胜利低渗油田水平井筛管分段控流完井技术

为了延缓水平井筛管完井后期的含水上升速率、延长水平井生产寿命,胜利油田提出并推广应用了水平井筛管分段控流完井技术。水平井筛管分段控流完井的技术原理为:首先,要根据油井的油藏地质特征,利用管外封隔器将水平油层段合理分段,实现各个不同层系间的有效隔离;然后,利用数值模拟方法计算出油井合理的日产液量,根据油藏的物性参数制订产能分配方案、计算各段需要的渗流面积;最后根据计算结果在各段下入不同孔密或缝密的控流筛管,调节各段生产压差,使产层均衡供液,并控制底水均匀地向水平井筒推进。介绍了分段管外封隔器、变密度控流筛管、变密度割缝管等分段控流完井工具,及分段控流完井工艺。从推广应用至今,该完井技术已经在胜利油田及其所属外地区块的30余口水平井中进行了应用。应用结果表明,该技术稳油控水效果明显,油井含水率可比邻井同期下降10%,能实现各不同层系间的有效隔离、延长油井无水或低含水开采期。 

Well Completion Technique with Screen Pipe Controlling Flow by Segments in Horizontal Well of Low Permeability Resevoirs in Shengli Oilfield

In order to slow down the rise of water cut after completion with screen pipe and prolong production life of horizontal wells,a completion method for horizontal wells with screen pipe controlling flow by segments has been proposed and applied in Shengli Oilfield.Its technical characteristics are analyzed as that,according to geological characteristics of the reservoir,different formations in oil layer are first isolated with external casing packers by segments;secondly,numerical simulation is used to calculate the reasonable daily fluid production rate of the well,then according to reservoir properties,the productivity distribution scheme is made to determine reasonable drainage area of each section;thirdly,flow-control screen pipe with different slot size and spacing is set in terms of the calculation results.The flow-control screen pipe can regulate production pressure drop of each section to achieve even liquid production in oil layer,and control bottom water flowing to horizontal wellbore evenly.The section flow-control tools such as external casing packer,flow-control screen pipe of variable slot size and spacing are introduced,as well as the well completion of flow control by segment.Field application effect of the completion method is analyzed.Up to now,the technique has been applied to more than 30 wells in Shengli Oilfield.Actual application indicates that it works well in controlling water cut and stablizing oil production.The water cut of these wells dropped 10% at the same period than those nearby wells which haven’t applied the technique.The technique can isolate different formations effectively and prolong water free or low water cut production period.