G. Alan Petzet
Exploration Editor
East Texas' sprawling Brookeland field, where nearly every well has single or multiple horizontal legs producing from fractured Cretaceous Austin chalk, continues to grow at a respectable rate.
The field, with about 155 surface wellbores drilled covers an as yet unevenly developed 800 sq miles in parts of five counties in the piney woods of East Texas - Jasper, Newton, Sabine, San Augustine, and Tyler-and has just been extended into Southwest Louisiana.
The Louisiana completion extends the length of the east-west producing trend to about 65 miles, and operators say the downdip limits have not been defined.
The reservoir grades from oil and casinghead gas in the north and west to retrograde condensate further south and east, and gas/condensate completions exceeded oil completions during 1994. Gas-oil ratios vary widely across the field.
Operators reported completion of 123 horizontal wellbores during 1.994 to Petroleum Information Corp., tying Brookeland with California's supergiant Midway-Sunset field in the number of completions reported during the calendar year.
Including vertical and horizontal wellbores, the 123 Brookeland completions accounted for nearly 1.7 million ft of hole. Average measured depth was 13,766 ft.
An independent operator discovered Brookeland field in 1983 at a marginal vertical completion on a farmout from ARCO Oil & Gas Co., but intensive development did not begin until 1990.
The field has a long development period ahead. Ultimate recovery could reach 100 million bbl of oil equivalent, and there is some thought the field might produce that volume in oil and condensate alone.
PRODUCTION GROWING
Brookeland's cumulative production since 1990, when the first horizontal well was drilled, is placed at about 12 million bbl of oil and condensate and 85 bcf of gas from the chalk.
Some 68 of the 123 completions reported in 1994 made gas and condensate, PI noted.
Sonat Exploration Co., Houston, became the field's largest production operator last year with about 40% of the field's gross daily production.
The company's production averages 6,000 b/d of oil and condensate and 48 MMcfd of gas from 36 operated wells.
Projected well lives in the southern central portion of the field are easily 6-7 years, and production is holding up well, said Bryan Simmons of Tyler, Sonat Austin chalk business unit manager.
Union Pacific Resources Co., Fort Worth, said its April 1995 Brookeland production averaged 5,000 b/d of oil and 30 MMcfd of gas.
Texaco Exploration & Production Inc. operates 24 producing wells-22 of which have dual legs-averaging 2,000 b/d of oil and condensate and 15 MMcfd of gas.
LOUISIANA EXTENSION
Several operators have had mechanical difficulties completing Austin chalk wells in various Louisiana parishes until recently (OGJ, Dec. 19,1994, p. 140).
Sonat in late April completed a Vernon Parish well that extended Brookeland field production 5 miles east into Louisiana from Sabine and Newton counties, Tex.
Sonat's 1-28 Temple flowed a combined 7.2 MMcfd of gas with 1,500 b/d of oil from two laterals with a combined displacement of 8,080 ft in the chalk. Operators said the record combined displacement for dual laterals stands at 10,00011,000 ft.
Louisiana likely will establish a different field name for the well, but Sonat considers it part of the Brookeland field Austin chalk trend.
Sonat has 250,000 acres of minerals and leasehold in Louisiana on trend with Brookeland field.
Chalk fracture mechanism and other reservoir parameters appear favorable on Sonat's Louisiana acreage, Simmons said.
Sonat hopes to have the well on sustained production in June through a pipeline being built westward to a gas processing plant in which it has an interest in the Texas part of the field.
OXY USA Inc., Houston, is drilling another chalk horizontal well in the Masters Creek field area of Rapides Parish near where its I Monroe A flowed 6.6 MMcfd of gas with 2,162 b/d of 48 gravity condensate late last year. Masters Creek is 60 miles east of Sonat's Brookeland extension.
Explorers don't seem much interested in the Austin chalk trend between Brookeland and giant Giddings field to the southwest. They say the chalk thins and resistivities are much lower there.
THE FUTURE
Brookeland field reserves and production seem destined to grow much further as high volume, multileg horizontal wells are completed in more of the field's interior.
Nuevo Energy Co., Houston, and Texaco Exploration and Production Inc. said it may require as many as 20 locations to fully develop 33,000 acres adjacent to the companies' recently completed 1 H Temple Inland A-41 well in Jasper County.
The dual lateral well flowed 9.25 MMcfd of gas and 984 b/d of oil through a 48/64 in. choke with 1,720 psi FTP from 6,973 ft of horizontal hole in Austin chalk. The well is about 1 1/2 miles southeast of Nuevo's Tonahill well, which produced 47,000 bbl and 476 MMcf in its first 3 months' production.
The well is the first on 58,000 acres dedicated to a Nuevo-Texaco joint venture, of which 33,000 acres are contiguous to the Temple-Inland well.
UPRC and Sonat are each keeping three rigs busy this spring. Sonat plans to participate in 19 wells in 1995 at a cost of $19 million. It said drilling costs have fallen dramatically, mainly as a result of utilizing wells with opposing laterals.
UPRC was the field's busiest operator of new wells during 1994 with 40 laterals reported, PI noted. The company, which operated 19 wells in the field last year, plans to drill 23 this year and 20/year or more in 1996-97.
UPRC and Sonat started up a 50 MMcfd gas processing plant in April 1994 that is running at capacity. They plan to double capacity later this year.
Texaco and Torch Operating Co. are drilling a Sabine County dual lateral well that is the third in a five well program for the combine.
An Abilene, Tex., independent, Dale W. Morris, is attempting to extend the field into southeastern Angelina County at the 1-H Angelina USA ' It is a projected dual lateral chalk well 9 miles north of the field's nearest producer in Tyler County.
Other operators active in the Texas part of Brookeland field include Tana Oil & Gas Corp., Corpus Christi, Bexco Operating, College Station, Tex., and Sonerra Resources, Nacogdoches, Tex.
Copyright 1995 Oil & Gas Journal. All Rights Reserved.
