严重漏失无返型井漏的分析与治理

ANALYSIS AND TREATMENT OF SERIOUS ABSORPTION WELL

川东高陡构造碳酸盐岩特大裂缝～溶洞性漏失井的防漏治漏 ,是目前尚未完全解决的研究课题。通过世界级特大漏失复杂井———大天 8井雷口坡、嘉陵江和飞仙关地层的漏失机理分析与井漏治理及多年的现场堵漏施工实践 ,总结出一套对付特大型裂缝～溶洞性严重漏失无返井的堵漏方法。利用地层压力与井眼液柱压力平衡原理 ,提出堵漏施工设计中应重点考虑的问题及钻具下入深度、顶替钻井液量、水泥浆的初凝时间等重要参数的求取方法。对特大型漏失无返井的堵漏是一种新的探索。但在井眼不规则和在施工动态条件下 ,堵漏液在井内运行产生的摩阻压力损耗的精确计算 ,还有待于进一步研究。

Antileakage and loss circulation control of extra feature/vugular absorption well in carbonate rock of high and steep structures in eastern Sichuan are an important research project. Through mechanism analysis of leak and field loss circulation control practice in Well Datian-8 that is a world's extra leak/complex well, a loss circulation control method used for dealing with extra feature/vugular absorption well is summarized. On the basis of equilibrium principle of formation pressure and wellbore fluid column pressure, the priority considered problems in loss circulation control operation design and acquisition of parameter about drill tool landing depth, displacing drilling fluid flow and presetting period of cement slurry etc. are proposed.