摘要 |
The methods disclosed herein incorporate the basic concepts and methodologies of a new general rock-bit interaction model useful in predicting and controlling drilling trajectories in directional (and deep vertical) wells. It accounts for the anisotropic drilling characteristics of both the formation and the bit. The model is developed in a 3-D geometry. Therefore, it is capable of predicting the walk tendency and the build/drop tendency of a given BHA (bottomhole assembly) under any drilling condition. The model can be used in the forward mode to predict the drilling direction; in the inverse mode to generate the rock and bit anisotropy indices; and in the log-generation mode to generate drilling logs, such as a drilling dip log. |