Florida Geological Survey


 SUNNILAND FIELD

 In September 1943, Humble Oil and Refining
Company discovered Sunniland field in Collier
County, Florida (Figure 1); this was the first
commercial oil discovered in Florida. The
discovery well was the Humble Oil and Refining
Company Gulf Coast Realties number 1 (permit
42) located in Section 29, Township 48 South,
Range 30 East. The well was completed in an
open hole interval between -11,568 and
-11,592 feet MSL. Initial production was 97
barrels of 260 A.P.I. gravity oil and 425 barrels of
saltwater per day by pumping.
 The well was drilled on a prospect outlined by
magnetic, gravity, seismic, and core data.
Production in the field is from various porous
zones in rudistid mounds in the upper 60 feet of
the formation. Mitchell-Tapping (1985) described
the producing horizon as consisting of leached
rudist and algal particles together with pellets
and foraminifers. Mitchell-Tapping's (1985)
study of Sunniland, Bear Island, and Forty Mile
Bend fields concluded that the depositional
environment of these fields was that of a tidal
shoal with a landward (east-northeast) mud-flat
area and a seaward (west-southwest) shallow-
water back-reef area. The structure map (Figure
22) for the Sunniland field shows a northwest-
southeast trending dome that formed as these
rudistid beds grew with slowly-rising sea level
during the Lower Cretaceous. The dome is
about four miles long and two miles wide with
closure of about 40 feet.
 Twenty-six producing wells and ten dry holes
 have been drilled at Sunniland field. Sunniland
 field has been producing oil for almost 50 years;
 increased saltwater production has forced
 abandonment of many of the old Sunniland wells.
 Eighteen of the producers had been abandoned
 by the end of 1989. Of the remaining eight
 producers, five were shut-in during 1988 and
 1989. The other three produced intermittently
 during 1988 and 1989 and were all also shut-in
 as of December 1989 (Appendix 3). Oil


production totaled 18,445,000 barrels at the end
of December 1989 (Appendix 2).


 SEMINOLE FIELD

 The discovery well for the Seminole field was
the Weiner-Oleum Corporation well number 12-1
(permit 662) in Section 12, Township 48 South,
Range 32 East, Hendry County (Figure 1). The
well was completed in the -11,379 to -11,384 foot
MSL interval of the Sunniland Formation on
November 14, 1973. Initial production was 26
barrels of 25.40 A.P.I. gravity oil and eight barrels
of saltwater per day. This three-well oil field was
abandoned in 1978 after producing a total of
85,000 barrels of oil (Appendix 2).


 BEAR ISLAND FIELD

 Bear Island field was discovered on December
5, 1972, with the completion of the Exxon Gulf
Coast Realties number 2-4 well (permit 563) in
Section 2, Township 49 South, Range 30 East
(Figure 23). The field is located about two miles
southeast of Sunniland field (Figure 1). The
discovery well pumped 132 barrels of 260 A.P.I.
gravity oil and 545 barrels of saltwater per day
from perforations between -11,558 and -11,564
feet MSL in Sunniland carbonates.
 The structure map of Bear Island field (Figure
 23) indicates a northwest-southeast trending
 dome about 4.5 miles long and 2.5 miles wide
 with a closure of about 55 feet. Mitchell-Tapping
 (1985) found this field to have the same faunal
 assemblage as Sunniland field; his conclusion
 concerning the general depositional environment
 is listed above in the description of Sunniland
 field. Despite the generally similar origin,
 Mitchell-Tapping (1985) found Bear Island field to
 be lithologically different than Sunniland field.
 Most of the Sunniland Formation at Bear Island
 field is dolomitized and is more leached than at
 Sunniland field. Anhydrite and some secondary
 dolomitization has reduced the effective