基于精密水准和重力资料研究地下储气库形变特征

Study on the deformation characteristics of underground gas storage by using precise leveling and gravity data

利用9期水准观测资料和重力观测资料,对呼图壁储气库在不同注采气周期及各周期不同阶段地表沉降与局部重力场变化进行了系统精细研究。研究结果表明,现有优化观测网可有效监测储气库注采全过程地表形变与重力场变化。储气库注采可引起地表显著形变,注气引起的形变量大于采气引起的形变量,地表形变与注采周期对应较好;重力变化与注采周期相关性不强。不同注采量导致地表形变在相同月份也存在变化,形变量自NE向SW逐渐增大,且集中在井位附近。表明地表形变不仅与注采周期有关,也与注采量密切相关。

This paper systematically studied the surface subsidence and local gravity field change of Hutubi gas storage at different stages of different gas injection-production cycles by using 9 periods of leveling and gravity observation data.The result shows that the existing optimized observation network can effectively monitor the surface deformation and gravity field variation characteristics of gas storage during injection and production.The injection-production of gas storage can cause obvious surface deformation,and the ground deformation caused by gas injection is larger than that caused by gas production.The surface deformation corresponds well with the injectionproduction cycle,and the correlation between gravity change and the injection-production period is not obvious.Different injection-production volumes of gas storage lead to surface deformation in the same month and the deformation gradually increases from northeast to southwest,mainly near the gas wells.It indicates that surface deformation is not only related to the injection-production cycle but also closely related to injection-production volume.