Deep Gas Well Completion Practices
Authors: Lindsey H.E. 
Published: December 2007

This paper was prepared for the International Deep Drilling 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.

The data used for this discussion on deep gas well completions has been taken from experience in equipping over 112 wells in fields in the Delaware Basin, Anadarko Basin and a few in the Jurassic trend area of Northwestern Florida and Southern Alabama. Depths of these wells are in the 16,000–30,000 ft. range.

While much has been written about deep well completions, this paper will discuss and review the early designs and show an evolution of completion practice to the present time. Typical casing, liner practice to the present time. Typical casing, liner and tubing programs will be illustrated and explained. Some ways will be shown to simplify completion design and to make a better selection of tubulars.

Tubing and bottom-hole equipment must be designed so that there will be no seal movement during the flowing life of the well and yet have safe upward travel during well stimulation. 0 accomplish this purpose, simplified equations and illustrative solutions will be given in the paper for the engineer himself to design tubing slack-off and spacing for stimulation and future production.

Some of the work, particularly the section and graphs on flowing temperature and its effect, we believe appears here for the first time.

Introduction

The major considerations in gas well completion design are:

large enough tubulars to perform stimulation work, underbalanced perforating and to permit adequate production capacity, subsurface production equipment to hold high pressures and prohibit leakage, protection from the pressures and prohibit leakage, protection from the effects of hostile environment, means of performing safe workover operations on the well performing safe workover operations on the well without damaging the reservoir and resistance to or relief from stresses during treating and flowing such as piston effect, helical buckling, ballooning and temperature.

GAS WELL COMPLETION DESIGN TUBING SELECTION

The first step in the selection of bottom-hole equipment and tubulars is to determine the effect of pressure and temperature and the resultant stresses. The movement of the tubing should be calculated accurately, (preferably by the design engineer and not by computer); so he will know exactly what factors cause government, buckling, etc. The best criteria to use is the condition during stimulation exactly at the moment of "balling out" - after the tubing has been cooled down by the treatment fluid.