The Wasson field is near the central part of the Staked Plains or "Llano Estacado," in southern Yoakum and northwestern Gaines counties. At present it occupies a triangular-shaped area 15 miles long and 14 miles wide containing approximately 59,000 acres or 93 square miles. It is still in an active state of development and has been defined at only a few points by dry holes.

Geologically, the field lies on the extended axis of the Central Basin platform, but appears to be separated from it by a trough in northern Gaines County. For the purpose of this paper the structural-stratigraphic feature under discussion will be referred to as part of North Basin platform.

Two major axes, one trending N. 60° W., the other N. 30° E., combine with several minor parallel axes to form a compound structure. The combined effect of the structural elements gives the whole the appearance of a terraced platform which has been tilted to the northeast by post-Permian movement.

The problem of stratigraphy is typical of West Texas in that massive, porous dolomites with fewer clastics form the highs and grade basinward into thicker sections of interbedded dolomite and anhydrite containing more clastic materials.

End_Page 933------------------------------

The section penetrated by wells consists of: Recent, Tertiary, Cretaceous, Triassic, and Permian deposits. The reservoir is in porous dolomite 300 to 600 feet below the top of the San Andres. Detailed examination and recording of the well-cuttings show the body of the reservoir to have a reef-like cross section which may be accounted for by (1) chemical deposition on a marine high, or (2) reef-growth with attendant chemical deposition.

The combination of Permian structure and stratigraphy appears to have controlled the permeability, porosity, and the accumulation of fluids. Later folding modified the position of these fluids somewhat. For the field as a whole there is no direct relationship between the present structural elevation and the ability to produce oil.

The discovery well, Honolulu Oil Corporation and Davidson Drilling Company No. 1 Bennett, was drilled into oil on September 28, 1935. Development has been continuous since that time and 16,388,981 barrels of oil had been recovered from the field on September 1, 1940.

End_of_Article - Last_Page 934------------