呼图壁地下储气库重力变化及其影响因素初步分析

PRELIMINARY ANALYSIS ON CHARACTERISTICS OF GRAVITY CHANGE AND ITS INFLUENCING FACTORS IN HUTUBI UNDERGROUND GAS STORAGE RESERVOIR

利用呼图壁地下储气库2013～2016年共7期流动重力、水准观测资料,对储气库地表重力场变化特征及其影响因素进行了初步分析。研究结果表明,影响地下储气库重力场的主要因素有地下介质密度变化、注采气压力变化、地下水位和土壤湿度变化和地表升降变化等。其中,重力场变化中占主导作用的影响因素为地表升降变化和地下水位的变化,储气库区内的测点重力变化主要来自于地表升降(储气库注采气压力变化导致的地表升降)和地下介质密度变化,储气库外部的测点重力变化主要来自于地表升降(季节性地表升降和地下水超采引起的地表沉降)和地下水位的变化。

Preliminary analyzed characteristics of gravity change and its influencing factors in the Hutubi underground gas storage reservoir using the movile gravity, leveling servey data of 7 years from 2013 to 2016. Results showed that the main factors influencing underground gas storage gravity filed included underground materials density change, injection and withdrawal gas pressure change, underground water level and soil moisture change, and ground surface fluctuation. In these factors, ground surface fluctuation and underground water level changes were the main influencing factor of gravity change. The gravity change in the gas reservoir area mainly caused by ground fluctuation （ground fluctuation caused by gas injection and withdrawal changes） and density change of underground materials, gravity change outside the gas reservoir area mainly caused by ground fluctuation （ seasonal ground fluctuation and ground subsiding caused by groundwater over exploitation） and underground water level changes.