ARMA 09-076 Evaluating the Present in-situ Stress-State for the Richton, MS, Strategic Petroleum Reserve Site using Geomechanical Analyses

摘要

The United States Strategic Petroleum Reserve has selected the Richton Mississippi (MS) salt dome as an oil storage site suitable to increase its current capacity to one billion barrels. In order to confirm that the Richton MS site is adequate for storage of oil deep underground, an evaluation of the present in-situ stress-state was investigated using numerical techniques involving large scale geomechanical analyses. Several Finite Element Analysis (FEA) models were constructed to approximate the complex three-dimensional Richton salt dome formation and surrounding rock in two-dimensions. These FEA models elucidated the significance of a parental salt bed which feeds the Richton salt diapir formation. Using complex creep material models to treat the near-field Richton salt diapir and elastic material models to simulate the surrounding media, the structural response of the Richton salt dome was interrogated for several geometric configurations and initial conditions. Results of these FEA simulations showed a significant difference in vertical, horizontal, and von Mises in-situ stress states, which provide valuable information as to where the salt caverns might best be located within the dome to maximize structural integrity, etc.