摘要
聚合物驱是提高采收率的重要手段之一。根据聚合物驱油的物理过程,建立牛顿流体—非牛顿幂律流体—牛顿流体构成的三区复合油藏试井解释模型;通过拉普拉斯变换求得模型在拉普拉斯空间的解析解;利用Stehfest数值反演算法将拉普拉斯空间解析解反演到实空间,绘制出描述聚驱过程渗流特征的试井分析双对数理论曲线。根据导数曲线特征可识别出四个典型的流动阶段:纯井筒储集效应阶段、内区牛顿流体径向流阶段、聚合物区幂律流体径向流阶段、外区牛顿流体径向流阶段。在内区牛顿流体径向流阶段,压力导数双对数曲线呈值为0.5的水平线,其半径越大,持续时间越长;在聚合物区幂律流体径向流阶段,压力导数双对数曲线呈(1-n)(/3-n)斜率的直线,幂律指数越小,导数曲线斜率越大;在外区牛顿流体径向流阶段,压力导数双对数曲线呈值为0.5M13的水平直线。利用该模型可分析聚合物驱油的效果,指导聚合物驱油藏试井资料的有效解释。
Polymer flooding is one of the important means in enhancing oil recovery.Based on the physical process of polymer flooding,the well test model of three parts composite reservoir composed of Newtonian fluid/non-Newtonian power-law fluid/Newtonian fluid was established.The Laplace transform was used to obtain the analytical solution.The analytical solution of Laplace space was inverted to the real space by using Stehfest numerical inversion algorithm,and the double logarithmic theoretical curves of well test analysis describing the seepage characteristics of polymer flooding process were obtained.According to the characteristic of the derivative curve,four typical flow stages can be identified:the pure well bore effect stage,radial flow stage of inner part,polymer part and outer part.In the radial flow stage of inner part,the double logarithmic curves of the pressure derivative is a horizontal line with the value of 0.5.The larger the radius is,the longer the horizontal line will be.In radial flow stage of polymer part,the double logarithmic curves of the pressure derivative is a line with the slope of(1-n)(/3-n).The smaller the power law index is,the greater the slope of the derivative curve will be.In the radial flow stage of outer part,the double logarithmic curves of the pressure derivative is a horizontal line with the value of 0.5M13.The model can be used to analyse the effect of polymer flooding and guide the effective interpretation of well test data in polymer flooding reservoirs.
作者
刘文涛
张德富
程宏杰
王晓光
LIUWentao;ZHANG Defu;CHENG Hongjie;WANG Xiaoguang(Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)
出处
《油气藏评价与开发》
CSCD
2019年第4期26-30,共5页
Petroleum Reservoir Evaluation and Development
