新型甲酸盐/正电聚醇钻井液在南部滩海地区的应用

南部滩海是大港油田的重点勘探区域之一.该地区明化镇组和馆陶组地层粘土矿物以伊蒙无序间层为主,而且间层比很高,在钻井过程中常出现易塌、易漏失、起下钻遇阻及钻井液性能不稳定等复杂情况.为实现安全、快速钻进,充分利用甲酸盐与正电聚醇的协同增效作用,研制并优选出了一种甲酸盐/正电聚醇强抑制性钻井液.在张海5井等5口井的现场应用试验表明,这种钻井液体系表现出抗温性好、抑制性强、润滑性好、储层保护效果好等多种功能;该体系性能稳定,容易维护,很大程度地提高了井壁稳定性,如张海5井三开井段平均井径扩大率仅为5.66%,井径规则,现场进行多次电测和核磁共振测试,均一次成功,建议在该地区进行推广应用.

Applications of the Novel Formate/Positive-charged Polyglycol Drilling Fluid in the South Beach Area

The south beach is one of the main exploration areas at Dagang oilfield. The complex circumstances such as sloughing, lost circulation, unsmooth tripping and instability in mud performance often occurred during drilling operations due to the complicated formation conditions and high salinity of formation brine. In order to realize the safe and rapid well drilling, a new kind of formate/positive-charged polyglycol drilling fluid system has been developed by virtue of utilizing the coordinated effect of formate and positive-charged polyglycol in this study. It is shown from the results of field tests in the wells Zhanghai 5 and Zhanghai 11 that this kind of drilling fluid has multi-functions such as high-temperature stability, anti-sloughing, lubrication and formation damage control. Hence, we suggest applying this drilling fluid system widely in the area.