A New Method for Creating Gas Storage Caverns: Design and Feasibility of Using Acid to Dissolve Carbonate Rock

Castle, James W.¹, David A. Bruce¹, Scott E. Brame¹, Ronald W. Falta¹, Lawrence C. Murdoch¹, and Donald A. Brooks^2
1 Clemson University, Clemson, SC 
² DB Consulting, Millington, NJ

We are proposing a new method for creating gas-storage capacity in carbonate rocks. The design and feasibility of this technology, which involves creating caverns by dissolving carbonate rock formations using acid, were analyzed based on process design, geological factors, and preliminary economic analysis. The method involves drilling one or more wells, pumping acid into the formation, and then removing and treating the waste fluid.

Aspects of the dissolution process that were examined include: weight and volume of rock to be dissolved; gas storage pressure, temperature, and volume at depth; rock solubility; and acid costs. Hydrochloric acid was determined to be the best acid to use because of low cost, high acid solubility, fast reaction rates, and highly soluble products. Our analysis indicates that the new method can be applied most advantageously to carbonate formations deeper than 4000 feet, with limestone at depths between 6000 and 9000 feet preferred. In order to identify areas that are potentially suitable for the new method, a large amount of data from carbonate formations was compiled for six states. Based on regional mapping using Geographic Information Systems (GIS) software, large areas of West Virginia, Pennsylvania, and New York were identified as potentially suitable for developing gas storage caverns by dissolving carbonate rock formations. Smaller areas that may be suitable were identified in Indiana, Ohio, and Kentucky. Preliminary economic analysis, including cost comparison with other gas storage methods, provided favorable results for potential application of the new method.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004