Design and Implementation of a Robust NMR Fluid Analyzer with Multiple Antennas

Abstract

During last 20 years, nuclear magnetic resonance (NMR) fluid analyzer is becoming a usual instrument to conduct researches to fluids several thousand meters underground in real time due to its nondestructive, rapid, and repeatable characteristics. In this paper, a new set of down-hole NMR fluid analyzer was designed and implemented. The probe of the analyzer employs special ring-shaped magnets which can be fastened to a high permeability material with a card slot. This design can decrease the twist between adjacent magnet blocks and obtain a homogeneous magnetic field. Meanwhile, in the axis direction, a stabilization section was added to the polarized magnets for improving the polarization efficiency. Furthermore, the system adopts a multiple antenna structure, by which it can achieve multi-parameter and multi-function measurements. To match with the antenna structure, an antenna control module was put to the circuit system to quickly switch the working antenna. Then, the performance of this new designed system was validated by both stationary and flow fluid. In the future, the analyzer can be combined with the formation tester for down-hole fluid analysis or used independently for ground fluid analysis during oil exploitation and transportation.