基于数值模拟的海上低渗油藏压驱选井选层标准OA

To address the lack of clear criteria for well and layer selection in the offshore applications of fracturing-flooding technology,this study develops a refined numerical simulation method to quantitatively characterize the oil enhancement mechanisms associated with high-pressure fracture-induced permeability improvement,surfactant-assisted oil displacement,and soak-imbibition processes.Based on numerical simulations,selection criteria for wells and layers suitable for fracturing-flooding are systematically investigated,and the relative influence of key selection indicators on incremental oil production is analyzed.Results show that the oil-saturation condition play a more critical role than original reserves and physical properties of the reservoir in well and layer selection.Specifically,a pressure maintenance level greater than 0.4 and an oil saturation of exceeding 40%are identified as the lower limits for candidate wells and layers.After fracturing-flooding treatment of the optimized target wells and layers,the initial incremental oil production reaches 50 m3/d,and the productivity index of the target layer increases from 1.2 m3/(d·MPa)to 9.2 m3/(d·MPa),and the cumulative incremental oil production reaches 1.01×104 m3 within six months,indicating that the fracturing-flooding performance meets the design requirements.Field practice shows that the proposed refined numerical simulation approach—which incorporates formation energy replenishment,pore and permeability enhancement,pressure-induced fracturing,surfactant-assisted washing oil,and imbibition displacement mechanisms—together with the established well and layer selection criteria,provides effective technical support for fracturing-flooding operations in offshore low-permeability reservoirs.