考虑渗透率和流体黏度的致密油藏探测半径

探测半径是评价油藏控制程度和井控储量的重要参数。为了解决低渗透致密油藏探测半径计算方面存在的问题,建立了考虑渗透率和黏度的模型,推出了新的导压系数,得到了考虑流体和地层因素的微分方程。在此基础上,应用稳态依次替换法和质量守恒法推导出相应的探测半径方程,并用数值方法求解。研究结果表明:低渗透致密油藏地层中新的导压系数比经典理论中的导压系数小;探测半径与井的产量有关,同时也与渗透率和黏度的变形系数有关,渗透率的变形效应会减小探测半径,黏度的变形效应会增大探测半径。

Investigation radius of tight oil reservoir considering change of permeability and fluid viscosity

Investigation radius is an important parameter to evaluate reservoir control degree and well controlled reserves.In order to solve the investigation radius calculation of low permeability tight reservoir,the permeability and viscosity pressure coefficient model was built and a new transmissibility coefficient and differential equation considering fluid and formation factor were deduced.On the basis of the above analysis,the corresponding investigation radius was derived by the method of steady state replacement and material balance,and the solution was solved by numerical method.The results show that in the low permeability and tight reservoir,the new transmissibility coefficient is smaller than that of the classical theory.The investigation radius is related to the flow rate of the well,and it is also related to the deformation coefficient of permeability and viscosity.The deformation effect of permeability will decrease the detection radius,while deformation effect of viscosity will increase the detection radius,which provides a reference for the development of low permeability tight reservoir.