气枪激震观测和评估人工干预地下构造应力场的研究

Re-using the underground natural gas storage reservoir (an unused natural gas reservoir which was established by the Project of Natural Gas Transmission from West to East China) and utilizing the nearby earthquake observation spot with the pressurized air gun (PAG) shock facility, large amount of natural gas can be injected into or retrieved from this reservoir, such that one can proactively intervene this underground rock stratum structure stress strain field, for subsequent observation and measurement. By scanning the reservoir with the highly stable and highly repetitive earthquake shock waves generated by the PAG, one can effectively monitor the changes of the reservoir rock stratum sound of speed, the ground elevation, the gravitational field due to the change of the amount of stored natural gas; one can also consider the influence of the reservoir rock stratum field seepage and the stress-strain field upon the distribution of sound of speed; one can establish the multi-physics model for finite element analysis (FEA) numerical simulation, evaluating both the scope and intensity of the underground rock stratum structural stress-strain field change due to the proactive human intervention. The significance of completion of this project is twofold. In the short term, it will enable the accumulation of the safety data for nearby Urumqi. In the long run, it will enable the accumulation of both data and experience, and the exploration of both engineering principles and practicalities by the proactive human intervention upon the underground rock stratum structure, which will ultimately help to reduce or even eliminate the disastrous damages caused by the near ground earthquakes.

利用西气东输工程建立的地下储气库（一个采终的气田）及附近的气枪震源地震观测点，将大量天然气注入或采出气田，进行干预地下构造应力应变场的试验及观测。用气枪激发的高稳定重复的地震波扫描气田，观测储气量改变时气田声速变化、地表升降及地面重力异常，考虑气田的渗流场、应力应变场对声速场的影响，建立多物理场模型，用有限元方法数值模拟，评估人工干预地下构造的应力应变场的变化范围和变化强度。该课题的完成，近期将为邻近储气库的乌鲁木齐市的地震安全积累资料，远期将为人工干预地下构造积累数据和经验，为减少浅源灾难性地震的发生探索人工干预地下构造的工程原理及其可行性。