FIELD: physics; geophysics.
SUBSTANCE: invention relates to geophysics and can be used in prospecting for oil and natural gas. The electromagnetic array includes a plurality of axially arranged electromagnets placed in a nonmagnetic 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 a single magnetic dipole when the array is energised with an electrical current having a first polarity and at least one pair of opposing magnetic poles when the array is energised with an electrical current having the opposite polarity. The invention provides multiple independent ranging methods for determining the relative position between the wellbores.
EFFECT: high accuracy of subterranean magnetic ranging operations.
12 cl, 10 dwg
