ELECTROMAGNETIC ARRAY FOR SUBTERRANEAN MAGNETIC RANGING OPERATIONS

摘要

An electromagnetic array includes a plurality of axially spaced electromagnets deployed in a non-magnetic housing. The array further includes an electrical module, such as a diode bridge, configured to provide an electrical current having a fixed polarity to at least the first electromagnet in the array. The array may be configured to generate a magnetic field pattern having (i) a single magnetic dipole when the array is energized with an electrical current having a first polarity and (ii) at least one pair of opposing magnetic poles when the array is energized with an electrical current having the opposite polarity. The invention provides multiple independent ranging methodologies for determining the relative position between the wellbores.