摘要
松辽盆地南部长岭断陷营城组火成岩为低压非均质气藏,为了满足勘探需要采用欠平衡钻井施工,由于岩性复杂常常导致钻井施工异常困难。在YS-2井实施低密度聚合醇防塌钻井液,该钻井液利用聚合醇溶液的浊点效应,同时配合非渗透屏蔽剂和封堵防塌剂,可防止钻井液滤液侵入地层,既加强了防塌、润滑的作用,又可达到油气层保护的效果。对于火成岩非均质气藏进行勘探,采用低密度聚合醇防塌钻井液实施欠平衡作业,钻井液性能相对于油基钻井液易于控制,有利于气液分离、缩短钻井液配制时间、及时处理探井施工中因地层因素导致的复杂情况,降低使用成本;通过密度的合理调控充分实现了欠平衡钻进的地质目的,且配合有效的防塌措施实现了井壁稳定与安全快速钻进。
Underbalanced drilling technology was adopted in the exploration activity in the south of Songliao Basin, where a lowpressure inhomogeneous gas reservoir is located in the igneous Yingcheng Formation(in Changling fault). Drilling operation was very difficult because of the complex formation characteristics. A low density polyalcohol inhibitive drilling fluid was used to drill the Well YS-2, featuring the use of cloud point effect of polyalcohol and the use of non-permeable additives and plugging agents which prevent invasion of mud filtrate into formations. Compared with oil base drilling fluid, this water base polyalcohol drilling fluid has properties that are easy to control and maintain, and gas and liquid are easy to be separated from each other. Other advantages include easy-formulation of mud, timely treatment of downhole troubles caused by drilled formations, and low drilling cost. Safe andfast drilling of the Well YS-2 was achieved with the underbalanced technology by carefully engineering mud density and inhibitive capacity of the drilling fluid.
出处
《钻井液与完井液》
CAS
北大核心
2014年第6期82-85,101-102,共4页
Drilling Fluid & Completion Fluid
关键词
聚合醇钻井液
低密钻井液
欠平衡钻井
井眼稳定
火成岩地层
Drilling fluid
Underbalanced drilling
Igneous rock
Low density
Poly alcohol
Borehole collapse prevention
Songnan area
