连续油管拖动底封水力喷射环空加砂分段压裂技术

Technology of Coiled Tubing Abrasive Perforating and Annulus Fracturing

连续油管拖动底封水力喷射环空加砂压裂工艺是集射孔、压裂、封隔于一体的新型增产改造技术。针对常规结构Y211型封隔器或K344型封隔器及喷枪不完全满足工艺需求的问题,采用Solidworks、Ansys等软件对新型Y211型封隔器、喷枪等工具进行优化设计。创新设计特殊密封结构胶筒及其肩部保护机构,研制抗拉强度和延伸率高的胶料配方,降低了坐封力,提高了承压性能。优化卡瓦结构,设计防砂卡机构,提高了封隔器锚定及坐封可靠性。研制了内嵌整体式喷枪,提高耐磨性能,满足多段压裂需要。通过攻关研究,工艺管柱达到耐温120℃、承压70 MPa指标,单趟管柱可压裂14段,成本比国外降低50%以上。

The technology of abrasive perforating and annulus fracturing with coiled tubing is a no- vel stimulation method that integrates perforation with fracturing and zonal isolation. The bottom packer is set to seal the annulus between casing and tubing to plug lower reservoirs. Conventional structure Y211 packer or K344 packer and spray gun does not fully meet the technical requirements. So the design of the inflatable packers and hydraulic jet was optimized and improved by the software of Ansys and Solidworks. Both the innovative design of packing element and its shoulder protection mechanism and the formula of elastomer with high tensile strength and elongation could reduce the setting pressure and improve the bearing performance. Optimized slip structure and sand stuck prevention mechanism could improve the packers＇ anchor and sealing reliability. The integral embedded hydraulic jet improves the wear resistance of the string to fracture the multiple stages with high efficiency. The pipe string rated up to 70 MPa at 120 degrees Celsius with maximum 14 stages in one trip. The cost was reduced more than 50% compared with that of foreign countries.