Santa Rosa

11,602-11,626
11,322-11,339
11,472-11,485
11,486-11,489
11,870-11,892
15,470-15,524
15,260-15,280

Santa Rosa 15,790-15,900

Collier
Hendry
Lee
Santa Rosa
Collier
Hendry
Collier
Collier
Hendry
Escambla
Collier
Santa Rosa

11,589-11,595
11,415-11,420
11,389-11,394
11,299-14,340
11,512-11,515
11,492-11,496
11,410-11,414
11,629-11,633
11,416-11,421
16,332-16,339
11,547-11,565
14,072-14,090

11,626 Sunniland
11,577 Sunniland
11,485 Sunniland
11,675 Sunniland
11,987 Sunniland
15,984 Smackover
15,399 Smackover
& Norphlet
16,235 Smackover
& Norphlet
11,817 Sunniland
11,051 Sunniland
11,630 Sunnlland
14,611 Smackover
11,823 Sunniland
11,686 Sunniland
11,658 Sunniland
11,897 Sunniland
11,462 Sunniland
16,800 Smackover
11,565 Sunniland
14,475 Smackover

9.26-43
2-1-54
7-22-64
6-2-66
3-30-09
6-15-70
12-19-71

2-14-72

12-6-72
11-14-73
7-30-74
4-22-77
8-11-77
10-13-77
6-20-78
9-28-78
6-27-82
3-25-84
11-10-85
2-28-86

Pumping
Pumping
Pumping
Pumping
Pumping
Flowing
Flowing

Flowing

Pumping
Pumping
Pumping
Pumping
Pumping
Pumping
Pumping
Pumping
Pumping
Flowing
Swab Test
Flowing

--~~-

39

APPENDIX IV

1985 GEOPHYSICAL EXPLORATION ACTIVITY

1985 GEOPHYSICAL EXPLORATION ACTIVITY

Surveyed
For

G031-86

G-32-86

G-33-88

0-34-88

0-35-86

G-386-88

G-37-88

0-38-85

G-39-85

G-40-85

G-41-85

G-42-85

G-43-85

G-44-85

G-45-85

G-46-85

G-47-85

Texaco

Seminole
Expl.
Seale Pros

GFS

Western
Geophys,
GFS

Geco

GFS

GFS

Selecom
Delta Untd.
Selscom
Delta Untd.
Shell West-
ern E & P
Geo Seism.
Serv.
Geco

GFS

GFS

Conoco

Inc. Inc.

Osophysl-
Permit eal Co.

Conoco Santa Rosa 7-12-85

Texaco

Seminole
Expl.
Edwin &
Berry Cox
Bel North
Petrol.
Western
Geophys,
Inexco

Geco

Arco

MC Moran

Arco

Arco

Shell West-
ern E & P
Geo Seism.
Serv.
Geco

Bel North
Petrol.
Union Oil

County

Collier

Collier

Collier

Santa Rosa

Esc., Sta Ri
Oklsa, Witn
Santa Rosa

Collier &
Hendry
Escambla

Escambia

Santa Rosa

Santa Rosa

Hendry

Walton

Collier

Escambla

Santa Rosa

Gelatin

Permit Expiration
Approved Date Status

Application
Withdrawn
Application
Pending
10-4-85 4-2-86 Survey
Cancelled
3.6-85 9-3-85 Completed

$a, Application
Pending
3-18-85 9-14-85 Completed

5-17-85 5-12-86 Partially
Completed
3-27-85 9-23-85 Completed

3-27-85 9-23-85 Completed

3-29-85 9-25-85 Permit
Expired
6-17-85 12-14-85 Completed

4-9-85 4-4-86 Completed

Application
Withdrawn
9-24-85 3-23-86 Permit
Expired
Application
Withdrawn
7-19-85 1-15-86 Completed

150-180 7.5

1-8-86 Completed Vibrosels N.A. N.A.

Energy
Source

Seismic
Gelatin
Thumper

Explosives

Seismic
Gelatin
Alrgun

Seismic
Gelatin
Airgun or
Vibrator
Seismic
Gelatin
Seismic
Gelatin
Seismic
Gelatin
Seismic
Gelatin
Watergel
Explosive
Seismic
Gelatin
Vibrator
Comp. Air
Seismic
Gelatin
Seismic

Depth,
Ft.

10-20

N.A,

10-20

150180

N.A.

150180

N.A.

80-100
150-180
150-180

80-100
150-180
80-100
150-180
110

150-180

N.A.

80-100
150-180
80-100

N.A.

I

Charge
Slme, Lbs

0.25-2.5

N.A.

1

10-15

N.A.

10-15

N.A.

2.5-5

10-15

5-10

5-10

20

20

N.A.

2.5
7.5
2.5

Shot Hole
Spring, PF

220

NA.

220

330

N.A.

330

N.A.

330

330

165

1685

80

330

N.A.

440

440

CII-

survey
Length, ml. Comments

107

Not
Stated
10

7

350 Offshore

34.5

340 Only 50 mil
Surveyed
57

5

30

30

14.25

8

45.5 Partly Offsh

4.5

4.5

ore

as

Southern Okeechobee 7-19-85
Seismic
Western Madison 7-10-85
Geophys.

G-50-85 Shell West- Shell West- Dde, PIm 9-11-85
ern E & P ern E & P Bch, Cir, Brwd
G-51-85 Seismic Cities Escambia & 9-24-85
Experts Service Santa Rosa
G-52-85 J.M. J.M. Glades, 12-20-85
Huber Huber Highlands

G-53-85 Western
Geophys
G-54-85 Geco

Western
Geophys
Geco

Escambia

Bay, Calhoun,
Gulf, Liberty,
Franklin

G-55-85 Southern Southern Hendry &
Seismic Seismic Collier
G-56-85 Southern Gulf Coast Escambia 11-27-85
Seismic Geodata
G-57-85 Petty-Ray Petty-Ray Lib, Frank., 11-19-85
Geophys Geophys Wakulla
G-58-85 GFS LA.Land Santa Rosa 11-8-85
& Expl.
G-59-85 Shell West- Shell West- Hendry & 2-10-86
ern E & P ern E & P Palm Bch
G-60-85 GFS Mobil Escambla 12-23-85

G-61-85 Western Tenneco Escambla & 2-4-86
Geophylcal Oil E&P Santa Rosa

G-48-85 Southern
Seismic
G-49-85 Western
Geophys.

Completed

Completed

Seismic
Gelatin
Dynamite

1-15-86

1-7-85

3-10-86

9-19-86 On Hold Dynamite 100 20

6-18-86 Cancelled Seismic 6
Gelatin 10
80-

5-26-86

5-18-86

5-7-86

8-9-86

6-21-86

5-5-86

Application
Withdrawn
Application
Pending

Application
Pending
Completed

Completed

Dynamite 12C

0.25 220

10 "165

N.A. 280

440 11.3

.55
1.1
100 "Small"
) 20

Vlbrosels N.A. N.A.

Seismic
Gelatin
Seismic
Gelatin
Vibroesis

20

150

N.A.

Completed Vibroseis N.A.

Completed Seismic 11(
Gelatin
Completed Seismic 80-
Gelatin
Completed Dynamite 70

110

5280
440

66 Mini-holesurvey

6

N.A. 420

220 15.5

20 161 7.5

N.A. N.A. 246

N.A. N.A. 8

20 60 33

150 10-20

330 22.5

5 165 75

Total Miles In Applications
Total Actual Surveyed
In South Florida
In North Florida, Panhandle
In North Florida, Peninsula
Total Pending
Total Withdrawn, Cancelled, or Expired

Completed Vibrosels N.A. N.A.

2327.05
963.25
392.25
519.0
52.0
796.8
567.0

0

APPENDIX V

OIL AND GAS RELATED THESES HELD BY
THE FLORIDA GEOLOGICAL SURVEY LIBRARY

Grinnell, Philip C., Jr., 1976, The Sunniland Limestone within the Forty
Mile Bend Area, Monroe and Dade Counties, Florida: Tallahassee, FL,
Fla. State Univ.

Hearn, Frank P., 1984, Pre-Punta Gorda Sediments from the Bass,
Collier Company, 12-2 Well, South Florida: Lafayette, LA, Univ. of
Southwestern Louisiana.

Heron, Stephan D., III, 1982, Depositional and Diagenetic History of
Selected Mesozoic Sediments of the South Florida Basin: Lafayette, LA,
Univ. of Southwestern Louisiana.

Laird, John W., 1985, Diagenetic Controls on Reservoir Characteristics
and Development in the Jurassic Norphlet Formation, Escambia
County, Alabama: University, AL, Univ. of Alabama.

Pontigo, Felipe Antonio, Jr., 1982, Pre-Haynesville Stratigraphy and
Structural Geology of the Apalachicola Embayment, Petrology and
Paleoenvironmental Interpretation of the Smackover Formation: Talla-
hassee, FL, Fla.State Univ.

Raasch, Albert C., Jr., 1954, The Sunniland Oil Field of Collier County,
Florida: Tallahassee, FL, Fla. State Univ.

Vaughan, R. Lee, 1985, Diagenetic Effects on Reservoir Development in
the Upper Jurassic Norphlet Formation, Mobile and Baldwin Counties,
and Offshore Alabama: University, AL, Univ. of Alabama.

43

PART II

THE BROWN DOLOMITE ZONE OF THE LEHIGH ACRES
FORMATION (APTIAN) IN THE SOUTH FLORIDA BASIN-
A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE

By

Albert V. Applegate

44 CONTENTS
Page

Acknowledgements .......................................... 45

Abstract ..................................................... 46

Purpose of study ............................................. 46

Method of study .............................................. 46

Metric conversion factors ..................................... 47

Lithology .............................................. ...... 47

Stratigraphic relationships .................................... 51

Geochemistry ................................................ 54

Structure .................................................... 55

Summary .................................................... 57

References .................................................. 58

Appendix I Summary of well data ............................ 59

Appendix II Drill stem test data from Brown Dolomite Zone ...... 66

ILLUSTRATIONS

Figure
1 Isopach of the Brown Dolomite ..................... 48
2 Structural map of the Brown Dolomite ............... 49
3 Isopach of the porous Brown Dolomite ............... 50
4 Generalized geological column Lower Cretaceous-
Jurassic (?) rocks; south Florida Basin ............... 52
5 Control wells ....................................... 53
6 Structural features in Florida and offshore ............ 56

45

ACKNOWLEDGEMENTS

Geological Survey staff members reviewed and edited this report. Jim
Jones and Ted Kiper drafted and photographed the figures. George
Winston (consulting geologist, Coral Gables, Florida) provided geo-
logic information and advice.

THE BROWN DOLOMITE ZONE OF THE
LEHIGH ACRES FORMATION (APTIAN)
IN THE SOUTH FLORIDA BASIN-
A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE

by

Albert V. Applegate

ABSTRACT

The best development of the Brown Dolomite onshore is in Charlotte
and surrounding counties in the northern part of the South Florida
Basin at a depth of approximately 12,000 feet. Here, the Brown Dolomite
zone attains a maximum thickness of 100 feet, of which one-half is
usually porous and capable of high volume fluid production. Offshore,
the maximum thickness occurs near the Marquesas Keys, where
approximately 400 feet of mostly porous dolomite has been encoun-
tered. Although very little oil staining has been found in the Charlotte
County area, staining has been observed in two Marquesas wells.
The best possibility for finding oil in the Brown Dolomite appears to
be in the offshore portion of the South Florida Basin. Brown Dolomite is
present in at least three wells on the Sarasota Arch and probably con-
tinues around the rim of the basin southeast to the Marquesas where
thick vugular dolomite is present. Stratigraphic and structural traps
associated with this dolomite, which is capped by dense limestone and
anhydrite, may have led to the formation of giant oil fields.

PURPOSE OF STUDY

The potential economic importance of the Brown Dolomite in the
offshore area of the South Florida Basin, as well as in the area where it
was originally described, prompted this study. This information will
help geologists to decide if the possibility of finding oil in this zone is
worth the expense of drilling the additional 1,000 feet below the Sunni-
land Formation.

METHOD OF STUDY

Core chips and cuttings of wells drilled through the Brown Dolomite
zone were studied using a binocular microscope. Appendix I shows
these wells. Information listed in Appendix I includes formation tops
from the Punta gorda Anhydrite to total depth, net dolomite, porous
dolomite, Jost circulation, and other pertinent data. from these data, an
isopach map of the Brown Dolomite (Figure 1) was prepared.

Appendix 2 lists data on all drill stem tests. Water recoveries in these
tests show that the wells tested had sufficient porosity and permeability
to be capable of oil production.
A structural map (Figure 2) using subsea depths to the top of the
Punta Gorda Anhydrite was made. Wells penetrating the Punta Gorda
Anhydrite were used in the preparation of this map.
An isopach map (Figure 3) of the porous interval in the Brown Dolom-
ite was prepared, utilizing available data. In early wells where sonic and
neutron logs were not available, cores, cuttings, caliper surveys, drilling
time logs, and lost circulation intervals were important factors in arriv-
ing at estimates of the thickness of the porous interval as well as
estimating the actual porosity. In those wells in which sonic or neutron-
density logs were available, porosity calculations were found to be in
fair agreementw.ith estimates made from cores and cuttings.

METRIC CONVERSION FACTORS

The Florida Bureau of Geology, in order to prevent duplication of
parenthetical conversion units, inserts a tabular listing of conversion
factors to obtain metric units.

Multiply by to obtain
feet 0.0348 meters
miles 1.6090 kilometers

LITHOLOGY

The texture of the Brown Dolomite varies from euhedral to anhedral,
and from coarse to very fine grained. It is often vugular near the top of
the section. Drill stem tests made in the Brown Dolomite show that it is
capable of high fluid production. Much of the Brown Dolomite has fossil
ghosts and other evidence of secondary origin. In general, the dolomite
becomes less porous from top to bottom which may be partially due to
porosity changes in the original limestone.
In the Tribal Exxon Gulf Coast Realties 12-2 well (P-727) a core
cutting the Brown Dolomite is predominantly limestone due to its
downdip location in the basin. In this well the lowermost limestones
exhibit the lowest porosity. Dolomite has an average porosity of nine
percent in contrast to about four percent for the limestone.
Permeability was low or non-existent in both the limestone and
dolomite. This particular well was a key well in understanding the
Brown Dolomite zone. It was cored through the Brown Dolomite zone
with 100 percent core recovery. An analysis of each foot of the core was
made by All Points, Inc., of Houston, Texas. Geophysical logs that were
run included gamma ray, sonic, caliper, neutron-density and induction
electrical.

"-~ t0o THICKNESS IN FEET

N

0 26 mile
SCALE

Figure 1. Isopach of the Brown Dolomite.

SCALE 0

Figure 2. Structural map of the Brown Dolomite.

I
I N ARDeg

Q'
0*
A*

~ 20 THuEc5Ne no FeET

N 1

0 ac mla
SCALE

so ;O

Figure 3. : opach of the porous Brown Dolomite.

In wells drilled prior to the introduction of the compensated neutron
density log it is mandatory to have cores or good cuttings in order to
make a reliable estimate of net dolomite. Due to lost circulation in the
more porous zones, samples may be of very poor quality, completely
missing, or consist of little but lost circulation material. Another prob-
lem in the better porosity zones is washout. When this occurs porosity
calculations from geophysical logs are not reliable.

STRATIGRAPHIC RELATIONSHIPS

The term Brown Dolomite, or "CD Dolomite" as it was often called by
Banks, was first used in two reports (Banks, 1964a and 1964b). Banks
states (1964a, p. 3) that, "the Brown Dolomite occurs in the first few feet
or the first few hundred feet of the Choffatella decipiens zone." In a
stratigraphic section from Lee to Manatee counties (Banks, 1964b) the
top of the Brown Dolomite lies 300 feet below the base of the Punta
Gorda Anhydrite.
The Choffatella decipiens zone was not described by Banks, but in
various cross sections by Paul and Esther Applin (1965, plates 8, 9, 11),
it has a thickness of approximately 1,000 feet in the area where the
Brown Dolomite is present. The Applins considered the Choffatella
decipiens zone to be lowermost Trinity age lowermostt Comanchean).
It lies just above their Fort Pierce Formation of Late Jurassic (?) or Early
Cretaceous age. Choffatella decipiens is a large benthic foraminifera
which ranges throughout Early Cretaceous (Valanginian to Albian). It
has been identified in limestone in the Caribbean region (Maync, 1950).
The Applins (1965, plate 5) found the Choffatella decipiens in the upper
250 feet of the Fort Pierce Formation in their type well, the Amerada
Cowles Magazine No. well (P-259) in St. Lucie County, Florida, and in
several other wells penetrating this formation.
A new nomenclature for the pre-Punta Gorda rocks in the South
Florida Basin was introduced by Applegate, et al. (1981). In this nomen-
clature (Figure 4), the Lehigh Acres, an early Trinity age formation, lies
beneath the Punta Gorda. This formation consists of three members,
from youngest to oldest: the Able Member, 290-feet thick, composed
principally of anhydrite and limestone; the Twelve Mile Member, 320-
feet thick predominately limestone and dolomite, and the West Felda
Member, 40-feet thick, composed of calcareous shale and dark gray,
argillaceous limestone.
The Brown Dolomite zone, which lies entirely within the Twelve Mile
Member, is found at a minimum depth of about 50 feet below the top of
the member. Onshore the Brown Dolomite zone is encountered only in
the up-dip of the South Florida Basin. With the exception of its presence
in the two Marquesas wells in the Florida Keys (Figure 5, P-275, P-284) it
is not present in the area below the 11,900 foot contour of the Punta
Gorda Anhydrite.
The best onshore development of the Brown Dolomite occurs in
northern Lee, northern Hendry, Charlotte, Glades, southeast De Soto

Figure 4. Generalized geological column of Lower Cretaceous -
Jurassic (?) rocks in the south Florida Basin.

53

ATEE HARDEE HIGHLANDS S
j 7 _I OKEECHOBEE ST. LUCIE A
1236 062 I 259
DESOTO I CARLTON S

SHARLTE LADES LAKE ------
7 A750 4 L OKEECHOBEE PALM BEACH
&31 0 152 47

35 0424 265ie
S I|5B J BROWARD
727

0778 9280 --
DADE

NO BROWN DOLOMITE MONROE
NOTED IN THESE WELLS
IN LEHIGH ACRES FM. I

148
N ,
0*902

0 25 mile8
SCALE

284 0
0

Figure 5. Location map of control wells.

and southwest Highlands counties. The best development encountered
was in the Humble-Treadwell 1-A well, (Sec. 17, T42S, R23E) in south-
ern Charlotte County, where there is at least 100 feet of dolomite. The
thickest offshore section, with the exception of the previously dis-
cussed Marquesas wells, is found to the west-southwest in the two
California-Coastal wells (P-289, P-297) in the FSL 224-B lease offshore
from Lee County (Figure 5). Offshore the dolomite is known to continue
to the west, where it has been found in at least three locations on or near
the Sarasota Arch.
From the Humble-Treadwell well, the thickest section of the Brown
Dolomite zone closely follows the 11,600-foot structural contour of the
Punta Gorda Anhydrite southeast to the Humble-Lehigh Acres well in
Lee County, and then turns abruptly to the northeast, where it has an
estimated thickness of 70 to 75 feet in southeast DeSoto County and
southwest Highlands County. The occurrence of the rather thick sec-
tion here may have been influenced by the Peninsular Arch.
An estimated 38 feet of the Brown Dolomite zone is present in the
Mobil-Phillips Seminole "C" well (P-565B) in Hendry County. No deep
wells have been drilled to the southeast between this well and the
Sinclair-Wiliams (P-148) and the Robinson-IIF well, both of which are
located on Key Largo in eastern'Monroe County. Twenty-eight feet of
very fine-grained anhydriticdolomite was found in the Sinclair-Williams
well (P-148).
Two wells in the Marquesas Keys which have a thick porous dolomite
section are the Gulf-FSL 826Y well (P-275) and the Gulf-California OCS
Block 28 well (P-284). Dolomite found in the Gulf 826Y well is highly
porous and was considered by Banks (1964a and 1964b) to be the same
Brown Dolomite which he had studied in Lee, Charlotte and Sarasota
counties. The Gulf-California Block 28 well was found to have a consid-
erably thinner dolomite section than the 826Y well.
George Winston (personal communication, 1984) also believes that
this dolomite is in the Twelve Mile Member of the Lehigh Acres Forma-
tion. It is doubtful that a definitive correlation can be made until more
deep control is available between the Florida Keys and the mainland.

GEOCHEMISTRY

The petroleum source rock study by Palacas (Palacas, et al., 1981) of
pre-Punta Gorda rocks from widely scattered boreholes in the South
Florida Basin revealed that the upper part of the Pumpkin Bay Forma-
tion, and to a lesser extent, part of the Lehigh Acres Formation have the
best source potential in the lower beds. The richest of these rocks
studied to date are in the Humble-Lehigh Acres well (P-407) in Lee
County and the Gulf FSL No. 373 well (P-22) on Big Pine Key (Figure 5).
This is a favorable factor for the establishment of commercial oil pro-
duction in the Brown Dolomite zone.

55
Another factor favoring possible oil generation in the Brown Dolomite
is its depth. It lies approximately 1,000 feet below the Sunniland Forma-
tion. The Sunniland is considered to be near the top of the "oil window,"
as it has a low gas-oil ratio (approximately 100 cubic feet of gas per stock
tank barrel of oil) and a relatively low API gravityt250. This additional
depth should ensure that, if oil is found in the Brown Dolomite, it wil be
higher gravity oil with a higher gas-to-oil ratio than the oil presently
being produced from the Sunniland Formation.

STRUCTURE

The South Florida Basin has experienced at least three major
changes in size and shape since its formation following the separation
of North America from Africa and South America. This division is
thought to have occurred during the Triassic and Early Jurassic, peri-
ods noted for red beds and volcanic activity in both north and south
Florida (Barnett, 1975; Smith, 1982; Chowns and Wiliams, 1983; and
Klitgord, et al., 1984).
According to Winston (personal communication, 1983) the geogra-
phic extent of the South Florida Basin in early Comanchean time and
during the deposition of Brown Dolomite was limited to atriangular area
roughly 200 miles on each side. To the east, the basin was limited by the
Cay Sal Arch, (Figure 6) which came into existence in early Coman-
chean time. This feature extended north from Cuba through Cay Sal
and east to Key Largo and up the present Florida Straits. The basin
bends gently around the north side of Lake Okeechobee to the south
side of the offshore Sarasota Arch. The Sarasota Arch extends in a
southwest direction from Sarasota County across the west Floridashelf
to the reef-capped Comanchean continental edge along the west Flor-
ida escarpment. Along the arch, basement is encountered offshore at
depths ranging from about 10,000 to 12,000 feet. This arch separates the
South Florida Basin from the Tampa Basin, which lies to the north of the
arch. After reaching the continental edge, the basin follows the escarp-
ment to the southeast.
Although later offshore drilling in the eastern Gulf of Mexico has
changed the shape of the northern part of the South Florida Basin, as
originally proposed by Oglesby (1965), many of his concepts appear to
be valid. The Cretaceous section shown in his various South Florida
Basin maps (based on seismic interpretation) thins significantly as it
approaches the western edge of the Continental Shelf. If this general
configuration of the basin is correct, it is probable that the Brown dolo-
mite is present at the western edge of the basin and will provide a
tempting target for exploratory drilling. This assumption is further bol-
stered by the presence of a thick dolomite section in the Marquesas
wells and the lack of dolomite in the Gulf-FSL 373 well (P-22) to the east
on Big Pine Key. This area was structurally low during the Early
Cretaceous.

and southwest Highlands counties. The best development encountered
was in the Humble-Treadwell 1-A well, (Sec. 17, T42S, R23E) in south-
ern Charlotte County, where there is at least 100 feet of dolomite. The
thickest offshore section, with the exception of the previously dis-
cussed Marquesas wells, is found to the west-southwest in the two
California-Coastal wells (P-289, P-297) in the FSL 224-B lease offshore
from Lee County (Figure 5). Offshore the dolomite is known to continue
to the west, where it has been found in at least three locations on or near
the Sarasota Arch.
From the Humble-Treadwell well, the thickest section of the Brown
Dolomite zone closely follows the 11,600-foot structural contour of the
Punta Gorda Anhydrite southeast to the Humble-Lehigh Acres well in
Lee County, and then turns abruptly to the northeast, where it has an
estimated thickness of 70 to 75 feet in southeast DeSoto County and
southwest Highlands County. The occurrence of the rather thick sec-
tion here may have been influenced by the Peninsular Arch.
An estimated 38 feet of the Brown Dolomite zone is present in the
Mobil-Phillips Seminole "C" well (P-565B) in Hendry County. No deep
wells have been drilled to the southeast between this well and the
Sinclair-Wiliams (P-148) and the Robinson-IIF well, both of which are
located on Key Largo in eastern'Monroe County. Twenty-eight feet of
very fine-grained anhydriticdolomite was found in the Sinclair-Williams
well (P-148).
Two wells in the Marquesas Keys which have a thick porous dolomite
section are the Gulf-FSL 826Y well (P-275) and the Gulf-California OCS
Block 28 well (P-284). Dolomite found in the Gulf 826Y well is highly
porous and was considered by Banks (1964a and 1964b) to be the same
Brown Dolomite which he had studied in Lee, Charlotte and Sarasota
counties. The Gulf-California Block 28 well was found to have a consid-
erably thinner dolomite section than the 826Y well.
George Winston (personal communication, 1984) also believes that
this dolomite is in the Twelve Mile Member of the Lehigh Acres Forma-
tion. It is doubtful that a definitive correlation can be made until more
deep control is available between the Florida Keys and the mainland.

GEOCHEMISTRY

The petroleum source rock study by Palacas (Palacas, et al., 1981) of
pre-Punta Gorda rocks from widely scattered boreholes in the South
Florida Basin revealed that the upper part of the Pumpkin Bay Forma-
tion, and to a lesser extent, part of the Lehigh Acres Formation have the
best source potential in the lower beds. The richest of these rocks
studied to date are in the Humble-Lehigh Acres well (P-407) in Lee
County and the Gulf FSL No. 373 well (P-22) on Big Pine Key (Figure 5).
This is a favorable factor for the establishment of commercial oil pro-
duction in the Brown Dolomite zone.

55
Another factor favoring possible oil generation in the Brown Dolomite
is its depth. It lies approximately 1,000 feet below the Sunniland Forma-
tion. The Sunniland is considered to be near the top of the "oil window,"
as it has a low gas-oil ratio (approximately 100 cubic feet of gas per stock
tank barrel of oil) and a relatively low API gravityt250. This additional
depth should ensure that, if oil is found in the Brown Dolomite, it wil be
higher gravity oil with a higher gas-to-oil ratio than the oil presently
being produced from the Sunniland Formation.

STRUCTURE

The South Florida Basin has experienced at least three major
changes in size and shape since its formation following the separation
of North America from Africa and South America. This division is
thought to have occurred during the Triassic and Early Jurassic, peri-
ods noted for red beds and volcanic activity in both north and south
Florida (Barnett, 1975; Smith, 1982; Chowns and Wiliams, 1983; and
Klitgord, et al., 1984).
According to Winston (personal communication, 1983) the geogra-
phic extent of the South Florida Basin in early Comanchean time and
during the deposition of Brown Dolomite was limited to atriangular area
roughly 200 miles on each side. To the east, the basin was limited by the
Cay Sal Arch, (Figure 6) which came into existence in early Coman-
chean time. This feature extended north from Cuba through Cay Sal
and east to Key Largo and up the present Florida Straits. The basin
bends gently around the north side of Lake Okeechobee to the south
side of the offshore Sarasota Arch. The Sarasota Arch extends in a
southwest direction from Sarasota County across the west Floridashelf
to the reef-capped Comanchean continental edge along the west Flor-
ida escarpment. Along the arch, basement is encountered offshore at
depths ranging from about 10,000 to 12,000 feet. This arch separates the
South Florida Basin from the Tampa Basin, which lies to the north of the
arch. After reaching the continental edge, the basin follows the escarp-
ment to the southeast.
Although later offshore drilling in the eastern Gulf of Mexico has
changed the shape of the northern part of the South Florida Basin, as
originally proposed by Oglesby (1965), many of his concepts appear to
be valid. The Cretaceous section shown in his various South Florida
Basin maps (based on seismic interpretation) thins significantly as it
approaches the western edge of the Continental Shelf. If this general
configuration of the basin is correct, it is probable that the Brown dolo-
mite is present at the western edge of the basin and will provide a
tempting target for exploratory drilling. This assumption is further bol-
stered by the presence of a thick dolomite section in the Marquesas
wells and the lack of dolomite in the Gulf-FSL 373 well (P-22) to the east
on Big Pine Key. This area was structurally low during the Early
Cretaceous.

Figure 6. Structural features in Florida and offshore.

SUMMARY

Interest in the Brown Dolomite zone of the Lehigh Acres Formation
and other dolomites in the geologic column is certain to increase as
attention focuses on the petroleum potential in the offshore portion of
the South Florida Basin.
Because of porosity and permeability enhancement accompanying
the chemical processes that transform limestone into dolomite,
sucrosic dolomites are by far the most important of the carbonate
reservoir rocks.
In the northern part of the South Florida Basin, centering around
Charlotte County, no reserves or good shows have been found, even
though the geochemistry appears to be favorable. One explanation is
that, since these beds have a gentle southwest dip with no known
faulting, any oil in the Brown Dolomite could have migrated updip to the
northeast and out of the dolomite into basal clastics. Another possibility
is that no structure has been drilled. It is doubtful that further drilling in
the northern area will be forthcoming until better seismic tools are
developed or new discoveries are made in other areas of the South
Florida Basin.
The best possibility at present for new discoveries appears to be
offshore Florida where thick porous dolomites are believed to exist.
Such dolomites in a stratigraphic or structural trap could have led to the
formation of giant fields.
Any exploration program would have at least two attractive targets
before reaching the Brown Dolomite zone. The Dollar Bay Formation,
lying about 2,000 feet above the Sunniland Formation, has had very
good heavy oil shows in the Lake Okeechobee area. However, the oil,
because of low formation temperature, is not sufficiently maturated at
this updip location.
In the offshore, where the same Dollar Bay Formation could be pres-
ent, formation temperatures and resulting API gravity could be consid-
erably higher. The same reasoning applies to the Sunniland Formation.
This formation produces oil of 25-26 degrees API gravity, with a gas-to-
oil ratio of approximately 100 onshore. In the offshore, if the formation is
present, it could be deeper and have a higher gas-to-oil ratio and a
higher API gravity.
This relatively unexplored offshore part of the South Florida Basin,
with its thick Cretaceous and Jurassic (?) dolomites, coupled with
numerous anhydrite seals, offers a tempting target. Ready markets for
oil and gas, together with benign weather in the offshore, all point to the
need for a sustained driling program to thoroughly test this area.

SUMMARY

Interest in the Brown Dolomite zone of the Lehigh Acres Formation
and other dolomites in the geologic column is certain to increase as
attention focuses on the petroleum potential in the offshore portion of
the South Florida Basin.
Because of porosity and permeability enhancement accompanying
the chemical processes that transform limestone into dolomite,
sucrosic dolomites are by far the most important of the carbonate
reservoir rocks.
In the northern part of the South Florida Basin, centering around
Charlotte County, no reserves or good shows have been found, even
though the geochemistry appears to be favorable. One explanation is
that, since these beds have a gentle southwest dip with no known
faulting, any oil in the Brown Dolomite could have migrated updip to the
northeast and out of the dolomite into basal clastics. Another possibility
is that no structure has been drilled. It is doubtful that further drilling in
the northern area will be forthcoming until better seismic tools are
developed or new discoveries are made in other areas of the South
Florida Basin.
The best possibility at present for new discoveries appears to be
offshore Florida where thick porous dolomites are believed to exist.
Such dolomites in a stratigraphic or structural trap could have led to the
formation of giant fields.
Any exploration program would have at least two attractive targets
before reaching the Brown Dolomite zone. The Dollar Bay Formation,
lying about 2,000 feet above the Sunniland Formation, has had very
good heavy oil shows in the Lake Okeechobee area. However, the oil,
because of low formation temperature, is not sufficiently maturated at
this updip location.
In the offshore, where the same Dollar Bay Formation could be pres-
ent, formation temperatures and resulting API gravity could be consid-
erably higher. The same reasoning applies to the Sunniland Formation.
This formation produces oil of 25-26 degrees API gravity, with a gas-to-
oil ratio of approximately 100 onshore. In the offshore, if the formation is
present, it could be deeper and have a higher gas-to-oil ratio and a
higher API gravity.
This relatively unexplored offshore part of the South Florida Basin,
with its thick Cretaceous and Jurassic (?) dolomites, coupled with
numerous anhydrite seals, offers a tempting target. Ready markets for
oil and gas, together with benign weather in the offshore, all point to the
need for a sustained driling program to thoroughly test this area.

REFERENCES

Applegate, A. V., Winston, G. 0., and Palacas, J. G. 1981, Subdivision
and Regional Stratigraphy of the Pre-Punta Gorda Rocks (Lowermost
Cretaceous-Jurassic ?) in South Florida: Supplement to Gulf Coast
Assoc. Geol. Soc. Trans., v. 31, p. 447-453.

Applin, P. L. and Applin, E. R., 1965, The Comanche Series and Asso-
ciated Rocks in the Subsurface in Central and South Florida: U.S.
Geological Survey Prof. Paper 447.

Banks, J. E., 1964a, Oil and Gas Prospects of the Englewood Area of
Lee, Charlotte and Sarasota Counties, Florida: unpublished report for
Coastal Pet. Corp. placed in Bureau of Geology Library in Tallahassee,
Florida.

Banks, J. E., 1964b, Geologic Investigation for Petroleum in the Area of
State of Florida Drilling Lease 224-B: unpublished report for Coastal
Pet. Corp. placed in Bureau of Geology Library in Tallahassee, Florida.

Barnett, R. S., 1975, Basement Structure of Florida and its Tectonic
Implications: Gulf Coast Assoc. of Geol. Socs. Trans., v. 25, p. 122-142.

Chowns, T. M., and Williams, C. T., 1983, Pre-Cretaceous Rocks
Beneath the Georgia Coastal Plain-Regional Implications: in Studies
Related to the Charleston, South Carolina Earthquake of 1886 Tec-
tonics and Seismicity: U.S. Geological Survey Prof. Paper 1313, p. 42.

Klitgord, K.D., Popenoe, P., and Schouten, H., 1984, Florida: a Jurassic
Transform Plate Boundary: Journal of Geophysical Research, vol. 89,
no. B-9, p. 7753-7772.

Maync, W., 1950, The Foraminiferal Genus Choffatella schlumberger in
the Lower Cretaceous (Urgonean) of the Caribbean Region (Venezuela,
Cuba, Mexico, and Florida): Eclogae Geol. Helv., Lausanne, 1950, v. 42
(1949), No. 2, p. 539.

Oglesby, W. R., 1965, Folio of South Florida Basin, a Preliminary Study:
Map Series 19, Florida Geological Survey (out of print).

Palacas, J. G., Daws, T. A., and Applegate, A. V., 1981, Preliminary
Petroleum Source-Rock Assessment of Pre-Punta Gorda rocks (low-
ermost Cretaceous-Jurassic?) in South Florida: Gulf Coast Assoc.
Geol. Socs. Trans., v. 31, p. 369-376.

Company Punta
& Gorda
Fee Name Fm.

Lehigh
Acres
Fm.

Twelve
Mile
Mbr.

Brown
Dolo
Zone

APPENDIX I
SUMMARY OF WELL DATA
Net West Bone Wood
Dolo Felda Pumpkin Island River
(ft.) Mbr. Bay Fm. Fm. Fm.

T.D.
ft.

Elev. Brown Dolomite Porosity, etc.

CHARLOTTE COUNTY
B-5
HORC
Treadwell 11684 1

P-178
Gulf
Vanderbilt

P-310
Gulf
Stevens
Estate

P-373
Mobile
Babcock
Ranch

11442

12456-
2160 12365 12581

12290-
12370

11940

12290-
11528 11985 12215 12370

11930-
11290 11675 11825 12010

P-376
Mobil
Offshore
FSL-224 B. 11150

P-459
Exchange
Payson 11151

11920-
11640 11882 12000

11760-
11512 11652 830

12720 12800 NR

12495

12615 NR

55 NR

70 12164 12230 NR

12170 12220 NR

60 11960 12050 12760 NR

This well has best dolomite
seen in any onshore well with
13300 20 much vugular porosity noted,
especially in upper part of
section. Twenty feet porosity
from core and resistivity log.

Samples worthless. All tops
are questionable. No Gamma
or Sonic log in this well. No
drilling breaks. High re-
12725 22 sistivity in zone.

Porosity 7 percent from sonic
log. Some vugular porosity
noted in study of core, No
trace of oil staining noted.
Dolomite probably wopld pro-
duce because of vugs. Well
produced salt water on drill
12395 25 stem test.
Some spotty fair porosity in
upper part of Brown Dolomite
Zone. Generally poor porosity, 6
12500 55 percent or less. Sonic log use-
less because of washout.

Samples worthless. Estimate
from Gamma Ray, Sonic, and
comparison nearest wells. No
12931 21 porous dolomite.

Porosity estimated from sonic .01
approx, 8 percent. Finely cry- Co
stalline, dense. Best porosity
13432 81 at base of Interval.

-

Company Punta Lehigh
& Gorda Acres
C N ama e m Fm

P-472
Exchange
Oil & Gas
Babcock
Florida Co.11366 11780

P-475
Exchange
Oil & Gas
State Lease
2448 11175 11565

Twelve
Mile
Mbr

Brown Net
Dolo Dolo
Zone (ft.)

12050-
11940 12158 70

11930-
11852 12000 60

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

West Bone Wood
Felda Pumpkin Island River
Mbr. Bay Fm. Fm. Fm.

12360 12440 NR

12034 12120 12786 NR

T.D.
ft.

Elev. Brown Dolomite Porosty, etc.

13000 47

13232 38

COLLIER COUNTY

P-345
HORC
Gulf Coast
Realties 12803-
#24-1 11840 12462 12742 12816 0?

P-727
Tribal
Exxon
Gulf Coast
Realties 12803-
#12-4 11870 12490 12780 12872 7

13036 13072 14070 NR

14500 38

13070 13110 14150 15460 17254 40

ee ago .

DESOTO COUNTY

11260-
10745 11060 11210 11340 70

28' of 8 percent porosity and
balance 5 percent or less.

11400 11550 12190 NR

P-609
Shell
Punta
Gorda

...... =d ,,nl ,

Dolomite very fine-grained
throughout this Interval, No
commercial porosity, Sonic
log shows approx. 4 percent
porosity.

Dolomite is fine-grained, Por-
osity approx. 8-10 percent
from density log. Porosity
from sonic log approx.
10-12 percent

Much lost circulation noted
in 12810-12830 Interval. No
dolomite noted.

Gamma log misleading. This
well Is below Punta Gorda
(-11800') structure contour
and on southeast edge of
"Brown Dolomite" zone. See
text

Ir

13000 77

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

Company Punts
& Gords
Fee Name Fm.

P-679A
AMOCO
Knight

Lehigh
Acres
Fm.

Twelve
Mile
Mbr.

Brown
Dolo
Zone

Net West
Dolo Felda
(ft.) Mbr.

10280-
9916 10130 10264 10340

Pumpkin
Bay Fm.

Not present

Bone Wood
Island River
Fm. Fm.

T.D.
ft.

11655

Elev. Brown Dolomite Porosity, .

Brown Dolomite Zone very
sandy. Dolomite fine-arained,
non-porous with interbedded
light gray limestone. Sand
121 below 10,340 ft.

GLADES COUNTY

11605-
11048 11340 11540 11705

30 11815 11860 12760 NR

Information from lithology log
of Banks. Very low porosity
in Interval. Trace dead oil. No
samples through this Interval
13424 30 in sample library.

HARDEE COUNTY

10570-
10134 ? ? 10640?

HENDRY COUNTY

P-314
Sun Oil
Red Cattle 11848
P-424

Exchange
Oil & Gas
Fla. Land
& Timber 11552

12440-
12160 12378 12520

12350-
12052 12246 12364

30 10770 10835

12618 NR

10 NR

Not Pre.

11934

Redbeds 11382'. Lack of por-
osity, a 20' sampling interval,
63 and quartz sand in the Brown
Dolomite Zone make all es-
timates very questionable in
this well.

Extremely poor samples. Drill
stem test shows porosity and
12680 54 permeability In interval. Poor
suite of logs. Much of interval
probably chalk.
Approximately 6' in upper part
of zone with 8 percent por-
12494 33 osity. Very rapid decrease In
dolomite In this well. May be o>
close to eastern edge of zone. -*

P-152
Coastal
Tledke

P-62
HORC
Keen

Fee No 9 Fm. br. Zone- ---~-~-~-

Company Punta Lehigh Twelve Brown Net
A Gorda Acres Mile Dolo Dolo
Fee Name Fm. Fm Mbr. Zone (ft)
P-6585.
Mobil
Phillips 12446-
Seminole C11600 12190 12400 12500 15

P-788
Shell
Alico

P-789
Shell Oil
Consol.
Tomoka
Co.

12272-
11560 11990 12240 12328

12132-
11484 11870 12090 92

P-951
Ashland Oil
A. Duda & 12400-
Sons 11578 12078 12292 486

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

West Bone Wood
Felda Pumpkin Island River
Mbr Bay Fm. Fm. Fm.

12690 12720 13750 15100 17025 35

12515 12552 13490 14840 16000 45

22? 12374 12416 NR

58 NR

12423 44

12603 44

Elev. Brown Dolomite Porosity, etc.

Dolomite fine-gralned with
no visible porosity. Density
log shows washout, Much
chalk In Interval.

25' of fair porosity In upper
part of Interval (7-11 percent)
with some well cuttings misl.
Ing. Porosity 6 percent or less
In lower part of Interval.
Variable porosity. Approx.
one-half of Brown Dolo-
mite has porosity up to 24
percent. Samples Indicate this
Interval Is a porous chalk.

22' coarsely crystalline dolo-
mite. Balance of dolomite
has low porosity of 5 percent.
Much lost circulation material
but excellent samples.

HIGHLANDS COUNTY

B-1
HORC 10796-
Carlton 10380 10622 10758 10880 75

10990 11052 11722

Dolo 10796-10808, silty and
lacks porosity. Some vugular
porosity to 20 percent. Por-
12985 114 osity 10832-10880, variable
with some good vugular. No
sonic log. Est. 25' porous.

~ --------- -

Company Punts Lehigh Twelve Brown Net
& Gorda Acres Mile Dolo Dolo
Fee Name Fm. Fm. Mbr. Zone (ft.)

P-225
Continental
Carlton

10818-
10640 10740 10895 75?

P-862
AMOCO
Jackson 10450 10686 10792

10856-
10898 30

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

West Bone Wood
Felds Pumpkin Island River T.D.
Mbr. Say Fm, Fm, Fm. ft.

11025 11100 NR

11036 11106 11750

Elev. Brown Dolomite Porosity, etc.

No ditch or core samples. Es-
timated only from electric log
12630 88 and mud log In comparison.
with HORC Carlton well.
Micro-log shows no porosity.
No drilling break.

Approx. 8' of porosity from
neutron-density log with bal-
12625 25 ance of dolomite low porosity.
Samples confirm this.

LEE COUNTY

P-161
Humble
Kirchoff 11855 12450 12734

P-289
California
Coastal
FSL 224B. 11564 12152 12410

12830-
54

12485-
12598 103

24 NR

12748 12800 13772 NR

12877 22

Porosity to 15 percent. Some
Vugular porosity. Some slight
oil staining in upper 10' of
dolomite.

Dolomite microcrystalline to
finely crystalline. Some test
circulation material. Drill stem
13975 39 that produced water. Neutron
log and drilling time log i
indicate porosity. Samples C
comminuted. I

P-297
California
Coastal
FSL 224B. 11524 12104 12380

12445-
12560 110

NR 12600 40

Dolomite comminuted. Much
lost circulation material.
Microcrystalline to finely
crystalline. Estimated 40'
Porous.

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

Company Punts Lehigh Twelve Brown Net
& Gorda Acres Mile Dolo Dolo
Fee Name Fm. Fm. Mbr. Zone (ft.)
P-407
HORC
Lehigh
Acres 12588-
Well No. 1 11700 12250 12460 12684 70

Weo Bone Wood
Felda Pumpkin Island River T.D.
Mbr. Bay Fm. Fm. Fm. ft.

12760 12800 13660 14672 15710 58

Elev. Brown Dolomite Pooity, st

Eleven feet of porocity from
sonic log. Reet of Intervl 4-5
percent porosity. Samples
show very fine-grained
dolomite.

P-758
Exxon
City of
Ft. Myers
#16-2

12528-
11578 12112 12506 78

No porosity found In cuttlngs.
Porosety 4-6 percent from
loga nalyts

50 NR

12599 43

MANATEE COUNTY

P-236
Magnolia 10966-
Schroeder 10371 10710 10905 11038 10

Not
11115 Present

11228 70

MARQUESAS KEYS

P-275
Gulf 14620-
FSL-826Y 12860 14270 14550? 15036 400

P-284
Gulf-Cal-
Ifornia Co. 14420-
BIk 28 OCS12740 14105 14310 14640 240

14955 NR

14790 14805 NR

15475 58

15294 72

Dolomite 11020-11036 calc.,
fine-grained. Very little
porosity in dolomite.

Oil stain 14670-14680, tar oil
14754-14760. Much lost circ.
material. This zone of dolomite
has much good porosity highly
vugular.
Oil stain 14563, 14576-14578.
Variable poronity in the Brown
Dolomite, but approx. 14 per-
cent average.

I

~-----~ -~-----~ ~ ~

APPENDIX I (Con't.)
SUMMARY OF WELL DATA

Company Punts
& Gorda
Fee Name Fm.

Lehigh Twelve
Acres Mile
Fm. Mbr.

Brown
Dolo
Zone

Net West
Dolo Felda
(ft.) Mbr.

Bone
Pumpkin Island
Bay Fm. Fm.

Wood
River
Fm.

T.D.
ft.

Elev. Brown Dolomite Porositv. etc.

MONROE COUNTY

Dolomite very fine-grained,
calcitic. No porosity.

12710 14220

10162 10805

14590-
14500 14740

11090-
11045 11124

30 14885

20 11280

14910 NR

11318 NR

15455 23

Dolomite, very fine-grained,
anhydritic, calcitic, Inter-
11968 20 bedded LS, light brown,
forms, No trace of oil or
tar sand. No porosity.

PALM BEACH COUNTY

P-47
HORC
TUCSON 10757

Not
10770 10770 Present

All tops tentative, Brown dol-
omite not present This zone
11040 11075 11790 13110 13375 34 possibly 1000-11000 Inter- of
buff oolitic, millolitic
limestone. Punta Gorda and
Able member believed to be
10757-10770 anhydrite bed.

P-265
HORC
State
Lease 1004 11624

NR = Not Reached

12438-
12712 12380 12478

8 12700 12730 NR

Limestone cream to brown to
gray. Some algal plates,
miliolids, anhydrite. Dolomite
12810 34 very fine-grained with no
visible porosity. Trace tar oil
in limestone.

P-22
Gulf
FSL 373
Big Pine
Key

P-148
Sinclair
Williams

APPENDIX II
DRILL STEM TEST DATA FROM BROWN DOLOMITE ZONE

Operator & Interval
FAe Name Tested ft.

Duration of Cushion
Test (hrs,) Chokes

12184-12459

12463-12494 2

12824-12877

71 1/4

P-310
Charlotte

P-289
Lee

P-161
Lee

P-275
offshore
Monroe

P-314
HRIry

P-284
offshore
Monroe

Gulf Oil
No. 1 Stevens

Cal-Coastal
No, 1
Fla, state
224B

HORC
No. 1 Kirchoff

Gulf Oil Corp.
No. 1 state of
Fla. 826Y

Sun Oil Co.
No. 1 Red
Cattle

Gulf
California Co.
OCS BIk 28

2 1/2

Total
Recovery

500 ft. 11750 ft. salt
10/64" & 3/8" water. No show,

1000 ft, 9372 ft. salt
1/4" & 5/8" water. No show.

11700 ft. salt
water. No show.

127 bbls.
21.3 bbls, salt water.
1/4" & 1" No show.

2000 ft. salt 1100 ft. mud
water and 9000 ft.
1/4" & 5/8" salt water.

9350 ft. black
3600 ft. fresh salt water
water and 560 ft. mud.

IFBHP
FFBHP

'3027
"532

1081
4730

1273
3499

ISIBHP
FSIBHP

Chlorides
Total
Solids (Dom)

'5489
"5489

5315
5803

4732

140,000
256,600

LOST PACKER AND PRESSURE RECORDS IN HOLE

3782
5539

5514
6460

5566

6940
6940

131,000
271,000

Initial flowing bottom hole pressure.
Final flowing bottom hole pressure.
Initial shut-In bottom hole pressure,
Final shut-in bottom hole pressure.

Permit
r.nmntu

14642-14702 5 1/3

12475-12680 1 1/2

14409-14508

YY~

) SCIENCE LIRARY I 3 1262 04707 0882

FLORIDA DEPARTMENT OF NATURAL RESOURCES A 3

BUREAU OF GEOLOGY
FLORIDA GEOLOGICAL SURVEY
903 WEST TENNESSEE STREET SCzIEiCE
TALLAHASSEE, FLORIDA 32304-7795 LIBRARY

Walter Schmidt, Chief
Peter M. Dobbins, Admin. Asst. Alison Lewis, Librarian
Jessie Hawkins, Custodian Sandie Ray, Secretary

GEOLOGICAL INVESTIGATIONS SECTION

Thomas M. Scott, Senior Geologist/Administrator
Albert V. Applegate, Geologist Ed Lane, Geologist
Ken Campbell, Geologist Margaret Lehey, Staff Asst.
Cindy Collier, Secretary Jacqueline M. Lloyd, Geologist
Richard Howard, Laboratory Tech. John Morrill, Core Driller
Richard Johnson, Geologist Albert Phillips, Asst. Driller
Jim Jones, Draftsman Frank Rupert, Geologist
Ted Kiper, Draftsman Wei Wuchang, Research Asst.

OFFICE OF MINERAL RESOURCE INVESTIGATIONS
AND
ENVIRONMENTAL GEOLOGY SECTION

J. William Yon, Senior Geologist/Administrator
Paulette Bond, Geologist Ron Hoenstine, Geologist
Shelton Graves, Research Asst. Steve Spencer, Geologist

OIL AND GAS SECTION
L. David Curry, Administrator
Pete Parker, Engineer Scott Hoskins, Geologist
Brenda Brackin, Secretary Barbara McKamey, Secretary
Robert Caughey, Geologist David Poe, Geologist
Joan Gruber, Secretary Joan Ragland, Geologist
Don Hargrove, Staff Asst. Clay Roark, Staff Asst.
Charles Tootle, Engineer

FLRD GEOLIOWC( ICA SURflViEWY~

COPYRIGHT NOTICE
[year of publication as printed] Florida Geological Survey [source text]

The Florida Geological Survey holds all rights to the source text of
this electronic resource on behalf of the State of Florida. The
Florida Geological Survey shall be considered the copyright holder
for the text of this publication.

Under the Statutes of the State of Florida (FS 257.05; 257.105, and
377.075), the Florida Geologic Survey (Tallahassee, FL), publisher of
the Florida Geologic Survey, as a division of state government,
makes its documents public (i.e., published) and extends to the
state's official agencies and libraries, including the University of
Florida's Smathers Libraries, rights of reproduction.

The Florida Geological Survey has made its publications available to
the University of Florida, on behalf of the State University System of
Florida, for the purpose of digitization and Internet distribution.

The Florida Geological Survey reserves all rights to its publications.
All uses, excluding those made under "fair use" provisions of U.S.
copyright legislation (U.S. Code, Title 17, Section 107), are
restricted. Contact the Florida Geological Survey for additional
information and permissions.

	Title Page
	Table of Contents
	Part 1 1985 Florida petroleum production...
	Part 1 Contents
	Part 1 Abstract
	Part 1 1985 drilling activity
	Part 1 1985 geophysical exploration...
	Part 1 Recent Florida oil field...
	Part 1 References
	Part 1 Appendices
	Part II The Brown dolomite zone...
	Part II Contents
	Part II Abstract, purpose of study,...
	Part II Geochemistry
	Part II Structure
	Part II Summary
	Part II References
	Part II Appendices
	Back Matter

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