Research On Stability Evaluation Of Salt Cavern Underground Gas Storage

In recent years, domestic and foreign salt cavern gas storage destabilizing incidents have occurred, resulting in leakage of gas storage, gas storage destruction, ground subsidence or collapse and other accidents, causing huge economic losses and environmental damage. C hina’s salt mine has thin salt, shallow, more mezzanine and other features, which makes the construction of salt cavern gas storage more difficult, the risk of operating quickly increased, especially in urgent need of in-depth study and breakthrough in cavern stability management. Therefore, taking jintan gas storage as an object, this paper further studied the gas storage stab ility evaluation and management, and the main research contents and achievements of the paper are as follows:(1) Drawing on domestic and foreign factors and technology of gas storage stability evaluation, this paper have obtained the main cause of instability of salt cavern underground gas storage by using FLAC3 D simulation. Analyzed the main factors affecting of the storage stability, considered the Jiangsu Jintan rock salt gas storage as the energy engineering, using the combining method of analytic hierarchy process and fuzzy comprehensive evaluation method to calculate the stability level of each layer by layer, the paper obtained the quantitative evaluation of the consequences of the stability and instability of underground salt cavern gas storage, and the corresponding evaluation grade. Because of the scoring model structured according to the results of numerical simulation combined with the relevant research, the model has significantly reduced the error caused by the subjective evaluation of the subjective evaluation.(2) The paper has made use of the fuzzy analytic hierarchy process to quantitatively evaluate the gas storage instability impact, gas reservoir seepage, gas storage library destruction and surface subsidence or collapse, and forecasted the consequences of instability of gas storage, and put forward the measures to reduce or avoid risks according to the different evaluation results(3) According to the established stability evaluation methods and evaluation criteria of salt cavern underground gas storage, based on C# programming technology, a set of targeted “salt cavern underground gas storage library stability evaluation software” has been developed, in order to improve the efficiency and the accuracy of the evaluation. Insure that we can eliminate or reduce all kinds of risk factors to the acceptable range, and the gas storage can keep running safely and s moothly until the storage turns into instability.This paper obtained the gas storage stability final score 78.84 points by simulation calculating Jintan rock salt energy gas storage stability. When the gas storage was assumed minimum operating pressure less than 3 MPa, the maximum operating pressure less than 8 MPa, the score became 53.55 points and at this time predict the consequences of the gas storage instability. The evaluation results are realistic and consistent with the relevant salt cavern gas storage stability evaluation results, providing practical reference for the underground gas storage operation and management.