DISTANCE DETERMINATION FROM A MAGNETICALLY PATTERNED TARGET WELL

摘要

Methods for determining the distance and relative axial position between twin and target wells are disclosed. In one exemplary embodiment the magnitude and direction of the interference magnetic field vector are processed to determine the distance and the axial position. In another exemplary embodiment, a change in direction of the interference magnetic field vector between first and second longitudinally spaced magnetic field measurements may be processed to determine the distance and axial position. In still another exemplary embodiment of the invention, a component of the magnetic field vector aligned with the tool axis may be measured in substantially real time during drilling and utilized to determine the distance between the two wells. Embodiments of this invention improve the accuracy and/or the frequency of distance determination between twin and target wells.