Horizontal drilling in the Austin chalk formation is leading to more oil and gas completions along the Cretaceous trend in central Louisiana.
True vertical depths of the objectives along the trend include Eocene Wilcox at 12,000 ft, Cretaceous Austin chalk at 15,000 ft, and the Cretaceous Eagle Ford-equivalent Tuscaloosa marine shale at 16,000 ft.
One recent completion is the Nelson Energy Inc., private Shreveport operator, Deshotels 13H-1 well in the North Bayou Jack field area of Avoyelles Parish. Initial potential filed with the state is 1,167 b/d of oil, 644 Mcfd of gas, and 350 b/d of water on a 24/64-in. choke, said Pryme Energy Ltd., Brisbane, which has 40% working interest.
Shut-in tubing pressure is 2,850 psi, shut-in casing pressure is 3,000 psi, and bottomhole pressure is 6,100 psi. The well is shut in pending installation of an artificial lift system.
North of the Deshotels 13H-1 well, Anadarko Petroleum Corp. has drilled the Rabalais 35-1 well to 14,438 ft true vertical depth in the Upper Austin chalk. Anadarko will kick off and drill a 7,000-ft lateral in the Austin chalk, Pryme Energy said.
Pryme Energy listed completion rates at other recent completions along the trend from Pointe Coupee Parish on the east to Vernon Parish along the Texas line (see map, OGJ, Aug. 1, 2011, p. 58):
Anadarko Lacour 43-1, Pointe Coupee, 3,000 b/d oil, 2.5 MMcfd gas, and 600 b/d water; Atinum Operating Inc. Britts Alt.-1, St. Landry, 2,184 b/d oil, 6.8 MMcfd gas, and 3,276 b/d water; Anadarko GASRS 5-1, Vernon, 1,073 b/d oil, 12.7 MMcfd gas, 5,465 b/d water; Anadarko Dominique 27-1, Avoyelles, 753 b/d oil, 1.2 MMcfd gas, 1,484 b/d water; Nelson Energy Deshotels 20-1, 600 b/d oil, 458 Mcfd gas; Anadarko GASRS 18-1, 500 b/d oil, 7 MMcfd gas, 6,672 b/d water; Anadarko GASRS 16-1, 203 b/d oil, 1.1 MMcfd gas, 259 b/d water.
The Deshotels 20-1 pilot hole intersected the Eagle Ford formation at 16,200 ft TVD and encountered an oil show. It was logged before plugback to 14,730 ft TVD for the transition to horizontal drilling of the Austin chalk.
Electric log analysis of the Eagle Ford formation in the Deshotels well indicated several hundred feet of sandy shale with 16% average porosity, Pryme Energy said.
“This compares favorably to some of the better locations for the Eagle Ford play in South Texas which exhibit porosities in the 6% to 12% range,” Pryme Energy said.