In 1976, Stephen A. Holditch joined the faculty at Texas A&M University, followed by W. John Lee in 1977. That same year, S. A. Holditch & Associates Inc. was formed as a petroleum engineering consulting company. The consulting company initially focused on reservoir and production engineering aspects of tight gas reservoirs, to include well completions and hydraulic fracturing treatment design. One unique aspect of S. A. Holditch & Associates Inc. at the time was its approach, designing the optimal fracturing treatment in the office and then going to the field to make sure the optimal treatment was actually pumped in the ground.

S. A. Holditch & Associates Inc. continued to grow, and in 1983 it became the lead technical contractor for the Gas Research Institute (GRI) in its Tight Gas Sands (TGS) research focus area. The grand objective of the GRI tight gas research was to learn how to make measurements before, during, and after a fracturing treatment so the 3D size and shape of a hydraulic fracture could be calculated in real time. The GRI TGS research project lasted approximately 10 years, involved multiple contractors, and essentially achieved its goal by developing the first versions of the technology the industry commonly applies today.

The technology used today involves detailed data collection before and during a fracturing treatment, real-time analyses of the fracturing treatment data, 3D computations of fracture shape and dimensions, microseismic analyses to evaluate fracturing treatments, and complete data integration to better understand the fracturing treatment process. These technologies and systems are being applied worldwide by virtually all service companies to improve performance from unconventional reservoirs.

In addition to the TGS project, S. A. Holditch & Associates Inc. also became involved with the GRI Gas Shales project area and the GRI Coalbed Methane project area. The engineers and geoscientists at S. A. Holditch & Associates Inc. were fortunate to do a lot of cutting-edge work and were encouraged to publish the work in appropriate technical meetings. As a result, the family of professionals who worked at one time or another at S. A. Holditch & Associates Inc. has published several thousand technical papers pertaining to unconventional gas reservoirs. The group also has worked on several SPE textbook, monograph, handbook, and reprint series volumes. A bibliography of the body of work generated by employees of S. A. Holditch & Associates Inc. is found in Case Histories of Tight Gas Reservoir Development, available as a digital document from SPE.

By 1997, S. A. Holditch & Associates Inc. had opened five offices and had more than 50 employees. The business was more and more global, and it was decided that to continue to grow, the company needed to change its business model. At the same time, Schlumberger decided that it needed to focus on the reservoirs. Instead of deciding what to recommend to its clients on a well-by-well basis, Schlumberger needed to first understand what technology is required to maximize reservoir performance, then to determine how to drill, evaluate, complete, and stimulate individual wells to optimize the reservoir performance. As it turned out, the business goals of the two organizations were compatible, and Schlumberger purchased S. A. Holditch & Associates Inc.

The purpose of this book is to document the technology allowing the industry to produce tight gas reservoirs. We highlight the contributions of the many employees at S. A. Holditch & Associates Inc. but do not limit our discussions because we want to include other important contributions to the technology. All of the information in this book can be found in the SPE literature, but it is convenient to pull it together in one place. We could not include everything, but we include enough references that the reader can find what is needed in either this book or the references.