断块油田断层附近水平井产能

PRODUCTIVITY OF THE HORIZONTAL WELL NEAR THE FAULTS OF THE FAULT BLOCK OILFIELD

针对断块油田断层附近水平井产能预测难度较大的问题,采用离散化处理方法建立了断层附近油藏渗流和水平井井筒管流耦合模型,通过实例计算证明了模型的准确性。改变断层与井筒相对位置发现,井筒与断层平行时径向入流剖面呈"U"型分布;井筒距离断层越近产能越低,且产能降低幅度逐渐增大,当井筒紧贴断层时,产能降低为无断层时的一半。井筒与断层垂直时,远离断层端径向流量高于靠近断层端,且距离断层越近,跟趾端差异越明显、产能越低、产能降低幅度越大。断层附近水平井跟端靶点固定时,建议井眼轨迹垂直且远离断层,该情况下单井产能最高。整体上,井筒到断层距离对产能影响较大,井筒与断层夹角对径向入流剖面影响较大,这对断层附近水平井井眼轨迹设计具有一定指导意义。

In the light of the problem rather difficult to predict the horizontal well's productivity nearby the fault-block oilfield,with the help of discretization processing method,the coupling model was established simultaneously considering the reservoir seepage flow and wellbore pipe flow near the faults,and furthermore the accuracy of the model was confirmed by the living example. Several conclusions were found by changing the relative position between the faults and wellbore: in case the wellbore parallel with the faults,the radial inflow profile presents type-U distribution; the closer the distance between the above two is,the lower the productivity will be,so will be the greater the declined degree,when the borehole closely approaching the faults,the productivity is half that of no fault.. In case the wellbore perpendicular to the faults,the radial inflow far from the faults is larger than that of the other side,and the closer the distance between the wellbore and the faults,the more obvious the difference between the toe and heel is,the lower and the more decreased the productivity will be. In case the target point of the heel beside the faults is fixed,the well trajectory should departure from the faults considering the maximum productivity for the individual well. In a whole,the productivity is greatly influenced by the distance between the wellbore and faults,the radial inflow profile is seriously influenced by the included angle between the wellbore and faults. Allthe achievements possess a certain guiding significance for the design of the well trajectory nearby the faults.