What's new in MWD and formation evaluation. [Measurement while drilling (MWD)]

Formation evaluation provides information for characterizing reservoir properties. This paper discusses the recent developments in formation evaluation and includes: new elemental analysis logs to determine fluid saturations and other rock properties; array induction logs for better formation resistivity measurements; a new combination spectral density, neutron and spectral gamma ray log for porosity and lithology determination; dipole acoustic logs to obtain shear wave velocity measurements in acoustically slow rock; a resistivity imaging log with more borehole wall circumferential coverage; more versatile nuclear magnetism logs that do not require borehole fluid modification; slimhole wireline logging tools for quantitative evaluation of small diameter wellbores; a new sophisticated modular wireline test tool; more powerful computing capabilities on wireline logging surface units; x-ray computerized tomography (CT) and nuclear magnetic resonance (NMR) scanning of cores to obtain porosity, fluid saturation and other rock property information; mini-permeameters to take closely spaced permeability measurements on rock faces; mineral analysis by Fourier Transform Infrared Spectroscopy; microscopic and macroscopic core image analysis; quantitative fluorescence analysis of hydrocarbon shows; new measurement while drilling logs for porosity, borehole shape and size, and multi-depth of investigation formation resistivity measurements. Latest developments include new versatile wireline logs and test tools, powerful computers in loggingmore » surface units, more sophisticated MWD logs, better core and cuttings analysis methods, and a CD-ROM catalog of rock properties.« less