呼图壁地下储气库地表盖层变形的GPS研究

Study on the cap rock deformation of Hutubi underground gas storage by GPS

利用新疆呼图壁地下储气库地表盖层由13个点位组成的形变监测网的前5期GPS观测资料,研究地下储气库注、采过程中地表盖层的变形响应。通过获取地下储气库运行过程中地表盖层形变的三维时间序列,并结合井口压力数据,区分地下储气库在不同过程中的变形信号。研究结果表明,地表盖层在储气库注、采过程中水平方向上存在明显的"呼吸效应",储气库每MPa气井压力变化在注、采周期内对地表变形造成的影响在水平方向上分别达到1.02、1.24mm,垂直方向分别达到-1.11、0.86mm。

The deformation responses of cap rock of Underground Gas Storage （UGS）in Hutubi,Xinjiang were investigated during gas injection and production with the GPS data recorded by the deformation monitoring network which includs 13 observation sites.The time-series of threedimensional deformation of the cap rock were obtained in the UGS operation process,and the deformation signals in different phases were identified by combining the GPS data with wellhead pressure data.The results show that the respiratory response of cap rock is obvious during gas injection and production of UGS,and surface deformation due to 1MPa change of wellhead pressure is horizontally 1.02mm in gas injection and 1.24mm in gas production,and vertically-1.1 1 mm in gas injection and 0.86mm in gas production.