Review of the Completion Practices in the Wilcox Formation in South and South Central Texas

Abstract

ABSTRACT The Wilcox formation is a primary target for exploration and development of relatively low permeability tight gas reservoirs. Many operators have and will continue to drill for the Wilcox in South and South Central Texas. This formation continues to make a major economic contribution to the area's oil and gas industries. This paper will present background information on the geology of the Wilcox formation. The data presented will include lithology data derived from x-ray diffraction, and Scanning Electron Micrograph (S.E.M.) studies of whole core and/or sidewall core samples. The formation rock characteristics, such as permeability, porosity, youngs modulus, and formation water analysis are also discussed. Some of the latest completion techniques, including cementing, casing and perforating programs, are discussed in detail. Bottom hole pressure, thermal and fracture gradients are reviewed due to their important influence on completion practices. A variety of stimulation procedures have been used very successfully on the Wilcox formations. Stimulation fluid selections, volumes and even injection rates have their influences on completion practices and resultant production. Finally, the types and size proppant selected and the volumes used are presented to maximize the production and to provide an optimum completion program.