Part 4 - Berg - Hughes Center

According to Roberts and Lock (1988), in 1982 a well in Sligo field, Boissier Parish
was perforated through the intervals 4,360 to 4,366 ft and 4,442 to 4,446 ft with initial
production of 68 bbls of 41.8 API gravity oil per day through a 14/64 choke. Between
September 1982 and June 1987, total production was 38,951 bbls of oil and 28,846 Mcf
casing head gas. Only 900 bbls were produced in the first six months of 1987. Of the two
zones perforated, the upper is in miliolid packstone with up to 5 md permeability and
16% porosity (moldic and intercrystalline). The lower is dolomitized and has
permeabilities of up to 15 md and porosities of up to 15%. The Rodessa also produces
from a light-gray, porous, chalky, pseudo-oolitic, fossiliferous limestone with a few
streaks of white, fine-grained sandstone in the western half of the field. This reservoir is
about 25 ft thick, has a porosity of 20%, and produces from an area of approximately
19,000 acres.
Other Rodessa reservoirs are productive in northern Louisiana (Frizzel, 1987). Depth
to the top of pay ranges from 3,700 to 6,000 ft. Net pay is generally 10 to 30 ft thick.
Reservoir porosity ranges from 10 to 26% and permeability from 10 to 650 md.
Hydrocarbons produced are typically 34º to 41º API gravity oil, condensate, and gas.
Ferry Lake Anhydrite
Producing Parishes
Caddo, De Soto, Bossier
The Lower Cretaceous Ferry Lake Anhydrite is one of the most distinctive,
widespread sedimentary units within the Gulf Coastal Plain. The formation extends from
east Texas across southern Arkansas, northern Louisiana, central Mississippi, and
southern Alabama, and to south Florida where it has been correlated with anhydrite beds
of the Punta Gorda Formation (Forgotson, 1957). The approximately 250 foot thick Ferry
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