盐岩地下储气库风险评价层次分析模型及应用

国内盐矿具有埋藏浅、盐层薄、夹层多、品位低等特点,导致盐岩地下储气库建设和运营面临诸多技术风险。在盐岩地下储气库风险因子模糊综合评价基础上,建立了层状盐岩储气库破坏、油气泄漏、地表沉降的3大事故风险层次分析模型,并构建了风险因子对3大事故影响程度判断矩阵;将建立的模型用于评价江苏金坛盐岩地下储库气的运营风险状况,确定出储气库3大事故风险因子影响权重分布和风险等级。研究结果表明:(1)储气库破坏应重点控制低压运行压力、运行时间和矿柱应力状态;(2)储气库泄漏应重点控制套管靴位置、夹层结合面滑动、高压运行压力和管道阀门受损;(3)储气库地表沉降应重点控制顶板厚度、低压运行压力和运行时间;(4)储气库破坏和泄漏属中等风险水平,储气库地表沉降属高风险水平。油气储库3大事故风险因子权重分布和风险等级的确定,为盐岩地下储气库风险调控提供了理论指导。

Hierarchical analytical model of risk evaluation for underground salt rock gas storage and its application

The salt mines in China have the properties of shallower burial depth, lower thickness, multiple interlayer and lower grade, which will cause more technical risks for construction and operation of underground salt rock gas storage. Based on fuzzy comprehensive evaluation of risk factors of gas storage, the paper has established a hierarchical analytical model of risk evaluation of three risk accidents that storage destruction, gas leakage and surface settlement for salt rock gas storage. The model has been used to evaluate operation risk condition of Jintan salt rock gas storage in Jiangsu Province. The effected weights distribution and risk grade of three risk accidents have been determined. The research results indicate: (1) Lower pressure and operation time of low pressure and stress state of pillar should be controlled to avoid gas storage destruction; (2) Position of casing shoe, sliding of interlayer surfaces, high pressure and damage of pipeline valves should be controlled to avoid gas leakage; (3) The roof thickness, lower pressure and operation time of low pressure should be controlled to avoid surface settlement of gas storage; (4) Storage destruction and gas leakage belong to middle risk, while surface settlement of gas storage belongs to high risk. The effected weights distribution of three risk accidents and risk grade provide theoretical guidance for risk regulation of underground salt rock gas storage in China.