基于PS-InSAR监测的石油开采地表下沉模型反演

石油开采造成油层压实,引起地表下沉,导致地表移动变形,对地面设施产生损害影响。石油开采引起的地表下沉比较缓慢,应用常规的大地测量监测技术无法实现大区域动态监测。为了准确掌握某油田的地表下沉的发展过程,本文采用33景升轨Sentinel-1A数据,运用PS-InSAR技术对油田进行地表下沉监测,获取了该区域2017年3月至2019年11月的地面下沉场,分析了该区域在监测时间段内的下沉演化情况,该油田下沉面积达29.5km2,监测时间段内该采油厂最大下沉速率为-210.9mm/a,最大累积下沉量达-585.6mm;根据地表下沉理论,应用参数反分析的方法,建立了基于弹性薄板理论的地表下沉与变形计算模型。根据反演模型计算,截至2019年11月,该油田地表最大倾斜为0.47mm/m,最大水平拉伸为0.42mm/m,最大压缩变形分别为-0.34mm/m,计算结果为评价该区域开采损害风险评估提供了依据。

Surface Subsidence Inversion Model with PS-InSAR Monitoring in Petroleum Exploitation

Petroleum production will lead the reservoir compression, and then causes surface subsidence. The surface subsidence caused by oil exploitation is slow and the dynamic monitoring of large area cannot be realized by the conventional geodetic monitoring technology.Therefore, according to the oil-field surface subsidence process, the 33 ascending Sentinel-1A SAR data and PS-InSAR technique are selected to monitor the oilfield surface subsidence in this paper. It obtains the surface subsidence in the area from March 2017 to November 2019, and that analyses the subsidence evolution process within the monitoring period. The results illustrate that the oil-field subsidence area is 29.5 km2, the maximum subsidence speed is 210.9 mm/a, and the maximum subsidence is 585.6 mm. Finally, according to the theory of surface subsidence, the calculation model of surface subsidence and deformation in this area is established by using the method of parameter inverse analysis. According to the inversion model, the maximum surface tilt is 0.47mm /m, the maximum horizontal stretching is + 0.42mm /m, and the maximum compression deformation is -0.34mm /m respectively,which will provide a basis for mining damage assessment.