A new downhole magnetic resonance imaging tool

Abstract

This paper presents a novel inside-out magnetic resonance imaging (MRI) device with axial, radial and circumferential measurements. The designed MRI probe employs array antenna and phase-controlled transmitters to accomplish spin echo data acquisition. Nuclear Magnetic Resonance (NMR) has been successfully applied to downhole formation evaluation with unique information of in-situ reservoir properties for decades. Traditional NMR logging measurements, however, are averaged the whole sensitive volume. The designed downhole MRI tool overcomes the weakness of traditional technique and raise new applications such as for heterogeneous formation evaluation around well bore and for harsh borehole conditions. We demonstrate the feasibility with a prototype in a calibration tank. The acquired echo trains from different direction and different radial depth are in good quality.