Evaluation of Well Perforator Performance
Authors: Porter W.L. , Satterwhite B. 
Published: December 2007

Over the past 25 year a standard procedure has evolved for evaluating the performance of various perforating tools available to the oil industry. performance of various perforating tools available to the oil industry. This paper reviews the testing procedures and gives a brief explanation of the definitions and theory of well perforator performance.

Introduction

All perforators used today are tested and certified according to the API standard. The question is, "What do these test results mean in relation to my particular requirements?"

Perforating in the late 1930's and early 1940's was done with bullets. Field results from this perforating were quite varied. Several major companies conducted tests to determine the performances of the various guns under controlled conditions. With the introduction of jet perforating in 1948. much of the variance in perforator perforating in 1948. much of the variance in perforator performances was alleviated. Jet perforators were tested performances was alleviated. Jet perforators were tested on simulated targets and showed highly consistent penetrating power. Further testing indicated little change in penetrating power. Further testing indicated little change in the penetration under simulated subsurface pressure conditions.

Claims were made about the performance of the newly developed jet perforators that could not be substantiated by independent investigators testing the commercially available et perforators. Basically, the problem was that the targets and test procedures being used by the service companies and the oil companies were not standard, so no valid comparisons could be made among the many perforating tools that were available. perforating tools that were available.In 1962 a subcommittee of the Committee on Drilling and Production Practices of the API Div. of Production set out recommendations, standards. and procedures for evaluating well perforators. These recommendations and procedures were revised in 1971. Most of the perforators procedures were revised in 1971. Most of the perforators in use today have been tested and certified according to these API standards. It is imperative, however, that the users of jet perforators realize that the standards set by the API have upper and lower limits and that these certifications to the API are made by each manufacturer rather than by an API team. In addition, these API tests cannot be extrapolated directly to any given well condition because of certain rock properties, rock strengths, and borehole conditions.

This paper presents the various information given in the API certification and discusses its meaning to the users of -jet perforators. The performance factors as related to rock properties, rock strengths, and hole conditions are also discussed.

Early Evaluation

Considerable progress has been made in the development of well perforators since the original bullet-gun perforator was developed in 1927. The bazooka of World perforator was developed in 1927. The bazooka of World War II was developed into what is now known as the jet perforator or, more specifically, a lined shaped charge. Jet charges were first used for oilwell perforating in Canada in 1948. Most perforating today is perforating in Canada in 1948. Most perforating today is performed with the jet perforator; however, there is a performed with the jet perforator; however, there is a standard procedure for testing both bullet and jet perforators for comparative purposes. perforators for comparative purposes.Early evaluation of the perforators was performed by individual companies, with both Humble (now Exxon Co., U.S.A.) and Pan American (now Amoco Production Co.) taking the lead in establishing some standards for proper comparisons.

JPT

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