Wyoming's Pinedale gas field growth surging

Original gas in place at giant Pinedale field in west-central Wyoming was 48 tcf at yearend 2006, and the as-yet undelineated field has become one of the largest in the US in terms of reserves.

By OGJ editors
HOUSTON, Apr. 23 -- Original gas in place at giant Pinedale field in west-central Wyoming was 48 tcf at yearend 2006, and the as-yet undelineated field has become one of the largest in the US in terms of reserves.

Ultra Petroleum Corp., the field's largest acreage holder, reported the status Apr. 23 at the Independent Petroleum Association of America's Oil & Gas Investment Symposium in New York City.

Pinedale operators expect ultimate recovery of 27 tcf of gas on 10-acre spacing and as much as 85% recovery on 5-acre spacing, Ultra said. Holding the largest acreage positions in the field are Ultra, Shell Oil Co., and Questar Corp.

The Cretaceous Lance interval has no need for horizontal drilling because its gross thickness averages 5,800 ft, drainage radius is limited, and sands 200-300 ft apart can't be correlated on seismic, Ultra noted. Recovery is estimated at 4 bcf/well on 5-acre spacing with returns in excess of 40% at a $7/Mcf long-term gas price, the company said.

Ultra, which now has more than 4,800 identified drillable locations, spent more than $500 million in 2006, replaced five times its production, increased production 23%, and participated in 170 wells in Wyoming. Average initial production rate was 8.8 MMcfd.

The 2007 plan is $600 million for 185 wells and 20% estimated production growth.

The planned Rockies Express pipeline, federally certified on Apr. 19, will transport 1.5 bcfd to the US Midwest and Northeast and improve already lucrative netbacks for Wyoming gas producers, Ultra said. It will go in service in first quarter 2008.

Ultra, which holds large interests in Pinedale and smaller Jonah field in the Green River basin, reported US gas production of 24.8 bcf in this year's first quarter.

With present reserves calculated on average pay sand thickness of 1,417 ft, and core analysis that shows the entire gross interval to be gas saturated, Ultra is mulling how much gas could be recovered from the 4,364 ft of Lance shales not in the pay count.

The Pinedale companies are also exploring for gas in the deeper Cretaceous Blair/Hilliard interval above 19,500 ft, where no reserves are booked and no sustained commercial production has taken place.

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