American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
Natural gas can be stored in many ways but when geologically feasible, salt cavern construction is usually the method of choice. Salt caverns permit the highest rate of gas delivery, provide a secure for of storage, permit full product recovery, and usually require the least cost for construction. This paper presents a review of cavern paper presents a review of cavern design parameters.
Three ingredients are necessary to develop a solution mined storage caverns: a thick salt formation, a supply of fresh (or low salinity) water, and a means of brine disposal. The fundamental principle of development is to simply expose the salt in a drilled hole, inject fresh water into the hole, allow time for dissolution, and withdraw the resulting brine from the hole, As the salt dissolves, the hole enlarges into the form of a cavern.
In actual practice, the procedure for cavern development is somewhat more complex. In the case of a thick salt mass, a single leaching well is usually sufficient as shown in Figure 1. Thinner salt may require two fracture connected wells as shown in Figure 2. In either case, each well should have a fully cemented string of casing extending from surface into the salt. Leaching is conducted by injecting the light fresh water down a tubing string with sufficient pressure to force the heavier brine up the other tubing string. Concentric tubing strings must be used in the single well configuration but separate strings can be run when dual wells are available. In either case, the annular region enclosed by the cemented casing must be filled with a light nonleaching and noncorrosive fluid such as oil or propane.
