SALT DAMAGE CRITERION PROOF-OF-CONCEPT RESEARCH

DeVries, Kerry L. ; Mellegard, Kirby D. ; Callahan, Gary D.

Respec, Inc. (United States)

关键词: Natural Gas;    Compression;    Salt Deposits;    Testing;    Capacity;   

DOI  :  10.2172/818210
RP-ID  :  NONE
RP-ID  :  FC26-00NT41026
RP-ID  :  818210

美国|英语

来源: UNT Digital Library

【 摘 要 】

The purpose of this study was to conduct a field-scale application demonstrating the use of continuum damage mechanics to determine the minimum allowable operating pressure of compressed natural gas storage caverns in salt formations. A geomechanical study was performed of two natural gas storage caverns (one existing and one planned) utilizing state-of-the-art salt mechanics to assess the potential for cavern instability and collapse. The geomechanical study consisted primarily of laboratory testing, theoretical development, and analytical/numerical tasks. A total of 50 laboratory tests was performed on salt specimens to aid in the development and definition of the material model used to predict the behavior of rock salt. Material model refinement was performed that improved the predictive capability of modeling salt during damage healing, recovery of work-hardened salt, and the behavior of salt at stress states other than triaxial compression. Results of this study showed that the working gas capacity of the existing cavern could be increased by 18 percent and the planned cavern could be increased by 8 percent using the proposed method compared to a conventional stress-based method. Further refinement of the continuum damage model is recommended to account for known behavior of salt at stress conditions other than triaxial compression that is not characterized accurately by the existing model.