多分支水平井产能敏感性分析

Sensitivity analysis of multilateral horizontal well productivity

多分支水平井是开发低渗透油气藏的重要手段。结合目前先进的多分支水平井半解析产能预测模型,对影响多分支水平井产能的重要油藏因素和井型参数进行了敏感性分析。研究结果表明:油藏供给边界性质及主井筒的展布方位会对多分支水平井产能产生很大影响,其中四周定压油藏边界的影响最明显;在断块油藏中,应将多分支水平井布于油藏中部,根据多分支水平井的泄油面积来确定井网密度。分支长度、分支数目、分支角度是影响多分支水平井产能的重要井型参数,应选择尽可能大的分支长度,三分支以上的分支数目和不小于30°的分支角度。

Multilateral horizontal well is an important way to the development of low-permeability oil and gas reservoirs.Reservoir factors and well-type factors which influence the productivity of multilateral horizontal wells are analyzed using the advanced semianalytical model for multilateral horizontal well productivity prediction.It is concluded that the features of reservoir boundary and the spread of the main bore of multilateral wells are crucial to the productivity of multilateral horizontal wells especially in the reservoir whose boundary is constant flux.The multilateral horizontal wells should be positioned in the middle of the massive reservoir.The well pattern density should be selected according to the drainage area of multilateral horizontal wells.Branch length,branch number and branch angle are the key parameters which influence the productivity of multilateral horizontal wells.It is concluded that： a large branch length should be selected;the branch number should be more than three;the branch angle should be no more less than thirty degrees.