Factors Influencing The Performance Of Gas Storage Reservoirs Developed In Aquifers
Authors: Gober W.H. 
Published: December 2007

This paper is to be presented at the Gas Technology Symposium of the Society of Petroleum Engineers of AIME, to be held in liberal, Kans., November 18–19, 1965, and is considered the property of the 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 Technology or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of there 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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Abstract
The performance of depleted oil or gas fields converted to gas storage can be predicted from previous production history. In the case of an aquifer developed for gas storage, no previous records are available on which to base performance predictions.
Aquifer boundary conditions, overpressure, cyclic two-phase flow of gas and water and other factors influence the performance of aquifers developed for gas storage. Conventional engineering and operating practices must be modified to predict and control aquifer behavior.
The factors presented are the ones most common to the gas storage Begment of the industry. The comparison of the factors influencing aquifer performance to their counterpart in the producing fields is left to the reader.

Introduction
The natural gas transmission and distribution segments of the petroleum business must continually find new ways to lower the cost of fuel to the consumer. This is necessary if the natural gas business is to remain competitive with other fuels. One of the major ways in which the natural gas industry can remain competitive is to discover and implement new methods of improving the load factor of their system. A high load factor simply means that the system is operating at full system capacity at all times. Since the major portion of the natural gas delivered to market is used for space heating, it is readily seen that the requirements will be greater in the winter time than in the summer time.
In order to increase the operating efficiency of the system, and thereby lower the cost of gas to the consumer, most companies have turned to some form of underground storage. The most advantageous location for underground storage facilities is in the proximity of the major markets. In areas where depleted oil or gas fields were available, these reservoirs have been repressured and converted into gas storage. In another instance, an abandoned coal mine near Denver, Colorado has been converted to gas storage use. In areas lacking depleted fields or other means for storing gas, it has become necessary to discover and develop other types of storage. As a result gas storage in aquifers was born.

BOUNDARY CONDITIONS
An aquifer is defined by Webster as a waterbearing bed or stratum of earth, gravel or porous stone.