鱼骨刺柔性管在碳酸盐岩缝洞型油藏应用的数值模拟研究

Numerical Simulation of Fishbone Flexible Pipes in Fractured Vuggy Carbonate Reservoirs

塔河油田碳酸盐岩缝洞型油藏水平井酸压投产时,存在笼统酸压效果不理想,分段酸压难度大、工具选择困难、裂缝走向难控制等问题,为此,采用数值模拟方法分析了碳酸盐岩缝洞型油藏水平井采用鱼骨刺柔性管完井时的增产效果及经济性。结果表明:鱼骨刺柔性管未连通有效缝洞体时,单井产油量随着鱼骨刺柔性管装置数量增加而增加,但是平均单套装置的增油量呈现先增加后减小的趋势,连通缝洞体概率较低的井建议采用6~10套鱼骨刺柔性管装置进行完井作业;连通单个有效缝洞体时,产油量随缝洞体的体积增大而增加;连通多个缝洞体且缝洞体总体积相同时,累计产油量随着连通缝洞体的数量增加而增大;连通1个以上缝洞体即可取得较好的经济效益。研究结果表明,塔河油田碳酸盐岩缝洞型油藏水平井可以采用鱼骨刺柔性管完井。

The development of fractured vuggy carbonate reservoirs in Tahe Oilfield through horizontal wells with acid fracturing typically perform poorly after normal acid fracturing, and with difficulty after the application of staged acid fracturing, even with proper tools selection and fracture orientation control. Under such circumstances, numerical simulations were performed to determine the technical feasibility and economic performance of of horizontal wells with flexible fishbone pipes in completion in fractured vuggy carbonate reservoirs. Simulation results showed that production from individual well may increase with the quantity of flexible fishbone pipes when they failed to establish communication among effective fractures and vugs. In addition, production enhancement from each individual set of pipes would increase primarily followed by production decline. For wells with poor communication among fractures, 6-10 sets of flexible fishbone pipes can be placed during well completion For wells with communication among fractures or vugs, oil production would increase and the increase was determined by fractures or vug volume. In general, satisfactory economic performances might be reached as long as fractures or vugs establish communication with flexible fishbone pipes. Research results showed that flexible fishbone pipes completion techniques could be deployed for horizontal wells of fractured vuggy carbonate reservoirs in Tahe Oilfield. It may provide necessary guidance for pilot tests in the application of flexible fishbone pipes in completion operations.