The detailed study of oil sands in the laboratory yields considerable information relating to their capacity for storing fluids, the movement of fluids through them, and selective retention.
Effective pore size is related to grain size distribution in a particular manner for each sand. The effects of capillarity and gravity vary with pore size and nature of the wall. Some pore walls selectively adsorb tarry constituents; others do not. Permeability usually varies with time.
This paper is a brief summary of 5 years’ work on oil-bearing sands and limestones in the laboratory of the United States Geological Survey.
Figures & Tables
The AAPG volumes of Structure of Typical American Oil Fields preceed this book, which was written as a sequel to those, and at first conceived as a third volume of the earlier work. This book is designed to review, modify and, if possible, clarify ideas with regard to the fundamental concepts of oil geology, utilizing, for this purpose, the material presented in the two earlier data-based volumes. To conform to the original standard set for it, this book has been kept relatively free from factual data and has been compiled rather as a summation, based upon the best available evidence, of present knowledge of the science. This volume does not include a discussion of the technique of field or laboratory geology, but does include papers divided into 7 parts: History; Origin and evolution of petroleum; Migration and accumulation of petroleum; Relations of petroleum accumulation to structure; Porosity, permeability, compaction; Oil-field waters; and Subsurface temperature gradients.