A New Rotating Magnet Ranging Method for Drilling Twin Parallel Horizontal SAGD Wells

摘要

A new method for determining the distance and direction from a wellbore being drilled to an existing wellbore is disclosed. A permanent magnetic field source is placed on the end of the bit. Two sensor packages detect the alternating magnetic field generated by the source, and this measurement can determine the distance and direction from a wellbore being drilled to an existing wellbore. The method can be used to drill twin parallel horizontal SAGD wells. In the ranging process, the magnetic sub does not need to pass over the measuring tool, so the method needs less time than existing methods need.