The Copley oil pool of Lewis and Gilmer counties, West Virginia, is an illustration of synclinal accumulation of oil in sands which carry no water. Oil occurs in the deepest part of the basin, at the foot of a descending axis, being almost surrounded by gas in the anticlines on either side and along the higher synclinal axis northeastward. Southwestward the pool is terminated by poor sand rather than by changed structural conditions.

Oil production began by the completion of the Copley gusher in 1900, and still continues with a prospect that the pool will have ten more years of life. Gas production on a large scale began about 1909 and still continues, although the rock pressure, which originally was 550 pounds, has declined to 65 pounds.

Production is mainly from the Gordon Stray, Gordon, and Fifth sands of the Catskill series of the Upper Devonian. There is little prospect of lateral extension of the pool, but there is hope of new gas production in deeper sands. Oil production is not probable in deeper sands unless it be found in the Lower Devonian and Silurian beds 7,000-10,000 feet deep.