Applications of a New-Generation NMR Wireline Logging Tool

Abstract

Abstract This paper discusses applications of a new-generation, nuclear magnetic resonance (NMR) wireline logging tool. The new design is a multi-frequency, eccentered, gradient-field NMR logging tool with multiple depths of investigation, which are maintained regardless of the hole size and are deeper than those of previous NMR logging tools. The new-generation tool features a high-resolution acquisition mode, making it possible to perform both fluid characterization and thin-bed analysis. We present the results of MRF* Magnetic Resonance Fluid characterization logging in a range of different environments. MRF acquisition modes comprise suites of spin-echo sequences having sensitivity to molecular diffusion. Simultaneous analysis of an entire suite of data provides depth logs of oil viscosity and fluid saturations measured in the nearwellbore region as well as total porosity, T2 distributions, and permeability estimates. Several logs acquired in different formations are used to demonstrate the high-resolution capability of the new tool. Data acquired in a test well with known characteristics are used to validate the vertical resolution, precision, and accuracy of the measurements.