Chapter 20 - Hazards of Gas Storage Fields

Abstract

The chapter summarizes the hazards of gas storage fields. The problems can be grouped into three areas: problems related to the natural pathways for lateral and vertical gas migration, problems related to man-made pathways for vertical gas migration, and problems related to carcinogenic chemicals present in the natural gas. One must consider the following in designing underground gas storage facilities: the presence of faults and fractured zones, lithology and structure of the overlying formations, and breakdown of cement and the seals that block the vertical migration of fluids and gases in the well bores, and their annular space. In California, gas is transported from out-of-state through pipelines. The gas is then stored in several underground reservoirs until needed by consumers. These storage fields operate under large pressure fluctuations, dictated by seasonal variations in the demand for natural gas. Today, the risks of injury from fire and/or explosions have increased because a greater percentage of the land is now covered, not permitting the gas to escape into the atmosphere. It is necessary to monitor and evaluate the soil gas content, the rate of gas migration to the surface, oil and gas production from the underlying oil fields, older improperly abandoned oil wells, and all oil field operations that produce fractures and free gas, and predict possible environmental complications associated with these operations. Different case histories of gas migration problem are also discussed in this chapter.