A late October state lease sale in Washington produced some excellent bids, and served to swell the already considerable buzz about gas potential in the Evergreen State.

Specifically, people are excited about the Columbia River Basin in the south-central section of the state. The basin appears to contain an immense basin-center gas accumulation. This promise has been known for decades but has remained largely speculative, due to difficult and expensive drilling, years of lackluster gas prices and the absence of even the most basic infrastructure.

The stiffest challenges are drilling through and imaging beneath up to 11,000 feet of Miocene flood basalts that cap the basin's prospective heart. But the promise below tantalizes: thousands of feet of potential reservoirs in Tertiary fluvial sediments are present; thermally mature lacustrine shales exist; great structures, some of which express themselves on the surface, trend through the basin; sub-basalt intervals are overpressured; and gas is pervasive in water wells in the region.

Given today's drilling and completion technologies and understanding of basin-center geologic models, the time is ripe for a fresh evaluation. Helpfully, gas prices are strong and pipelines now cross the prospective region.

In all, bidders at the recent state sale pledged more than $4 million on some 145 tracts in Grant, Adams, Kittitas, Yakima and Benton counties in the basin. The top bid of $506 per acre, placed by Southern Energy LLC, was for surface and minerals on a 320-acre tract in Section 28-15n-24e, Grant County. The tract is in a township that neighbors EnCana Corp.'s #1-6 Anderville Farms wildcat, a rumored discovery.

Calgary-based EnCana has drilled the closely watched wildcat to a total depth of some 14,500 feet in Section 6-14n-25e, and has moved completion equipment onto the location. That equipment includes four incinerators, each capable of burning 7- to 8 million cubic feet of gas per day. Two units were on location during drilling operations, and two more were added for completion activities. The size and number of incinerators on the site have inspired many guesses about the scale of the discovery.

EnCana is also close to its projected 14,000-foot total depth at its #11-5 Anderson. The wellsite, in Section 5-11n-23e, Yakima County, lies about 20 miles southwest of the Anderville Farms location. EnCana has staked a third 14,000-foot well, the #7-24 Brown, in Section 24-16n-23e, Grant County.

Prior to EnCana's recent work, only a handful of tests penetrated the sub-basalt sediments. Shell, which is reported to have farmed into EnCana's current project, mounted a serious exploration program in the region between 1982 and 1989. It drilled six wells to between 5,604 and 17,518 feet. Most of its wildcats recorded gas shows, and two flowed gas at sustained rates during drillstem tests. Meridian also drilled a 12,584-foot well during that era.

One company making a major play today in the basin is Vancouver- and Houston-based Exxel Energy Corp., which holds more than 325,000 net acres.

"Our strategy has been to acquire acreage throughout the basin within areas identified by Ben Law, one of the world's foremost experts on basin-center gas plays," says Cliff Adams, president and chief executive. "We believe Exxel's acreage is extremely well-positioned, specifically relative to historic and recent activity." Estimates of total gas in place in the basin are as high as 400 trillion cubic feet, he notes.

Another firm with substantial holdings in the emerging play is Denver-based Delta Petroleum. The company, which holds 464,000 net acres, is making plans to spud wells on its Alpha and Beta prospects in the southern portion of the basin. At an investor conference this summer, Delta reported that the EnCana Anderville Farms well, in which it has an interest, had confirmed the geologic theory and had encountered what Delta had hoped it would encounter.

Certainly, despite the many positives of the play, its commercial potential depends on both the industry's ability to economically drill through the basalt section and the ultimate recovery of the wells. Some projections are that 14,500-foot wells may recover 5 billion cubic feet (Bcf) and cost $6 million each, and deeper wells that are completed in all prospective zones could make more than 25 Bcf and cost upward of $12 million apiece.

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