摘要
塔中油田白垩系、三叠系、二叠系和石炭系地层在压实过程中形成巨厚硬脆性泥岩层段,层理裂缝发育,为避免在起钻和短提时发生垮塌、卡钻事故,针对易垮塌层制定了专项封堵防塌施工方案。并优选出了如下的专项封堵防塌钻井液配方：井浆＋（2%~3%）SY-A01＋（1%~2%）TYRF-1＋（1%~2%）PGCS-1＋（3%~5%）KCl＋（0.5%~1%）TP-2＋（3%~5%）超细碳酸钙＋（2%~3%）油溶性润滑剂＋加重剂,利用不同种类、不同粒径防塌剂的＂多元协同＂作用,在井壁上形成一层具有防渗透和防冲刷能力的封堵层。中古431-H4井针对易垮塌层段进行4次专项封堵,在长达55.3 d浸泡况下,5次起下钻和3次短程起下钻过程中井壁稳定。该技术能够解决硬脆性泥岩和玄武岩引起的井壁失稳问题,能有效降低钻井液防塌成本,不影响纯钻时效。
The Cretaceous,Triassic,Permian and Carboniferous systems are thick hard and brittle shales full of fractures in Tazhong area.Bore hole cave-in and collapse were frequently encountered in these formations during drilling.In drilling the Well Zhonggu431-H4,a special plugging and collapse prevention technology had to be used to avoid down hole troubles.Several special plugging agents with ＂synergistic effect＂,and a special plugging technology were adopted seal the borehole wall,preventing it against erosion and water penetration.No downhole problems were encountered after 55.3 days of exposure of borehole wall to drilling fluid,5 times of whole tripping and 3 times short tripping.The special plugging and collapse prevention technology successfully solved the downhole problems caused by the characteristics of formation penetrated,effectively reduced drilling cost and NPT.
出处
《钻井液与完井液》
CAS
北大核心
2015年第2期58-60,101,共3页
Drilling Fluid & Completion Fluid
关键词
硬脆性泥岩
封堵防塌
多元协同
井壁稳定
Hard and brittle shale
Plugging and collapse prevention
Synergy
Borehole stabilization
