变形介质低渗透油藏水平井产能特征

Productivity of horizontal well in deformation medium of low-permeability reservoirs

针对低渗透油藏水平井生产过程中井底附近渗流场的复杂性问题,对低渗透油藏水平井远井区域和近井区域渗流场的多种基本渗流形态进行了分析,基于稳定渗流理论,给出了考虑启动压力梯度的变形介质在低渗透油藏中3种流态并存的水平井产能计算公式。通过实例计算分析了水平井产能特征和不同水平井井段长度条件下各种流态的主次关系与转换特征。研究结果表明,低渗透油藏水平井的产能随启动压力梯度和介质变形系数的增大而降低;随水平井段长度的增加,远井区域先以径向流为主,逐步转化为平行流;近井区域以径向流为主。

Aiming at the complexity and multiple flow forms at the bottom of flow field in horizontal well, the basic flow forms of flu id field near and far horizontal wells in low-permeability reservoir were analyzed. The calculating formulas for producing capacity of horizontal well in low-permeability reservoir with deformation medium and start-up pressure gradient were developed. The productivity characteristics of horizontal well and various flow features in different horizontal section of well were discussed by analyzing and calculating examples. The results showed that the productivity of horizontal well in low-permeability reservoir decreased with the increment of start-up pressure gradient and deformation coefficient of medium. As the horizontal section of well got longer, the fluid far away from horizontal well changed from the radial flow to the planar flow. The main pattern of fluid near horizontal well was radial flow.