GRI-02-0242 Geomechanical Analysis of Pressure Limits for Thin Bedded Salt Caverns

Abstract

Several organizations have developed guidance documents for designing and operating storage salt caverns (CSA 1993; API 1994; IOGCC 1995). Few of these efforts, however, have focused on some of the critical technical aspects related to cavern development in thin, heterogeneous, bedded salt formations. There are three basic geomechanical processes that limit maximum and minimum pressures in a bedded salt cavern. These are: The tensile fracturing pressure for the salt material and interbedded non-salt materials; The formation stresses, induced by cavern pressure decline or increase, at which bedding plane slip might be induced between heterogeneous material layers;� The minimum cavern pressure that might induce roof instability or excessive closure. The goals of this project have been to investigate and summarize for operators each of these limiting factors, and to present guidelines and analysis tools to determine minimum and maximum pressure limits for bedded salt caverns in a variety of structural settings.