遇水膨胀封隔器分段酸压技术及应用

Technology and Application of Multi-stage Acid Fracturing by Water-swelling Packer

中国西北某油田奥陶系碳酸盐岩油藏以裂缝溶洞为主要储集空间,具有超深、高压和高温的特点,水平井笼统酸压存在效果差以及分段改造方式和工具选择困难等问题。阐述了遇水膨胀封隔器分段酸压技术原理、技术关键、施工程序和工具性能参数。根据试验井实际钻、录、测井资料和分段酸压级数优化结果,结合储层裂缝、溶蚀孔洞特点,并考虑完井工具对井径、井眼轨迹的要求,以有利储层段有效改造为原则,确定分段酸压完井方案,优化了封隔器下入和膨胀座封时间,开展了分段酸压优化设计以及现场试验。试验表明:分段酸压完井方案及酸压优化设计方法是正确的,但投球滑套等工具质量以及完井酸压过程中的质量控制需进一步提高和完善。

The ordovician carbonate reservoir of one oilfield in the northwest of China, is mainly fracture cavern, with the reservoir features of ultra-deep, high pressure and high temperature; the effect of horizontal conventional acid fracturing is very limited, and there are still difficulties in the selection of multi-stage stimulation methods and tools. This paper introduces the technical principle, key technical aspects, operation program and tool performance of multi-stage acid fracturing by water- swelling packers. Based on actual drilling/mud logging/logging data and the optimized stages of multi-stage acid fracturing, and in combination with the characteristics of reservoir fractures and solution caves, as well as the requirements of completion tools on borehole diameter and trajectory, We determine the completion program of multi-stage acid fracturing, optimize the RIH and inflation setting time of packers, and improve the multi-stage acid fracturing design and complete field test, under the principle of effective stimulation and favorable reservoirs. The field test results show that the completion program of multi-stage acid fracturing and optimized acid fracturing design are both correct, but the quality of tools like ball injection sliding sleeve and the quality control in acid fracturing completion still need to be improved.