基于流线模拟的压裂水平井渗流场及产能特征

FLOW CHARACTERISTICS AND PRODUCTIVITY OF FRACTURED HORIZONTAL WELLS BASED ON STREAMLINE SIMULATION

注水和压裂使低渗油藏的流体渗流规律更加复杂,为了直观反映压裂水平井渗流场和产能特征,利用流线模拟方法,研究了压裂水平井流线分布特征、裂缝产能分布规律、裂缝长度对开发效果的影响。基于此,设计了纺锤形压裂水平井布井。研究表明:压裂水平井端缝与注水井间区域的流线分布密集,水平段中部区域流线稀疏;边部裂缝汇集着绝大多数流线,中间裂缝的流线数量较少;边部裂缝的产油/产液能力高于中间裂缝,但边部裂缝见水时间早,含水率上升快;与等缝长压裂水平井相比,纺锤形压裂水平井可以增大水平段中部区域的流线密度,提高水驱波及效率,10年采出程度提高0.77%,含水率降低18.05%,最终采收率提高1.6%(综合含水率95%)。

Injection and fracturing make the seepage in low permeability reservoir more complex.In order to visually reflect the flow characteristics of fractured horizontal wells,the streamline simulation method is used to investigate the regulations of fractured horizontal wells,such as:streamline distribution,productivity of different fractures and effect of fracture length on the development.Fractured horizontal well with spindle-type is designed.Streamline simulation has shown that:streamline distribution in the region between injection well and fracture at the end of horizontal well is more intensive than that of other regions;among the three fractures,the one at the end of horizontal well receives the vast majority of streamlines,only few flow into the middle fracture.Productivity(including oil and liquid) in fractures at the end of horizontal well is higher than that of the middle fracture.Early water breakthrough and sharp water rising lead to rapid increase of water cut for fractured horizontal wells.Compared with general fractured horizontal wells,the streamline in spindle-type is more uniform,which can enhance oil recovery by 0.77% for the first 10 years and reduce water cut by 18.05%,and the final recovery will be enhanced by 1.6%.