Seeking New Oil in Old Fields

Wildcatters are drilling again in the Eastern U.S.

Edwin Drake launched the petroleum age in 1859, when he drilled 69½ ft. into the ground along Oil Creek, near Titusville, Pa., and hit history's first oil gusher. Now, after more than a half-century of decline, the oil-and gasfields of Pennsylvania, Ohio, Kentucky and New York are gurgling anew. The fields are part of what geologists call the Eastern Overthrust Belt, a corridor of convoluted limestone, sand and shale that stretches 1,200 miles along the slopes of America's Appalachian Mountains, from the Adirondacks to Alabama.

Though the Eastern Overthrust produced more than half the oil consumed by the U.S. at the turn of the century, the region's appeal diminished shortly thereafter, when wildcatters hit richer fields in Texas, California, Louisiana and Oklahoma. Yet with oil now selling for upwards of $38 per bbl., drillers are returning to the Eastern Overthrust for a fresh, and more thorough, look at what their predecessors might have left behind.

In Somerset County, Pa., southeast of Pittsburgh, Standard Oil of Indiana has already sunk three dozen natural gas wells. In the Crab Orchard Mountains of Cumberland County, Tenn., Ladd Petroleum has struck oil and gas at depths of up to 4,000 ft., and expects to keep searching for the next five years before the area's potential is firmly established. In Kentucky, Tennessee and Georgia, Atlantic Richfield and Gulf are planning to spend up to $26 million over the same period to drill on some 1.2 million leased acres.

As with the Western Overthrust Belt, which stretches through the Intermountain West from Canada to the Rio Grande, the Eastern strip takes its name from the geological folding and overlapping that occur when mountain ranges are forced upward through sedimentary rock. Some oilmen estimate that such formations in the Western Overthrust states could hold as much as 13 billion bbl. of crude, or more than two-thirds of the amount that might be contained in the Alaskan North Slope.

Most energy experts doubt that the Eastern Overthrust's reserves will prove comparable to those of the Western belt. The U.S. Geological Survey believes that the region's potential could be as much as 1.5 billion bbl. of oil. Says Michel T. Halbouty, a leading Houston geologist and independent operator: "I believe a concerted exploration effort in that area will probably yield huge reserves."

The region's biggest payoff will probably come in natural gas. Drillers are already having considerable success in tracking down uptapped pockets of the precious fuel. In 1978 the Columbia Gas Transmission Corp. struck gas in Mineral County, W. Va., with a well that gushed 10 million cu. ft. of the fuel per day. A year later, the company tapped into a second natural gas gusher producing 8.8 million cu. ft. daily. Such start-up production levels are comparable to major wells in gas-rich Louisiana and Oklahoma.