CLIFT, SIGRID J., and STEPHEN E. LAUBACH, Bureau of Economic Geology, The University of Texas at Austin,F. E. ABEGG, KERBY S. ASLESEN, T. MATTHEW LAROCHE, ROD G. STANLEY, Chevron USA Production Company
A test of these methods was carried out on naturally fractured Wolfcamp A2 sandstone cores from Chevron's Mitchell 1B No. 7 and University 29 No. 1 wells, located in the Pakenham (Wolfcamp) field in the Val Verde Basin Results show that, as predicted from microfracture analyses, open fractures are lined and bridged by synkinematic quartz cement, and filled (closed) fractures are occluded by postkinematic ankerite, barite, and other minerals. Matrix postkinematic cement volumes accurately predict the location of filled fractures. These results show that microstructural analysis is a promising approach for diagnosing fracture openness and for helping to assess fracture permeability in reservoirs.
AAPG Search and Discovery Article #90936©1998 AAPG Southwest Section Meeting, Wichita Falls, Texas