The Application And Limitation Of Deep Drill Stem Testing
Authors: Zecchi Paul J. , Scott Basil J. 
Published: December 2007

This paper was prepared for the Deep Drilling and Production Symposium of the Society of Petroleum Engineers of AIME, to be held in Amarillo, Tex., Sept. 11–12, 1972. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This paper presents a review of the techniques currently utilized in deep well drill stem testing. The procedures for both open hole and cased hole testing are presented with particular emphasis on the problems and existing solutions to these problems. Data from actual drill stem tests in the Anadarko Basin of Texas and Oklahoma and the Delaware Basin of West Texas are reviewed.
The trend for ultra deep wells, those below 20,000 feet, has been increasing during the past few years. The entire drilling and service industry has been challenged to provide the equipment and expertise to drill the provide the equipment and expertise to drill the wells, evaluate the formations, and provide mechanical equipment for producing them. Formation evaluation of these deep zones by a drill stem test has been successful, but much planning and innovation was necessary. High planning and innovation was necessary. High pressure and high temperature are two factors pressure and high temperature are two factors that present unusual problems. Particular attention must be paid to drill pipe and tubular goods in all deep drill stem tests. Very high mud weights also have received considerable attention in planning a deep drill stem test.
A case is presented in this paper to show that all deep wells can be safely evaluated with a drill stem test. Planning is the key word in obtaining a successful drill stem test. Problems and solutions associated with deep drill stem testing are also presented.

Introduction
The drill stem test has been accepted since the 1920's as the best and most economical means of evaluating a formation. The equipment utilized in the first drill stem tests was very simple and used with the prime purpose of obtaining a sample of reservoir purpose of obtaining a sample of reservoir fluid. Subsequently, pressure recorders were included in the test string to check the mechanical functioning of the drill stem test tools. Later, new drill stem test tools and evaluation techniques were introduced to enable the industry to obtain many reservoir parameters from the test data. parameters from the test data. As the industry drilled deeper, drill stem testing kept abreast with technology to evaluate these deeper zones. Testing procedures and techniques were improved, equipment procedures and techniques were improved, equipment was sophisticated and personnel were trained to be more familiar with any problems or conditions that arose.
Today, new depths are again being reached, and once again drill stem testing is keeping pace. Recent developments in technology have pace. Recent developments in technology have provided the equipment and material by which provided the equipment and material by which wells to 30,000 feet and deeper may be tested.