Abstract: The evaluation of drillability anisotropy and deflecting characteristics of formation is very important for directional drilling and deviation control of horizontal well. The correlation of rock drillability in perpendicular and parallel directions of the bedding plane of core samples was analyzed by means of mathematical statistics. A mathematic model was established and applied to prediction of drillability in parallel direction to the bedding plane of formation by using drillability in perpendicular direction to the bedding plane of formation. Thus the mathematic model can predict anisotropy of drillability by using rock drillability in perpendicular direction to the bedding plane of formation. The rock anisotropic parameters were inversed by using well-log information, and acoustic wave velocity in perpendicular direction to the bedding plane of a formation was calculated by using acoustic wave velocity in any direction of the bedding plane of a formation. The rock drillability in perpendicular direction of the bedding plane in a formation can be calculated by using acoustic wave velocity in the same direction. The evaluation methods for drillability and deflecting characteristics of anisotropy formation by using well-log information as input were used to estimate the drillability anisotropy and deflecting characteristics of formation with high stratigraphic dip in Kelasu area of Tarim Basin. The result shows that anisotropy indexes of formation drillability assessed by this method can properly reflect the strata-drifting characteristics of the evaluated formation.

Key words: well-log information, rock drillability, anisotropy, deflecting characteristics, hole deviation control, evaluation method

摘要： 地层可钻性各向异性及造斜特性评价对定向钻井和直井防斜均具有重要意义。用数理统计的方法分析了垂直于层面和平行于层面岩石可钻性的相关关系,用垂直于层面岩石可钻性的评价方法评价了平行于层面岩石可钻性,由此导出根据垂直于层面岩石的可钻性评价地层可钻性各向异性的模型。根据声波在横观各向同性介质中的传播规律,建立了利用测井资料反演岩石的各向异性参数进而求取垂直于层面声波波速的方法。由垂直于层面方向的声波速度计算出垂直于岩石层面方向的岩石可钻性,从而可以对地层可钻性各向异性及造斜特性进行评价。对塔里木油田克拉苏地区的造斜特性的评价结果表明:用该方法评价出的地层可钻性各向异性及造斜特性能正确反映被评价地层的特性。

关键词: 测井资料, 岩石可钻性, 各向异性, 造斜特性, 井斜控制, 评价方法