METHOD OF PREDICTING AND CONTROLLING THE DRILLING TRAJECTORY IN DIRECTIONAL WELLS

摘要

-37-Abstract of the DisclosureThe methods disclosed herein incorporate the basicconcepts and methodologies of a new general rock-bitinteraction model useful in predicting and controllingdrilling trajectories in directional (and deep vertical)wells. It accounts for the anisotropic drillingcharacteristics of both the formation and the bit. Themodel is developed in a 3-D geometry. Therefore, it iscapable of predicting the walk tendency and the build/droptendency of a given BHA (bottomhole assembly) under anydrilling condition. The model can be used in the forwardmode to predict the drilling direction; in the inverse modeto generate the rock and bit anisotropy indices; and in thelog-generation mode to generate drilling logs, such as adrilling dip log.