FIELD TEST OF AN EXPERIMENTAL NMR LWD DEVICE

摘要

An experimental prototype of the Magnetic Resonance While Drilling tool (MRWD) underwent a successful field test campaign during the summer of 1999. The tool accumulated 130 hours of downhole use, including periods of harsh drilling conditions. The hardware was designed to be compatible with the MRIL wireline devices at the data processing and interpretation level. The testing program included the acquisition of conventional triple-combo and MRIL wireline logs. MRWD was run while drilling and after drilling, while stationary, and during sliding and tripping operations. The comparison of wireline MRIL and MRWD data shows that the MRWD provides source-free porosity, free-fluid volume and permeability data. The after-drilling data acquisition mode of MRWD replicates all the essential aspects of the MRIL wireline log. This paper examines the design considerations for acquiring magnetic resonance data in an LWD environment, describes the hardware used in the field test, and includes an analysis of the collected field test data.