Tech Transfer Track

Online Course, Finding O&G Information on The Internet

Competitive Analysis Technologies (CAT) now offers an online, interactive, self-paced training course about Finding Oil and Gas Information on the Internet. The course resulted from five years of industry training seminars. CAT has taken the lessons learned from these seminars and developed nine modules, including topics such as: Finding Oil & Gas Experts at Universities, Research Institutes and Associations and Improve Your Search Techniques—Find Just the Answers. The online format allows busy professionals to sharpen their "information searching" skills and interaction with the instructor further refines those skills. Those successfully completing the course will receive CAT's CD outlining 4,700 upstream Internet resources.

Cost is $239. AAPG members can receive a membership discount and CEU credits. Visit CAT's website for further course information (www.
catsites.com/seminar.html#
oilgas).

Unocal Corp., using Expro International Group PLC's StimTube™ technology, treated a basically non-producing Gulf of Mexico gas well, turning it into a well producing more than 4 MMscfd.
StimTube is an oxidizer-based tool for reservoir stimulation which, when detonated, can generate large volumes of high-pressure gas, as much as 20,000 psi at the reservoir face. These high-pressure gas pulses are effective in perforation breakdown, fracture initiation and elimination of near wellbore damage.

StimTube can be run through tubing or on slickline to stimulate existing perforations and eliminate the need for additional stimulation techniques.

Unocal's well, located in the Brazos A105 block, had been initially completed with 300 ft of open perforations in the low permeability Big Hum "D" formation. Production rates and pressures had steadily decreased over time until it was unable to produce against a system pressure of 500 psi. A decision was made to isolate the bottom 138 feet of perforations due to water and sand production and leave 162 feet of perforations open to flow. While this successfully eliminated water and sand production, stable flow could not be initiated. Wellhead pressure would build readily to 1500 psi when shut-in, but when brought online would drop to below line pressure in a matter of minutes.

Based on analysis of original log data and Expro simulations, three 15-feet assemblies of StimTube were used to treat a 75-ft interval. Upon first firing, an immediate pressure increase of 90 psi was observed at the surface. After the second firing, an additional increase of 20 psi was recorded. This same effect was observed following the third firing. The well was brought online with a stabilized flow rate of 4 MMscfd. Payout occurred within less than 10 days. Unocal foresees other applications for the technology.

See July 23rd Expro press release (www.exprogroup.com/), subsequently reported in Oil and Gas Journal (Sep 15, 2003, p. 75).

GTI has been evaluating high-powered lasers for well drilling and completion since 1997. Fundamental research completed in 1999 established that state-of-the-art lasers had enough power to cut rock 10 to 100 times faster than rotary drills. A second phase of research in 2000 and 2001 explored more detailed issues such as laser cutting-energy assessment, rock removal capabilities of pulsed vs. continuous-wave lasers, and the effects of lasing rock in the presence of water. Funding for this second phase was provided by GTI, the U.S. Department of Energy (DOE), PDVSA and Halliburton Energy Services.

DOE recently released funding for the next stage that will establish the technical feasibility of using laser tools to drill natural gas wells and conduct engineering studies leading to prototype tool development. DOE has earmarked about $2.1 million of funding, supplemented by about $1 million in GTI cofunding. GTI has established an exclusive working relationship with IPG Photonics, Inc. applying its high-power, fiber-optic laser technology to well construction and completion tasks. In a parallel effort, GTI recently began a proof of concept project with a major E&P industry partner for a downhole, fiber-optic laser system for perforation of casing.

For more information, contact explorationproduction@
gastechnology.org.

The Interstate Oil and Gas Compact Commission's (IOGCC) recently released annual survey established that a significant portion of the increase in U.S. onshore natural gas production in 2002 came from stripper wells. Production from marginal gas wells, which IOGCC defines as wells producing less than 60 Mcfd, represented 10% of the gas produced onshore in the lower 48 states and accounted for 43% of the overall rise in natural gas production. A large percentage of the many coalbed methane wells now being developed would fall in this stripper gas well category. With respect to the number of stripper natural gas wells, the leading states in descending order are Pennsylvania, West Virginia, Ohio and Texas.

Production from the nation's more than 400,000 stripper (< 10 Bopd) oil wells was up slightly to 324 million barrels in 2002, averaging 2.2 Bopd/well. Production from these wells represented 30% of the oil produced onshore in the lower 48 states. With respect to the number of stripper oil wells, the leading states in descending order areTexas, Oklahoma, Kansas and Ohio.

Contact IOGCC (phone 405-525-3556 or www.iogcc.state.ok.us/) to order the report.

Petroleum Abstracts (PA) subscribers now can access the PA Discovery database through a website search interface provided by AAPG/Datapages. PA covers the worldwide scientific and technical literature and patents related to oil and gas exploration and production.

Underbalanced drilling (UBD) can be a critical component in adding incremental reserves, especially in combination with other technologies. Key benefits from UBD are improved reservoir access, reduced skin damage and better ability to evaluate the reservoir while drilling. This article presents four case histories (two international, two domestic) showing the benefits of UBD. Highlights of the two domestic cases follow.

The Hatter's Pond Field in Alabama is an 18,000-ft gas condensate reservoir producing from the Norphlet dolomite and Smackover Sandstone. Discovered in 1974, it has been a prolific field, producing more than 210 Bcf and 50 million barrels condensate. By the late 1990s pressure had declined from original of 9,200 psi to 2,700 psi. In 1999 the 18 producing wells averaged 100-400 Bcpd and 3-6 MMcfd. With lower reservoir pressure recent wells drilled with conventional mud systems had experienced losses to the formation. The Norphlet 10-11#4 was drilled underbalanced using natural gas misted with diesel. After completion it produced 16 MMcfd and 800 Bcpd and had produced 11 Bcf of gas by February 2002. Comparing decline curves with other conventionally-drilled wells, this well's performance exceeds other wells by several times, and that with lower pressure than wells drilled earlier.

In the Wayne Field in Williston Basin, producing from the Mission Canyon fractured carbonate, GeoResources drilled the first horizontal well overbalanced. Although the lateral achieved the planned 1800-ft length, data indicated length was at a maximum with overbalanced drilling techniques. The next four horizontal wells were drilled nearbalanced or underbalanced. The most immediate benefit was improved access. UBD techniques were primarily responsible for doubling well lengths compared to the first well. In the four following wells, an incremental 8,000 ft of lateral length is attributed to using lateral techniques. The four underbalanced wells cost more to drill, but paid out nearly twice as fast and are expected to deliver twice the reserves and net present value.

Excerpted from "Does Underbalanced Drilling Really Add Reserves?" Drilling Contractor, July/August 2003, pp. 26-29.