SYSTEM AND METHOD FOR ENHANCED VERTICAL RESOLUTION MAGNETIC RESONANCE IMAGING LOGS

摘要

An interpretation method and system for NMR echo-train data in thinly laminated sequences. The invention uses geological information obtained at higher vertical resolution, such as using Electric Micro Imaging, to enhance the vertical resolution of echo-train data, and thus avoids log interpretations in which the hydrocarbon potential of the formation can be misread because low resolution logs tend to provide an average description o f the formation. Such averaging is especially problematic in thinly laminated sequences that consist of highly permeable and porous sand layers and less permeable silt or essentially impermeable shale layers. In a preferred embodiment, using the additional high-resolution formation information one c an estimate the typical T2-spectra of lithological laminae, and significantly enhance the permeability estimate in the laminated sequences. In another aspect the system and method of the preferred embodiment use neural network( s) to further enhance the resolution of a particular log measurement. The metho d and system are applicable to any temporal data from other logging tools, suc h as the thermal neutron decay log and others. The system and method enable proper evaluation of the high potential of thinly laminated formations, whic h may otherwise be overlooked as lowpermeable formations.