低渗透未饱和油藏产能计算及其影响因素研究

研究了低渗透未饱和油藏的产能公式，通过达西公式，推导并得到了考虑启动压力梯度和介质变形的未饱和油藏的IPR曲线方程。结合矿场数据对IPR曲线方程进行了验证，并研究了启动压力梯度、介质变形、含水率对产量的影响。研究结果表明：在相同条件下，启动压力梯度越大、变形系数越大，产油量越低；井底流压小于饱和压力时，IPR曲线存在最大产量点(拐点)；相同条件下启动压力梯度越小、变形系数越大，最大产量点对应的井底流压越高。含水率变化对最大产量点位置影响不大。研究成果对合理开发低渗透未饱和油藏具有理论指导意义。

PRODUCTIVITY CALCULATION AND IMPACTING FACTORS OF LOW PERMEABILITY UNSATURATED RESERVOIR

Low permeability unsaturated oil reservoir is studied in this paper.By using Darcy formula，the IPR equation of unsaturated reservoir considering threshold pressure gradient and media deformation is derived.The IPR curve is tested with field data，and threshold pressure gradient，media deformation and water cut are studied respectively to explain how the production is affected.The results show that，the oil production of unsaturated reservoir decreases with increasing threshold pressure gradient and media deformation under the same conditions.The IPR curve contains the maximum oil production when the bottom hole flowing pressure is below the bubble point pressure.Under the same conditions，the maximum production pressure increases with decreasing threshold pressure gradient and deformation factor.Water cut has little effect on oil production.The research can theoretically guide the reasonable development of unsaturated reservoir.