扩眼尺寸在不同工况下的影响分析——以准噶尔盆地南缘H101井为例

Analysis of the Effects for Reamer Size under Different Operation Conditions:a Case Study of Well H101 in the Southern Margin of Junggar Basin

扩眼尺寸参数的确定是国内外扩眼研究的难点。为了保障在扩眼段顺利钻井和固井,以准噶尔盆地南缘H101井为例,深入研究扩眼尺寸在钻进、起下钻以及固井工况下的影响规律。从钻具弯曲变形、排量优化、底部钻具组合振动、起下钻抽吸激动压力与密度窗口、下尾管激动压力、注水泥当量循环密度(ECD)、以及考虑井眼曲率的井筒完整性角度分析其对扩眼尺寸的要求,并讨论下入套管尺寸变更对扩眼段固井的影响,最后结合数理统计分析综合考虑确定扩眼尺寸参数值。准噶尔盆地南缘H101井及同类井应用扩眼尺寸参数进行扩眼均顺利完钻,并且H101井扩眼段实现单日进尺101 m。提出的优选扩眼尺寸的方法和思路考虑因素更全面、更有说服力,对扩眼井确定扩眼尺寸具有重要借鉴意义。

The determination of the reamer size(the desirable reamed borehole size)is a global challenge for research on reaming in drilling.To ensure smooth drilling and cementing of reamed borehole sections,an in-depth case study of Well H101 drilled in the southern margin of Junggar Basin was performed to identify the affecting patterns of the reamed borehole size on drilling,tripping and cementing operations.The requirements for the reamer size were analyzed from perspectives of the drilling tool bending deformation,pump rate optimization,BHA vibration,swab and surge pressure during tripping and fluid density window,surge pressure of running liners,equivalent circulating density(ECD)during cementing,and wellbore integrity incorporating wellbore curvature,and the impacts of changes in casing sizes on cementing of the reamed borehole section were investigated.Finally,the above analyses were combined with a mathematical statistical approach to comprehensively determine the reamer size.The determined reamer size was applied to Well H101 and analogous wells in the southern margin of Junggar Basin,which were all found with smooth drilling operations after reaming,and moreover,Well H101 delivered a daily penetration of 101 m for the reamed borehole section.The presented method and strategy for the reamer size optimization incorporate more factors and are more reliable.They provide important references for determining the reamer size of to-be-reamed wells.