Advancements Through 15 Years of Fracturing

Abstract

Abstract This paper summarizes the growth and development of hydraulic fracturing from the time of its commercial introduction 15 years ago to the present. During this interval more than 400,000 treatments have been performed in areas representing nearly every section of the Free World. Statistical data are presented showing trends in growth, treatment size, propping-agent concentration, injection rates and other features. Some of the more important developments are discussed. Techniques have varied from the routine-type application to the highly technical treatment designed for specific well formations. Designed treatments probably will become more prominent in the future, with efforts directed toward refining and improving present techniques. Basic research on entirely new concepts will continue. Introduction In Oct., 1948, Stanolind Oil and Gas Co. (now Pan American Petroleum Corp.) announced its hydraulic process to help increase well productivity, culminating several years of extensive laboratory and field study. The first commercial fracturing job was performed in March, 1949, over 15 years ago. Since that date more than 400,000 treatments have been applied to wells located in practically every part of the Free World where oil and gas are found. In addition, untold numbers of wells behind the Iron Curtain have been treated. Many fields are in existence today because of these techniques-without them, producing horizons very probably would have been by-passed as either barren or commercially non-productive. An estimated 10 per cent of all recoverable reserves in North America can be attributed to this type of stimulation. During this 1 1/2-decade interval, marked advancements have been made in materials, equipment and techniques of application. Jobs have progressed from the usually small-volume type operation to that often employing large volumes of fluid and materials injected with equipment utilizing several thousand hydraulic horsepower, Techniques have varied from the routine, everyday-type application to the highly technical treatment designed for a specific section of producing formation in which completion is to be made. It would be impossible in one short presentation to cover the entire subject of hydraulic fracturing and the many changes that have occurred since its conception. However, this article will review some of the more important developments. Trends A better understanding of what has happened may be obtained by viewing some of the trends that have occurred during this period. Fig. 1 presents a growth history of average treatment volume and propping-agent concentration in the United States. Initially, jobs consisted of 750 to 1,000 gal of a gelled hydrocarbon (usually kerosene or crude oil) containing about 1/2 lb of sand/gal. Early in 1952, the use of refined and crude oils began to gain momentum; by late 1952, a large portion of total fracture treatments performed were of that type. These cheaper fluids permitted greater volumes for equal or less cost, and the volume of fluid per fracturing treatment has maintained almost a constant rise since 1952. JPT P. 760ˆ