Such attention is directed at unconventional plays these days, but frontier areas prospective for conventional oil and gas still exist.

One small firm has assembled a commanding position in a western Washington State basin that contains sandstone reservoirs, large structures and basic pipeline infrastructure.

Comet Ridge Ltd. is an Australian-listed company with a Denver-based U.S. subsidiary, Comet Ridge USA Inc. During the course of several years and some 160 transactions, it accumulated 475,000 acres of leases and options in Grays Harbor Basin, west of Olympia in Grays Harbor and Pacific counties.

Grays Harbor is an overlooked basin that contains all the parameters needed to establish production, says Andy Lydyard, president and chief executive of the U.S. unit. The basin, tucked between the Cascades and the coast, holds some 12,000 feet of sediments. It’s one of a series of structural sub-basins that lie along a 200-mile-long trend between Eugene, Oregon, and Seattle. Production has been established along this trend at Mist Field, in northwestern Oregon.

Within Comet Ridge’s area of interest, 108 wells have been drilled during the past 80 years, but just 16 reached depths below 3,000 feet. Of that group, three penetrated the section below 7,000 feet. The last well drilled in the basin was a 1985 Amoco test.

“We see evidence of multiple reservoirs, traps and sources in Grays Harbor Basin,” says Lydyard. Potential reservoirs are Tertiary sandstones that attain hundreds of feet in thickness and have porosities up to 30%.

Additionally, existing seismic data and surface maps point to numerous thrusted anticlinal traps. “We’ve compiled a database of all available information, dating back to the early 1900s,” says Pat Jackson, vice president of exploration. That includes 450 miles of 2-D seismic data acquired in the 1980s, during the last surge of activity.

One of the basin’s most compelling aspects is its large number of shows. “We have everything from oil and gas shows in mud, to core shows, to blow-outs.” Indeed, blow-outs were documented on two wells, and 29 other tests recorded strong shows or actual gas flows. Most shows were concentrated in Miocene deltaic sands in the Astoria formation and Oligocene turbidite sands in the Lincoln Creek formation.

“All of this evidence suggests there is actively generating source rock in the basin, and that’s previously been one of the questions about this area,” says Jackson. Deep marine shales in the Lincoln Creek and Eocene Cowlitz and Crescent formations are the most likely source rocks.

The Comet Ridge executives think today’s technology—seismic, drilling techniques and completion strategies—combined with current prices will make production of Grays Harbor gas economic. It has identified 39 leads in the basin that could contain, on an unrisked basis, resources of 1.7 trillion cubic feet.

This year, the company plans to acquire 11 square miles of 3-D seismic and 60 miles of 2-D on two key prospects. Each contains potentials in the range of 100- to 120 billion cubic feet of gas equivalent. One prospect is updip of a well that recorded 1,100 feet of continuous gas shows on mud logs. The 3-D program will attempt to confirm closure. At the other, Comet Ridge will shoot 2-D seismic to firm several surface and subsurface leads.

A drilling program will follow the seismic. Comet Ridge’s operating subsidiary in Washington, St. Helens Energy LLC, is currently permitting five locations, and plans to spud its first well later in the year.

Helpfully, a natural gas pipeline already runs through the basin. The Cascade Natural Gas line carries gas from Rocky Mountain and Canadian sources to consumers along Washington’s coast. Gas demand is strong and growing in this part of the country, and the commodity trades at a premium to Henry Hub prices.

“If Grays Harbor works, it will be a significant new province. We’re very excited,” says Lydyard.

In addition to its exploratory Washington acreage, Comet Ridge holds more than 8,500 acres in Florence Field in Fremont County, Colorado. It has shot an eight-square-mile 3-D survey over the field, Colorado’s oldest, and plans to drill at least three wells there this year. Total depths will be between 3,000 and 4,700 feet, to Pierre and deeper.