单泵同心双管分层注聚工艺的理论分析及应用

为了解决当前在疏松砂岩油藏分层注聚工艺中存在的易堵塞、易剪切、难测试等问题,提出了单泵同心双管分层注聚工艺;并组建了其系统动力学模型,其中包括通过室内实验回归得出的聚合物溶液流变性模型、不同剪切速率下的黏度损耗模型,以及通过理论推导得出的流型判别模型、流体流速及剪切速率模型、压力损耗模型及沿井筒的温度分布模型;在此基础上对该系统工作过程中各模型间的耦合关系进行研究,建立了系统模型的数值解法,进而编制应用程序.现场实例应用表明,该工艺技术可有效解决当前疏松砂岩分层注聚工艺所遇问题,且程序计算结果精度较高.

Theoretical study and application of the concentric double-pipe layered polymer injection with single pump

In order to solve the problems of easy plugging,easy shearing and difficult measuring in the layered polymer injection of unconsolidated sandstone reservoirs,the concentric double-pipe layered polymer injection technology with single pump is put forward,in which the pressure is controlled mainly by the friction resistance of pipe string and the pressure control of wellhead throttle valve is auxiliary.The dynamic models of the polymer injection system are established,including the rheology model of polymer solution and the viscosity loss model at different shear rates obtained by laboratory experiments,and the flow pattern distinction model,the velocity distribution model,the shear rate model,the pressure loss model and the wellbore temperature distribution model obtained by theoretical derivation.According to the coupling relationship among the models,the numerical solving method of them is presented,and the corresponding calculation program is also given.The pipe-string pressure ability of an example calculated by the models is 1.187 MPa,the control pressure of the pipe-string obtained by practical measurement is 1.200 MPa,and the error between both is very little.The result shows that the models can provide guidance for the design of the concentric double-pipe layered polymer injection technology with single pump.