Patent ID: 8581587

Claim:
A Surface Nuclear Magnetic Resonance (SNMR) method, comprising: arranging one or more induction coils on the surface of the Earth; transmitting two or more electrical current pulse sequences on the induction coils, wherein each of the transmitted pulse sequences are associated with a single NMR measurement, wherein each of the transmitted pulse sequences comprises one or more oscillating electrical current pulses, and wherein each of the oscillating electrical current pulses has a phase of oscillation relative to the other oscillating electrical current pulses in the two or more transmitted pulse sequences; applying a phase shift to at least one of the transmitted oscillating electrical current pulses in at least one of the transmitted pulse sequences, wherein the applied phase shift is relative to a phase of at least one of the transmitted oscillating electrical current pulses in another of the transmitted pulse sequences; detecting signals on the induction coils after and/or during each of the electrical current pulse sequences; and linearly combining detected signal data corresponding to separate electrical current pulse sequences to produce combined signal data in which one or more detected signal components are preserved and one or more different detected signal components are reduced or cancelled.