System and method for detecting casing in a formation using current

摘要

The present disclosure is directed to systems and methods for relative positioning of wells. A method in accordance with an exemplary embodiment may include drilling a new well in a field having at least three completed wells using a drilling tool that includes a magnetometer. The method may further include driving current on a first pair of the at least three completed wells and then driving current on a second pair of the at least three completed wells, wherein the current is driven on each of the first and second pairs in a balanced mode. The method may also include measuring a direction of a first magnetic field generated by the current on the first pair using the magnetometer, measuring a direction of a second magnetic field generated by the current on the second pair using the magnetometer, and determining a location of the drilling tool relative to the completed wells based on the direction of the first magnetic field and the direction of the second magnetic field.