大位移井钻井作业的关键技术

KEY TECHNOLOGIES IN THE LARGE EXTENDED REACH DRILLING

沈伟 谭树人

Shenwei Tan Shuren

中海石油技术服务公司技术发展中心, 北京 101149

针对大位移钻井作业中的几个关键技术——降低摩阻技术、井眼清洗技术及井壁稳定技术进行了阐述,通过分析高摩阻、井壁不稳定及洗井效率低等问题产生的原因,认为降低钻井摩阻,不仅取决于钻井液性能、井眼轨迹的优化设计、钻具组合设计、新井下工具的使用,而且也与井壁稳定情况和井眼清洁程度有关。井眼清洁程度则与钻井液性能及其它钻井工程措施息息相关。井壁的稳定取决于钻井液的强抑制能力,钻井液安全密度窗口安全可信,同时也与井眼轨迹有关。综合考虑降低摩阻、井眼清洗和井壁稳定3方面的因素对成功钻大位移井是至关重要的。

This paper describes the several key technologies in e xtended reach dr illing, e.g., friction reduction, hole cleaning and well stabilization. Through the analysis to the mechanisms of high friction, hole instability and poor clean out, it concludes that friction reduction is not depended on the drilling fluid property, optimization of trajectory design, BHA design, use of new tools only, but on hole stabilization condition and cleaning efficiency also. Further more, hole cleaning is closely connected with drilling fluid property and other drilli ng parameters, and hole stabilization is determined by the strong inhibition of drilling fluid, reliable drilling fluid density safety window, and well trajecto ry. It concluded that a comprehensive consideration of friction reduction, hole cleanout and hole stabilization is critical for the successful drilling of an ex tended reach well.

10.3969/j.issn.1000-7393.2000.06.007