An estimation of sonic velocities in shale using clay and silt fractions from the elemental capture spectroscopy log
MetadataShow full item record
Anisotropic differential effective medium approach is used to simulate elastic properties of shales from elastic properties and volume fractions of clay and silt constituents. Anisotropic elastic coefficients of the wet clay pack are assumed to be independent of mineralogy and to be linearly dependent on clay packing density (CPD), a fraction of clay in an individual wet clay pack. Simulated compressional and shear velocities normal to the bedding plane and are shown to be in a good agreement with measured sonic velocities. Further, elastic coefficients of shales, and, calculated from the log sonic velocities, calibrated porosity and clay fraction obtained from the mineralogy tool are used to invert for elastic constants of clays, C33 and C44. The obtained elastic coefficients of clays show lower scatter than the original elastic coefficients of shales. The noticeable increase of the clay elastic coefficients with the depth increase is shown to result from the positive trend of the CPD with depth. Being interpolated to the same CPD = 0.8, elastic coefficients of clays show no depth dependency. Our findings show that the CPD and silt fraction are the key parameters that can be used for successful modelling of elastic properties of shales.
Showing items related by title, author, creator and subject.
Prediction of sonic velocities in shale from porosity and clay fraction obtained from logs - A North Sea well case studyPervukhina, Marina; Golodoniuc, P.; Gurevich, Boris; Clennell, M.; Dewhurst, D.; Nordgård-Bolås, H. (2014)Prediction of sonic velocities in shales from well logs is important for seismic to log ties if the sonic log is absent for a shaly section, for pore pressure anomaly detection, and for data quality control. An anisotropic ...
Investigation of pressure and saturation effects on elastic parameters: an integrated approach to improve time-lapse interpretationGrochau, Marcos Hexsel (2009)Time-lapse seismic is a modern technology for monitoring production-induced changes in and around a hydrocarbon reservoir. Time-lapse (4D) seismic may help locate undrained areas, monitor pore fluid changes and identify ...
Compaction of quartz-kaolinite mixtures: The influence of the pore fluid composition on the development of their microstructure and elastic anisotropyBeloborodov, R.; Pervukhina, M.; Luzin, V.; Delle Piane, C.; Clennell, M.; Zandi, S.; Lebedev, Maxim (2016)Shales play important roles in sedimentary basins, acting as both seals and reservoir rocks, and knowledge of their anisotropic velocity trends is of practical importance for correct seismic image processing and inversion, ...