Driven by superior economics and improved technology, drilling action in Louisiana's Austin chalk trend is heating.
Operators are pressing a variety of development projects to support increasing production from the rapidly maturing oil and gas play
Although discoveries were slow in coming during the early years of the play -- in part because of a lack of infrastructure -- the rate of successful wells has been increasing.
That improving success rate in turn has been boosting operators' hopes, swelling their ranks, and continually lowering finding costs -- all of which combines to enhance the exploration and development attractiveness of the Louisiana chalk.
Another attraction is the high BTU content of chalk gas, which commands premium prices but necessitates a major processing infrastructure.
During just the past 6 months, companies have committed more than $125 million for infrastructure development projects to accommodate anticipated production increases, according to one operator's estimates, which may be conservative.
But based on the level of current and anticipated activity, considerably more infrastructure will be needed to keep pace with Louisiana chalk E&D action, judged to be one of the hottest onshore plays in the U.S. today.
About Louisiana chalk
The Louisiana portion of the Texas-Louisiana Cretaceous trend cuts a wide and narrow diagonal swath several hundred miles from the Texas border at the Sabine River east across Louisiana, tracking under Lake Pontchartrain and into the Gulf of Mexico (OGJ, Apr. 9, p. 15).
Chalk wells are typically drilled as vertical holes with single and dual horizontal laterals on 1,920-acre spacing. But there are larger spacing units found near Baton Rouge and smaller units closer to the Sabine River.
So far, chalk production in Louisiana is found in only about the westernmost 100-150 miles of the trend, generally from Avoyelles Parish on the east to the Texas state line on the west.
Several years ago, there was virtually no significant chalk production to in Louisiana. But that is changing because of the increasing positive role technology is playing -- including measurement-while-drilling (MWD) technologies, improved mud and bit programs, and use of 2D and 3D seismic -- and because operators now have a lot more well histories in their hip pockets when staking and drilling new chalk locations than was the case previously.
"Technology is now allowing it to become a commercial reservoir," said Bryan Humphries, Oxy USA Inc.'s Louisiana and Mississippi asset team leader.
How play evolved
Most drilling and development action is found in and around Brookeland field, which extends across the Texas-Louisiana border, and in and near North Bayou Jack, North Hadden, Masters Creek, Burr Ferry, and South Burr Ferry fields.
Geographically, operators also refer to the active trend areas as South Brookeland, Leesville, Masters Creek, St. Landry, Baton Rouge, and Livingston.
With the exception of Brookeland field, discovered in 1983, and North Bayou Jack, which was developed vertically, all of the fields that are seeing most action now were found in just about the last 5 years.
The current play's roots trace to Cliffs Oil & Gas Co., Houston, which drilled the reentry horizontal 1-A Martin in Avoyelles Parish in East-Central Louisiana in 1991 that tested almost 2,600 b/d of oil and 1.5 MMcfd of gas from a single 2,135-ft lateral. The well, drilled to 15,339 ft TVD and 17,103 ft measured depth, opened North Bayou Jack field in Avoyelles and St. Landry parishes to horizontal development.
In July 1992, Sonat Exploration Co., a unit of Sonat inc., Birmingham, Ala., drilled the single-lateral 1-C Sonat Minerals, which opened North Hadden field in western Vernon Parish.
Union Pacific Resources Group Inc. (UPR), Fort Worth, with partner Helmerich & Payne Inc., Tulsa, opened LaCour field with 1 O.B. LaCour et al. in Point Coupee Parish in February 1994 . The well holds the distinction of being the first dual-lateral horizontal drilled in the Louisiana chalk. It started off strong, testing more than 1,600 b/d of …