Method and System for Detection of a Material within a Region of the Earth

摘要

Methods and systems for detecting a material within a region of the Earth are provided. The region may be under a surface of earthen formation, ice, snow, or water. The method may be practiced in a variety of applications, for example in an arctic region to detect oil spills, leaks, or seepages. The methods and systems may include using at least one coil to transmit a radio frequency (RF) excitation signal into the region of the Earth; and receive any NMR response signals to determine the presence of the material of interest.

主权项

1. A method of detecting a first material in the presence of a second material within a region of interest in the Earth comprising:
transmitting a first inversion radio frequency (RF) excitation signal with at least one coil in the presence of a static magnetic field, the excitation signal sufficient to invert magnetization vectors of both the first and second material in an inversion region within the region of interest such that a plurality of magnetization vectors of the first and second material are substantially aligned with the negative (−) z axis; transmitting a second RF excitation signal with the at least one coil such that the NMR signal from the second material is selectively suppressed in a detection region a given distance remote from the at least one coil; and receiving any NMR signal of the first material generated by the second RF excitation signal originating from the detection region.