海上低渗透油藏试验井组整体压裂可行性研究

Feasibility Study on Integrated Fracturing for A Testing Well Group in Offshore Low-permeability Reservoirs

针对低渗透油藏压裂井生产模拟的不完善性．建立了考虑人工裂缝失效性的低渗透油藏非达西渗流数值模型。对渤海湾某油田“一注两采”试验井组进行了整体压裂优化设计，最优结果如下：注采井距由240～270m，油井裂缝半长为120m，导流能力为30μm^2·cm.研究表明，对该区块买施整体压裂在技术和经济上罡可行的。按在平台上施工考虑，将规模控制在用液量250m^3，平均砂比20％-25％，前置液比例35％～40％，排量3m^3／min，加砂量27m^3，模拟的裂缝参数与优化结果相符。通过对井组在不压裂和压裂油井餐件下生产20年的产量与油价的敏感性分析知，实施水力压裂措施后的油价下限可由无措施时的100美元／桶左右降到60美元／桶。

In allusion to the imperfection of production simulation of low permeability reservoirs,a mathematical model considering the low permeability non-Darcy flow and fracture flow conductivity failure in artificial fracturing was established.An integrated fracturing in a well group of one producing well and two injection wells was designed in an oilfield of Bohai Area.The optimized injector-producer spacing was ranged from 240 to 270m,the fracture half length was 120m,and the flow conductivity was 30μm2·cm.Research result shows that integral fracturing technology is feasible both in technology and economy.Based on hydraulic fracturing on the platform,the operation fluid volume is controlled approximately to 250m3,average sand to liquid ratio and pad fluid ratio are between 20%~25% and 35%~40% respectively.When the operation discharge is 3m3/min and the total sand usage volume is 27m3,the simulation fracturing parameters are in good agreement with the optimization results.From the analysis of different oil prices with NPV and IRR under the conditions of the well group producing for 20 years with hydraulic fracturing treatments,minimum economic oil price could be lowered from about $100/bbl to $60/bbl by fracturing