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

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