Virtual steering of induction tool for determination of formation DIP angle

摘要

A method is disclosed for using a triad induction tool to identify the formation strike and dip angles. The method can be performed in real time. In one embodiment, the method includes: (1) measuring a magnetic coupling between transmitter coils and receiver coils of a tool in the borehole; (2) obtaining from the measured coupling a strike angle between the tool and the formation; (3) applying a rotational transformation to the coupling measurements to correct for the strike angle; and (4) applying a predetermined set of rotational transformations to the coupling to determine coupling term values as a function of rotation angle. A least-squares curve fit or a Hough transform of the derivative of the coupling term values with respect to position may be used to identify the dip angle.