The mechanism and countermeasures of inclined well wellbore instability in Dibei deep coal seam

Abstract The wellbore instability of the deep coal seam has always been a difficult problem limiting drilling engineering in Dibei area Tarim basin, China. Therefore, mechanisms and anticollapse countermeasures are investigated this study. Firstly, microstructure physical chemical properties rock studied to analyze mechanism. In addition, orthogonal cleat model 3 Dimension Distinct Element Code (3DEC) were proposed calculate collapse pressure seam. And we propose method for optimizing well trajectory based on stability. Finally, by plugging material, an anti-collapse fluid seams is designed applied field. results indicate that there many cleats no montmorillonites clay minerals present rocks, indicating mainly mechanically unstable. 3DEC more accurate, can reflect distribution intuitively. reliability these two models demonstrated actual density DB-X01. Furthermore, study confirms blocking-material system stabilization strategy 3% sulfonated asphalt, emulsified calcium carbonate characteristics. rolling recovery rate rheology experiments show new better sealing inhibiting seams. Field testing DT2 prediction findings help understanding mechanism useful safe efficient development area.