Interest grows in Mississippi's Upper Jurassic Cotton Valley trend

June 23, 1997
From East Texas, across northern Louisiana, southern Arkansas, and through central and southeastern Mississippi, the Upper Jurassic Cotton Valley Group of the Gulf Coast has long been an important source of oil and gas production. Presently, while the intensely competitive Cotton Valley reef trend boils along in East Texas, Mississippi's Cotton Valley trend is beginning to simmer.
Stephen D. Champlin
Mississippi Office Of Geology
Jackson

From East Texas, across northern Louisiana, southern Arkansas, and through central and southeastern Mississippi, the Upper Jurassic Cotton Valley Group of the Gulf Coast has long been an important source of oil and gas production.

Presently, while the intensely competitive Cotton Valley reef trend boils along in East Texas, Mississippi's Cotton Valley trend is beginning to simmer.

Several recent wildcat and new pool discoveries with initial test rates between 500 and 1,000 b/d of oil have heightened interest in the trend. The increased use of 3D seismic is allowing geologists and geophysicists to look hard at the Cotton Valley for potential prospects from both exploration and development points of view.

The primary area of interest is in a seven county area in southeastern Mississippi, consisting of Clarke, Jasper, Wayne, Jones, Covington, Smith, and northern Perry counties (Fig. 1) [69104 bytes]. Additionally, west central Mississippi and in general a wide band crossing the state from west central to southeastern Mississippi holds Cotton Valley potential at depths ranging from 8,200 ft in the northern updip portion to 20,000 ft plus downdip. This area occupies most of the Mississippi Interior Salt Basin and its northern flank.

Mississippi's first Cotton Valley oil production was established in 1958 at Soso field, located in southwestern Jasper County, east-central Mississippi. The Gulf Oil Corp. 1-ZB Soso Unit 28-7 well, in SW NE 28-10n-13w, was drilled to TD 19,040 ft. The well was completed flowing 110 b/d of 36.4° gravity oil with 2% BS&W on a 10/64 in. choke with 300 psi flowing tubing pressure from perforations at 15,247-256 ft.2

The known Cotton Valley producing reservoirs are fluvial-deltaic to near-shore marine clastic sand reservoirs generally found on salt related structures. On the northeastern flank of the trend, however, in the northern Clarke County area, structure at several small fields is primarily caused by draping of sediments over Paleozoic basement features updip of the Louann salt pinchout.

Through yearend 1996, 48 fields had been found in Mississippi which have produced oil and gas from the Cotton Valley (Fig. 2) [41136 bytes]. Of those, 37 or 77% were found to be productive from other formations, primarily the Lower Cretaceous and deeper Upper Jurassic formations such as the Smackover. This stacking of potential pay zones helps make Cotton Valley wildcat prospects very attractive. Cumulative production from the Cotton Valley in Mississippi as of yearend 1995 exceeded 97.8 million bbl of oil and 119.3 bcf of gas.4

Discoveries since 1990

The following is a chronological list consisting of most of the Cotton Valley discoveries in Mississippi since 1990. General information on the discovery wells and field cumulative oil and gas production data is reviewed.

Tallahoma Creek

Tallahoma Creek field was discovered Dec. 12, 1990, with completion of the Norcen Explorer Inc. 1 Ad- rine T. Moffett, in 22-8n-12w, Jones County, TD 17,020 ft.

The Upper Cotton Valley 16,200 ft oil sand flowed 968 b/d of oil, 700 Mcfd of gas, and no water, through perforations at 16,199-212 ft with 634 psi of flowing tubing pressure on an adjustable choke. Gravity of the crude was 44.4°. The zone had reported average permeability and porosity of 62 md and 14%.

The 16,570 ft Lower Cotton Valley oil sand flowed 150 b/d of oil with no gas or water reported through, perforations at 16,567-634 ft. Gravity of the crude was 33.2°. The average reported permeability and porosity were 57 md and 11%.3

The trapping mechanism for Tallahoma Creek field is simple anticlinal closure, possibly a result of deep salt movement. Development drilling on 160 acre spacing has resulted in a total of three completions in the 16,200 ft Upper Cotton Valley oil reservoir and a single completion in the 16,570 ft Lower Cotton Valley oil reservoir. As of yearend 1996, cumulative production from the Cotton Valley sands is 743,976 bbl of oil, 429,876 Mcf of gas, and 11,242 bbl of water.6

Peachtree Creek

Peachtree Creek field was discovered in April 1993 at the Germany Operating Co. 1 Rudder 29-4. It flowed 204 b/d of oil. The well, located in Clarke County, was drilled to a total depth of 9,700 ft and casing run to 9,603 ft. Production was gauged from perforations at 9,221-26, 9,232-40 and 9246-54 ft, on a 17/64-in. choke with FTP of 60-80 psi. Multiple oil sands were logged between 8,455-9,336 ft.7

Development drilling has resulted in a total of two producing wells with cumulative production as of yearend 1996 being 249,662 bbl of oil and 9,173 Mcf of gas.6 Structural closure is created by the draping of sediment over Paleozoic basement features, updip of the Louann salt pinchout.

Crawford Creek

Crawford Creek field, in Wayne County, southeastern Mississippi, was discovered in 1976. Oil and gas production has come primarily from the Hosston with a minor amount from the Sligo. The hydrocarbons are trapped in sandstone reservoirs on a deep, faulted salt structure.

In March 1994 Jack L. Phillips completed the 1 Patterson 28-7 well as a new oil pool discovery in a Cotton Valley sandstone. Located in 28-7n-7w, the well was drilled to TD 16,125 ft and 51/2 in. casing was set at 16,102 ft (Fig. 3).1 The well flowed 1,160 b/d of 48° gravity oil and 1,124 Mcfd of gas with 2,748 psi FTP on a 13/64 in. choke, from perforations at 15,008-040 ft measured depth.8 Porosity for the producing interval was reported to be 16-22%, and the original bottom hole pressure was 7,180 psi.4

During January 1995, the 1 Patterson 28-7 averaged 581 b/d of oil, 388 Mcfd of gas, and no water.5 Subsequent development drilling has resulted in a total of four Cotton Valley oil pool completions on 160 acre spacing.

In November 1996, the Mississippi Oil and Gas Board's monthly production report showed one of the Cotton Valley completions had been reclassified as producing from a second reservoir, the Cotton Valley "A" oil pool.6 Exhibits on file with the board indicate that there are up to 13 different Upper and Lower Cotton Valley sands which may be oil productive. As of yearend 1996, cumulative production for the Cotton Valley was 1,018,015 bbl of oil, 731,845 Mcf of gas, and 171,624 bbl of water.6

Jack Phillips staked a 16,400 ft Jurassic Norphlet test in May 1997 just south of the 1 Patterson 28-7.

Maynor Creek

In February 1995 PetroCorp Inc., completed its 1 Scott well in Wayne County as a Cotton Valley field discovery. The new field is approximately five miles north of Crawford Creek field. Located in 33-8n-7w, the well was drilled and cased to TD 15,890 ft. PetroCorp officially completed in a single Cotton Valley zone, but the Southeastern Oil Review reported that two Cotton Valley zones were tested at a combined rate of 1,700 b/d of oil.

Perforations from 13,718-747 ft flowed 942 b/d of 44.5° gravity oil through a 15/64 in. choke with 1,116 psi FTP and 500 psi casing pressure. A second set of perforations at 14,155-165 ft flowed 758 b/d of 51.8° gravity oil and 1,583 Mcfd of gas through a 15/64 in. choke with FTP of 2,168 psi and casing pressure of 500 psi.9

Development drilling on 160 acre spacing has resulted in a total of three producing wells and the identification of additional productive reservoirs. By December 1996, four Cotton Valley zones and one Hosston zone had been designated productive.6 As of yearend 1996, cumulative production from the Cotton Valley is 484,913 bbl of oil and 199,004 Mcf of gas from three completions. Additionally, 137,735 bbl of oil and 10,014 Mcf of gas has been produced from a well completed in the Hosston.6 The trapping mechanism for the field is believed to be similar to that at Crawford Creek field, a deep faulted salt structure.

Tiger field

Tiger field was discovered in 1971 and as of yearend 1995 had produced 1,016,610 bbl of oil and 3,994,675 Mcf of gas from the Hosston.

Apache Corp. established Cotton Valley production at Tiger field in late 1996 with the 1 Reeder 4-12, in 4-5n-10w, Perry County. The well was drilled to a TD of 15,816 ft and casing run. Perforations in Cotton Valley at 15,353-364, 15,370-389, and 15,398-412 ft flowed 1,615 Mcfd of gas, 473 b/d of condensate, and 151 b/d of water through a 20/64 in. choke with 998 psi FTP and 575 psi CP.11 Apache recently announced plans for two development locations offsetting the new pool discovery.12

More recent activity

A recently drilled well at North Wausau field in western Wayne County is a new pool discovery in Jurassic Norphlet sand.

TransTexas Gas drilled the 1 A. Foote Estate, in 20-8n-9w, to TD 15,262 ft. It flowed 12,400 Mcfd of gas, 440 b/d of oil, and 150 b/d of water through perforations at 14,889-14,915 ft in Norphlet, with 4,900 psi FTP on a 23/64 in. choke. In addition to the Norphlet pay, it is reported that a 60 ft Cotton Valley zone was tested flowing about 1 MMcfd of gas before fracturing.10

In March 1997, Spooner Petroleum Co. completed a Cotton Valley development well at Stringer field in Jasper County. The 1 Viersen 30-9, in 30-1n-11e, was drilled to a TD of 15,268 ft and pipe was set at TD. The well flowed 612 b/d of oil with no water from perforations in the Middle Cotton Valley at 14,940-957 ft. FTP was 460 psi through a 22/64 in. choke.13 This well was completed 29 years after the initial discovery of Cotton Valley production at the field.

Five wildcat Cotton Valley tests were on the active list as of mid-April. Three are permitted locations, and two are shut-in for testing. TDs range from 8,700 to 19,200 ft. Eight development locations are reported in four fields. Three of these are permitted locations, three are listed as currently drilling, and two are reported as shut-in, apparently waiting on tests.14

Conclusion

With the generally better prices for oil and gas the last year, the potentially high production rates, the possibility of stacked productive zones, improved seismic technology like 3D, recent significant discoveries such as Crawford Creek and Maynor Creek fields and successful development projects like at Stringer field, the Cotton Valley trend in Mississippi is one of the more important and lucrative trends for exploration and development activities in Mississippi.

References

1. Crawford Creek Field Docket Exhibit File, Mississippi State Oil and Gas Board.

2. Mississippi Geological Society, 1957, Mesozoic-Paleozoic producing areas of Mississippi and Alabama, Vol. I.

3. Mississippi Oil & Gas Production Annual Report 1991, Mississippi State Oil and Gas Board, 1992.

4. Mississippi Oil & Gas Production Annual Report 1995, Mississippi State Oil and Gas Board, 1996.

5. Mississippi Oil & Gas Production Report, January monthly report, 1995, Mississippi State Oil and Gas Board.

6. Mississippi Oil & Gas Production Report, monthly reports January through December, 1996, Mississippi State Oil and Gas Board.

7. Southeastern Oil Review, Apr. 12, 1993.

8. Southeastern Oil Review, Mar. 14, 1994.

9. Southeastern Oil Review, Feb. 27, 1995.

10. Southeastern Oil Review, Jan. 6, 1997.

11. Southeastern Oil Review, Feb. 3, 1997.

12. Southeastern Oil Review, Mar. 3, 1997.

13. Southeastern Oil Review, Mar. 17, 1997.

14. Southeastern Oil Review, Apr. 14, 1997.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.