Expansion analyses of strategic petroleum reserve in Bayou Choctaw—revised locations

Abstract

The impacts of the expansion by three caverns on underground creep closure, surface subsidence, infrastructure, and well integrity are quantified.2 ANALYSIS MODEL2.1 Geomechanical modelSalt dome geometry: The stratigraphy near the BC salt dome is shown in Figure 1. The top layer is overburden, which1 INTRODUCTIONThe Strategic Petroleum Reserve (SPR) currently stores 727 million barrels (MMB) of crude oil at four sites located along the Gulf Coast. The existing 62 caverns are currently at full capacity. The U.S. Department of Energy (DOE) may increase the size of the reserve. The Bayou Choctaw (BC) site is the smallest SPR site with only six existing caverns and a storage capacity of 73 MMB. The site is limited in its expansion capability due to the small size of the salt dome and other commercial storage operations on the dome. The SPR may expand the site’s capacity through the development of two new caverns on existing SPR property and the acquisition of one existing cavern, for an increase of 33 MMB. Park et al. (2006) developed a three-dimensional Finite Element Method (FEM) analysis to model the caverns in the dome. The simulation was used to evaluate the structural integrity of the caverns located at the BC site which is considered a candidate for expansion. Fifteen active and nine abandoned caverns exist currently at BC, with a total cavern volume of 164 MMB. The DOE considered a plan to leach two additional caverns and convert one extant cavern within the BC salt dome for SPR use (URS 2006). This study investigates the structural integrity of the three expansion caverns and their interaction with other caverns in the dome in a manner similar to the previous analyses (Park & Ehgartner 2008) which was conducted for the first proposed locations of two new caverns (Ehgartner & Lord 2006).