低渗透油藏启动压力梯度实验研究  

An experimental study on threshold pressure gradient in low pernteability reservoir

作　　者：汪全林[1] 唐海[1] 吕栋梁[1] 彭得兵[1] 郭粉转[1] 

机构地区：[1]西南石油大学石油工程学院,四川成都610500

出　　处：《油气地质与采收率》2011年第1期97-100,117-118,共4页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"大型油气田及煤层气开发"项目13课题5"低渗透油藏中高含水期综合调整技术"(2008ZX05013-005)

摘　　要：随着低渗透油藏的开发,启动压力梯度对开发有不可忽视的影响,它是流体边界层性质异常和流体塑性的综合表现形式。选取青海某油田低渗透油藏天然岩心,根据实验数据拟合结果,分别比较了各渗流方程的准确性。结果表明,幂函数和二次多项式的拟合结果最佳。根据所得启动压力梯度,分别讨论了启动压力梯度与渗透率、流体粘度、流度的关系。研究表明,低渗透油藏启动压力梯度与渗透率、流度成反比,与流体粘度成正比,并且与渗透率和流度之间有较好的乘幂关系。从高才尼—卡尔曼公式出发,得出了启动压力梯度与岩石孔隙度、孔道半径成反比,与流体粘度、孔道迂曲度、比面成正比。从推导的公式可知,岩石孔道半径和迂曲度对启动压力梯度的影响比孔隙度和流体粘度大。该研究成果对油田生产现场减小启动压力,降低渗流阻力有着一定的指导意义。With the exploration of low-permeability reservoirs,threshold pressure gradient can not be ignored in the process of ex-ploration.The abnormal property of boundary and the plastic flow of oil are thought to be the cause of the threshold pressure gradi-ent in the low permeability.Selecting the core of low permeability reservoir,and using experimental methods,the accuracy of flu-id equations is verified respectively.Research shows that the matching of power laws and quadratic polynomial are the best among all.The relationships between threshold pressure gradient,permeability,viscosity and fluidity are discussed thereafter respectively according to the value of threshold pressure gradient.The research shows that threshold pressure gradient is inversely proportional to permeability and fluidity,and proportional to viscosity,and has a good relationship with permeability and fluidity in power laws.The threshold pressure gradient is inverse proportional to porosity,passageways radius,and proportional to viscosity,tortuosity,and specific-surface based on the Kozeny-Carman formula.The theory is that,the tortuosity and passageways radius have more influence on threshold pressure gradient than porosity and viscosity according to the derived formula.This study has a definite significance for reducing the threshold pressure and the seepage resistance in the field.

关 键 词：低渗透油藏 渗流 启动压力梯度 流度 孔隙度 流体粘度 渗透率 

分 类 号：TE311[石油与天然气工程—油气田开发工程]