裸眼分段压裂投球式滑套球座关键技术研究

Key Technology on Ball-Activated Sleeve for Open Hole Staged Fracturing

投球式滑套为裸眼分段压裂管柱中建立压裂级数和压裂过流通道的关键部件,但目前国内尚未开展滑套球座与其匹配的憋压球的密封能力、滑套球座的可钻性与耐冲蚀性方面的研究。通过滑套球座的结构设计、憋压球的材料优选及球座与憋压球密封能力的有限元分析与试验,研究了滑套球座与憋压球之间的密封技术;通过滑套球座材料优选和相关试验,研究了滑套球座的可钻性;通过滑套球座表面硬化处理探讨及冲蚀和密封试验,研究了其耐冲蚀性能。8井次共72段的现场试验表明,滑套设计合理,性能可靠,解决了投球式滑套高承压密封及完井管柱的全通径问题。

Ball-activated sleeve plays an important role in open hole staged fracturing ,w hich may deter-mine number of fracturing stages and flow channels .However ,studies have not been initiated in China on sealability between ball and ball seat ,drillability and erosion resistance of ball seat .In this paper ,finite ele-ment analysis and experiment were conducted in respect to structural design of ball seat ,selection of ball materials ,and sealability betw een ball and ball seat ,so as to find appropriate sealing techniques .Optimiza-tion of ball materials and relevant tests were made to identify the drillability of ball seat .Additionally ,sur-face hardening of ball seat was discussed ,together with corrosion and sealing experiments ,to analyze the corrosion resistance of the ball seat .This ball-activated sleeve technique was applied in 8 wells in 72 fractu-ring stages ,proving that it was reasonable and reliable ,and could be effectively used for sealing under high pressure and entire drifting of completion string .