Perforating Assumes New And Greater Importance In Well Stimulation
Authors: Cocanower R.D. 
Published: December 2007

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This paper is to be presented at the Mechanical Engineering Aspects of Drilling Production Symposium in Fort Worth, Tex., on March 23–24, 1964, and is considered the property of Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the Journal of Petroleum Engineers or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.

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Perforating concepts have steadily changed as new knowledge of formation characteristics and new techniques of stimulation are developed. The former requirements of perforating tools have completely reversed to accommodate today's technology.

The requirements of today's perforating tools are covered to show how each affects the completion program. Case histories showing the methods used and relation of the perforating program to the stimulation program are presented to demonstrate the selection of the proper perforation for a well's condition. This paper does not attempt to deal with specific perforating devices, but rather to show the perforation requirements for a stimulation program. The selection of the many available perforating devices to meet the requirements of the stimulation program are left to the oil companies.

Introduction

The Petroleum Industry has grown from a "cut- and-try-beginning" to a highly engineered business. All phases of the drilling and production operation have become related factors in the success of a well or a field. The effect of perforations on the stimulation and completion efficiency of a well has only been recognized as a factor of major importance in the last few years.

Early concepts of perforating were in relation to control of water production. Wells were cased to total depth and a need to reopen the formation to the wellbore existed. The common theory was to shoot as many holes as possible to re-establish open hole exposure of the pay. Articles were published on required shot densities of six to 12 holes per foot and complete shattering of the cement was felt to be necessary. Selection of perforating devices was based on their ability to penetrate the casing and the formation. The larger the gun the better.

As wells were drilled deeper, well temperatures, formation hardness, pressures and heavier casing programs became factors to be considered. Operators took a closer look at the perforating devices to satisfy these new conditions. Perforating had become a factor to be considered in the well's program.

NEW IMPORTANCE OF PERFORATING

The necessity for better stimulation methods caused a closer look at the accepted perforating programs.