三维各向异性油藏水平井产能新公式  

A new formula for predicting productivity of horizontal wells in three-dimensional anisotropic reservoirs

作　　者：贾晓飞[1,2] 雷光伦 孙召勃[2] 姚传进 JIA Xiaofei;LEI Guanglun;SUN Zhaobo;YAO Chuanjin(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China;Bohai Oilfield Research institute,Tianjin Branch Company,CNOOC Ltd.,Tianjin City,300459,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]中海石油(中国)有限公司天津分公司渤海石油研究院,天津300459

出　　处：《油气地质与采收率》2019年第2期113-119,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"渤海油田高效开发示范工程"(2016ZX05058);中海石油(中国)有限公司综合科研项目"渤海双高油田挖潜关键技术研究"(YXKY-2018-TJ-04)

摘　　要：目前常用的水平井产能预测公式未考虑实际油藏的三维各向异性特点及水平井渗流中典型的平面线性流特征,因此,产能预测结果往往过于乐观。针对此问题,通过坐标变换将三维各向异性油藏转换为等效的各向同性油藏,在此基础上,从水平井典型渗流特征出发,将油藏内流动区域划分为外部平面径向流、中间平面线性流以及内部垂向径向流3个区域,利用水电相似原理和等值渗流阻力方法,推导出三维各向异性油藏综合形式水平井产能新公式。与常规水平井产能公式对比发现:随着水平井长度的增加,平面线性流的渗流阻力及对产能的影响逐渐增大;平面各向异性对水平井产能影响显著,其变化规律受水平井与油藏主渗透率方向夹角的控制;水平井产能随着油藏垂直渗透率与平面渗透率比值的增大而增加,随着水平井与油藏主渗透率方向夹角的增加而增加。实例应用表明新公式预测精度大幅提高,误差仅为3%,可以用于指导水平井产能预测、水平井长度和方位优化。The three-dimensional anisotropy of actual reservoirs and the typical linear flow characteristics in horizontal well seepage are not considered in commonly used horizontal well productivity prediction formula,and thus the productivity prediction results tend to be optimistic.Aiming at solving this problem,the three-dimensional anisotropic reservoir is converted into an equivalent isotropic reservoir through coordinate transformation.Then the flow region in the reservoir can be divided into external region with plane radial flow,middle region with plane linear flow and internal region with vertical radial flow based on typical seepage characteristics of the horizontal wells.A new comprehensive formula for calculating the productivity of horizontal wells in a three-dimensional anisotropic reservoir was derived by using the hydropower similarity principle and the equivalent flow resistance method.Comparison with the conventional horizontal well productivity formula shows that the flow resistance of the plane linear flow and its influence on the productivity gradually increase with the increase of the length of the horizontal well;the plane anisotropy has significant influence on the productivity of the horizontal well,and its changing law is controlled by the angle between horizontal well and the main permeability direction of the reservoir;the productivity of the horizontal well increases with the increase of the vertical and horizontal permeability ratio,and increases with the increase of the angle between the horizontal well and the main permeability direction of the reservoir.The application shows that the new formula has higher prediction accuracy with an average deviation less than 3%,and it can be used to guide horizontal well productivity prediction and optimization of horizontal section length and azimuth.

关 键 词：水平井 产能预测 三维各向异性 线性流 新公式 

分 类 号：TE328[石油与天然气工程—油气田开发工程]