Application of Sedimentary Directional Features and Scalar Properties to Hydrocarbon Exploration

Abstract

Ripple marks, cross-bedding, and groove casts are examples of directional features of sediments. Systematic downcurrent variations in grain size or mineral composition are examples of scalar properties. Although directional features normally are considered to be the tools of the surface geologist, these features also can be used by the subsurface geologist by means of the oriented core and the dipmeter. Recent literature abounds with reports of new types of scalar properties. Directional features and scalar properties of sediments are used to determine paleocurrent direction. The integration of paleocurrent data with environmental information yields a paleogeographic map, from which prediction of favorable areas for wildcat exploration and the exploitation of wildcat discoveries can be made. A directional features ^rarr paleocurrent direction + depositional environment = paleogeographic map study of the early Desmoinesian Hartshorne Formation in the Arkoma basin, Oklahoma, indicates that the productive Hartshorne Sandstone in the discovery gas well of the South Pine Hollow field of Pittsburg County, Oklahoma, is probably a deltaic distributary channel sandstone with a NE-SW alignment. This type of study could have been used to exploit the discovery well; the information needed to reach the same conclusion by subsurface geology was not available until some time after the initial discovery.