气藏型地下储气库地质体注采运行风险分级与管控

Risk classification and control of gas-storage geological body of gas reservoir type during injection,production and operation

地下储气库(以下简称储气库)是由储气地质体、储气库井、地面设施组成的储气系统,其中储气地质体是必不可少的重要组成部分。目前气藏型储气地质体在完整性评价方面中研究较多,对风险分析与风险等级划分尚属空白。为此,在分析气藏型储气构造密封性失效的风险的基础上,完善了气藏型储气地质体的概念,然后对储气构造的危害因素进行识别、分析、等级划分。研究结果表明:(1)气藏型储气地质体是由储气构造和监测构造组成的地下三维空间内地层、构造、流体等的集合体;(2)气藏型储气地质体的风险评价技术系列由储气构造密封性失效、储气空间体积减少两项风险分析技术构成;(3)气藏型储气地质体风险等级从低到高可划分为Ⅰ级、Ⅱ级、Ⅲ级,分别对应可接受、可容忍、不可接受三类风险。结论认为,气藏型储气地质体风险分析与分级体系的建立,弥补了储气库风险分析缺少地质体的缺陷,为气藏型储气库安全运行管理提供了重要支撑,有力地保障了“天然气银行”的正常运行。

Underground gas storage(hereinafter referred to as UGS)is a gas storage system composed of gas-storage geological body,UGS well and surface facility,among which,gas-storage geological body is an essential part.So far,more researches have been carried out on the integrity evaluation of gas-storage geological body of gas reservoir type,but its risk analysis and risk classification are still blank.In this paper,the concept of gas-storage geological body of gas reservoir type is improved by analyzing the risk of sealing failure of gas storage structure of gas reservoir type.Then,the hazard factors of gas storage structure are identified,analyzed and classified.And the following research results are obtained.First,gas-storage geological body of gas reservoir type is an aggregate of formation,structure and fluid in the underground three-dimensional space,which is composed of gas storage structure and monitoring structure.Second,risk assessment technology series for gas-storage geological body of gas reservoir type consist of two risk analysis technologies,i.e.,the sealing failure of gas reservoir structure and the reduction of gas storage volume.Third,the risks of gas-storage geological body of gas reservoir types can be divided into LevelⅠ,ⅡandⅢfrom low to high,which correspond to three types of risks,namely acceptable risk,tolerable risk and unacceptable risk.In conclusion,the risk analysis of gas-storage geological body of gas reservoir type and the establishment of classification system makes up for the lack of geological body in UGS risk analysis,so as to provide an important support for the safe operation and management of gas reservoir type UGS and powerfully ensure the normal operation of"natural gas bank".