Study on influencing factors and mechanism of land subsidence in delta resource exploitation area of Shengli oilfield

To prevent or reduce the loss caused by land subsidence in delta region, the land subsidence of the Zhuangxi–Wuhaozhuang oil area in Shengli Oilfield is predicted based on the elastic theory of porous medium and classical consolidation theory, and the prediction results are analyzed and verified by numerical simulation. The influencing factors and mechanism of land subsidence in delta resource exploitation area are studied. The research shows that: (1) the land subsidence in delta resource exploitation area is mainly caused by the underground brine exploitation, oil exploitation, consolidation of loose sediments, shallow groundwater exploitation, and soil load consolidation. The maximum land subsidence rate obtained by numerical simulation is 22 mm/a for single oil well and 81 mm/a for single brine well. (2) Pore pressure, physical and mechanical parameters of oil and brine reservoirs, development mode, and development degree are influencing factors of land subsidence in delta resource exploitation area, and pore pressure, permeability, and reservoir burial depth are controlling factors. (3) The exploitation wells in the Zhuangxi–Wuhaozhuang oil area are dense, and the influence range of land subsidence of different exploitation wells overlaps, which further aggravates the uneven land subsidence, and makes the result of InSAR subsidence monitoring larger.