Horizontal technology helps spark Louisiana's Austin chalk trend. (petroleum and gas drilling)

A handful of companies paced by some of the most active operators in the U.S. are pressing the limits of horizontal technology to ramp up Cretaceous Austin chalk exploration and development (E&D) across Louisiana.

Most of the Louisiana chalk action so far has been confined to a few horizontal wells in two western parishes. Early results have been spotty, compared with the mounting record of Austin chalk successes in Texas.

But successes in Louisiana include an extension of the Austin chalk play in Brookeland field of East Texas. Horizontal activity also has opened chalk pay to development at a half dozen other fields, most notably at North Haddens and Burr Ferry fields in Vernon Parish and the Masters Creek area of Rapides Parish.

Companies find applications in Louisiana for lessons learned drilling horizontal wells to produce chalk intervals in Texas in Giddings, Pearsall, and Brookeland fields (see map, OGJ, Dec. 11, 1995, p. 40). Continuing advances in horizontal well technology are helping operants deal with deeper, hotter reservoirs in more complex geological settings that typify the chalk in Louisiana.

In mid-April, data compiled by Petroleum-Information Corp. (PI) showed 23 active chalk horizontal wellsites in Louisiana, 21 of which were permitted in the previous 5 months. That included permitted wellsites where either drilling was in progress or operator/had yet to file completion reports. PI data showed operators each year from, 1992-95 at most drilled only three or four horizontal Austin chalk well in Louisiana.

How 1996 is shaping up

Of reported 1996 activity, Sonat Exploration Co., Birmingham, Ala., was operating at 12 sites, the most among companies working in the Louisiana chalk.

Sonat had a four rig development drilling program under way in western Vernon Parish, filling in an area between two earlier discoveries that extended Brookeland field across the Texas-Louisiana state line. The company also had three rigs drilling horizontal chalk wells in the Texas portion of Brookeland.

Chesapeake Energy Corp., Oklahoma City, had four rigs active at Louisiana chalk drillsites in Louisiana, including three in Masters Creek. One of the rigs in Masters Creek was drilling the second lateral in the 1 Laddie James 7 well, Chesapeake's first in the field. Earlier, in the James well's first lateral, the company logged its best well test in its 6 years of existence.

Meantime, aggressive leasing at locations all along the Louisiana chalk trend has garnered hundreds of prospective drillsites. Sonat, Chesapeake, Union Pacific Resources Group Inc. (UPR), Fort Worth, and Oxy U.S.A. Inc., Tulsa, plan to step up drilling in the trend this year, and some substantial production gains are expected.

In addition, UPR and Amoco Production Co. in March announced formation of a joint venture (JV) that plans to use 3D seismic data in pursuit of the chalk in a 400,000 acre area in East Central Louisiana.

In all, 1996 is shaping up as a breakthrough year for Austin chalk E&D in Louisiana.

Improved technology

Since its introduction to the Austin chalk in Texas in the late 1980s, horizontal well technology has …