L00310 Movement of Underground Water in Contact with Natural Gas

This research was initiated to bring together the knowledge required to predict water movement in gas storage operations. The goal was to develop calculation procedures, which could be utilized directly by engineers in charge of the operation of storage fields. Engineering studies of water drive occurring in gas storage reservoirs pointed out the need for more definite procedures of calculation because of the cyclic nature of the storage operation.

The first year of the project was devoted to developing equations and procedures to ascertain, analyze and interpret the nature and the extent of water drive for various geometric models. Solutions to the equations and procedures for calculation were developed during the first year. Digital computing techniques were developed to permit the handling of the large number of calculations required by the nature of the pressure cycles. During the second year, field data were collected and analyzed for several storage and production operations. The field data were employed to compare predicted performance with observed behavior. These calculations required refinements and extensions of the equations developed during the first year. The organization of the entire material pertaining to the mathematical treatment of water drive gas reservoirs, applications of filed data, discussion of results and general conclusions were undertaken during the third and concluding year of the project.

This monograph covers the full range from the calculation procedures for practicing engineers to the complex mathematical developments required in deriving the relationships used and the computer programs for machine computations. This monograph is prepared for three groups: (1) the reservoir or field engineers for gas storage and producing operations, (2) computing center personnel in gas companies who are likely to become involved in water movement calculations, and (3) research engineers working on reservoir phenomena, who desire to find in one volume a summary of pertinent unsteady-state flow equations and their solutions.