Abstract: Extended reach well drilling fluid system (BH-ERD system) is a high-performance water base drilling fluid system that combines organic salt brine of high density and high inhibition as base fluid with other additives. The formula of combined organic salt and main additives are determined in the lab; organic salt dosage is 15%~20%, of which all performance indexes are superior to those of conventional potassium salt polymer drilling fluids both at home and abroad. The system has been applied to 12 wells in artificial islands of Chenghai Block One and Two of Dagang Oilfield, with maximum displacement being 3567.55m, maximum deviation being 95.23°, and maxim horizontal displacement to vertical depth (HD/VD) ratio being 2.57, and zero accidents and trouble during drilling. It helps resolve the technical problems like wellbore stability, hole cleaning, and pipe sticking, etc., breaking the monopoly of foreign drilling fluid technology companies, and bringing about significant economic and social results. Now technological specifications for drilling fluid design and wellsite operation of extend reach wells have been worked out, achieving the goal of low cost and localization, and laying technical basis for further application.

Key words: extended reach, drilling fluid system

摘要： 大位移钻井液体系(BH-ERD体系)是以高密度、强抑制、复合有机盐水为配浆基液,配合其他处理剂而形成的高性能水基钻井液体系。室内进行了核心主剂产品及配方研发,形成了复合有机盐加量为15%~20%的钻井液配方,各项性能均优于国内外传统的钾盐聚合物钻井液体系,先后在大港埕海一区、二区人工岛进行了12口井的现场试验,其中最大位移为3567.55m,最大井斜为95.23°,最大水垂比为2.57,没有发生任何事故与复杂。该钻井液体系解决了大位移井钻井施工过程中井壁稳定、井眼净化、润滑防卡等技术难题,打破了国外公司技术垄断的局面,经济效益和社会效益显著,现已形成了大位移钻井液设计、现场施工技术规范,实现了低成本国产化目标,为推广应用奠定了技术基础。

关键词: 大位移, 钻井液体系