砾石充填完井多层油藏井底压力评价

MULTI-LAYER RESERVOIR GRAVEL-PACKED WELL-COMPLETION PRESSURE EVALUATION

正确地评价砾石充填完井多层油藏井底压力 ,对于加深认识油层内的渗流机理 ,保护油层 ,最大程度地发挥油井产能等具有指导意义。笔者针对目前不合理的压力评价方法 ,提出了全新的算法。根据多层砾石充填完井的渗流特点 ,将每个产层在径向上分成 3个区域 ,即砾石充填区、射孔区、地层径向流区 ,每个区域有各自的渗流方程 ,对n层油藏有 3n个渗流方程 ,将每个区域的方程用Green函数来表示 ,由各层的Green函数得到井筒混合压力、分层压力及分层产量在Laplace空间上的解 ,最后得到每层各区域的压力损失、表皮系数以及井底压力和分层产量与时间的变化关系。文章最后以两层油藏为例 ,运用该算法得出了合理的结论。

The accurate evluation of gravel packed well completion pressure of multi layer reservoir is significant for us to deepen the understanding of microscopic mechanism of formations protection and develop production of oil wells furthest.On account of the unreasonableness of the current methods a novel method is brought forth.As to multi layer reservoirs,each layer can be divided into three areas:area of gravel packing,area of perforation and area of radial flow.Each area has its own governing equaiton and the solution is expressed by Green function.The well bore pressure and layer rate is given through Green function in Laplace space.The pressure drop and skin factor is obtained also in each area.In the end,a case of two layer reservoir is studied and the reasonable conclusions are acquired by applying our novel method.