Log Map, New Type of Subsurface Map

Abstract

This paper describes what is believed to be a new type of subsurface map. It is essentially a structure-contour map, on which variations in the lithological succession of a formation, member, or smaller unit are depicted by a series of electric or other logs. The name log is conveniently applied to this type of map. Since an attempt is made to provide a three-dimensional picture on a two-dimensional surface, limitations are placed on the clarity and completeness of the map by the thickness of the selected formation interval, the well spacing and the scales used. With the addition of appropriate data the map is an extremely useful tool in the analysis of subsurface geology, as a location plan, and as a reservoir map upon which the development of reservoirs can be planned and followed.