Bar-Mar Field, The Tricky Devonian: ABSTRACT

Abstract

What originated as the Fusselman play in southern Crane County developed into a 4-million-barrel oil field in the Devonian, an 8-billion-cubic-foot Clear Fork gas field, a 1-million-barrel Tubb field, and two Fusselman dry holes. The areal extent of this field has not been developed and is not fully known because of the large amount of acreage held by production and controlled by the major oil companies. The original geological interpretation suggested possible oil production in the Fusselman updip from a dry hole that recovered 25 barrels of sulfur water per hour on a drill-stem test. The porosity and permeability indicated from this drill-stem test suggested a fairly sizable reservoir at a relatively shallow depth of 5,400 feet. This information, in conjunction with sufficient dry-hole money and a fairly sizable acreage position for Crane County, encouraged the writer and his partner to drill the prospect. It took 1 month to sell the deal and 13 investors before sufficient funds were available to spud the well. The Devonian tripolitic chert contains one of the highest recoverable oil reserves in the Permian basin. This chalky reservoir is difficult to explore and develop. The number of dry holes are many, but the recoverable oil justifies the risk involved. The apparent trend in this wedge-edge, scarp, or tight rope can be noted along northern Crockett, southern Crane, and northern Pecos Counties. These fields which are productive from the Devonian appear to be related directly to the Fort Stockton High. The numerous adjustment or radial faults that are present along the flanks of this major structural feature are believed to be the cause of this oil accumulation. The many fields along this trend exhibit different modes of hydrocarbon accumulation. These fields in Devonian strata produce in re-entrants, grabens, and wedge-edges of tripolitic chert. The Bar-Mar field appears to be productive in a graben. While developing this field, several additional oil and gas pays were discovered; however, the major part of the Devonian production eluded the discoverer. Although it is always the dream of the independent End_Page 166------------------------------ to own an entire oil field, industry still needs the wildcatter and the independent to find the oil. This is exemplified further by the fact that, in order to find oil, one must drill wells. For several years it has been the writer's philosophy that the amount of oil discovered is directly proportional to the exposure or number of wells drilled, providing that the wells are drilled in oil country. The Bar-Mar field is a case in point. End_of_Article - Last_Page 167------------