Elastic full-waveform inversion of vertical seismic profile data acquired with distributed acoustic sensors
MetadataShow full item record
Distributed acoustic sensing (DAS) is a rapidly developing technology particularly useful for the acquisition of vertical seismic profile (VSP) surveys. DAS data are increasingly used for seismic imaging, but not for estimating rock properties. We have developed a workflow for estimating elastic properties of the subsurface using full-waveform inversion (FWI) of DAS VSP data. Whereas conventional borehole geophones usually measure three components of particle velocity, DAS measures a single quantity, which is an approximation of the strain or strain rate along the fiber. Standard FWI algorithms are developed for particle velocity data, and hence their application to DAS data requires conversion of these data to particle velocity along the fiber. This conversion can be accomplished by a specially designed filter. Field measurements show that the conversion result is close to vertical particle velocity as measured by geophones. Elastic time-domain FWI of a synthetic multioffset VSP data set for a vertical well shows that the inversion of the vertical component alone is sufficient to recover elastic properties of the subsurface. Application of the proposed workflow to a multioffset DAS data set acquired at the CO2CRC Otway Project site in Victoria, Australia, reveals salient subhorizontal layering consistent with the known geology of the site. The inverted VP model at the well location matches the upscaled VP log with a correlation coefficient of 0.85.
Copyright © 2018 Society of Exploration Geophysicists.
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 ...
Li, Ruiping (2002)In most cases of seismic processing and interpretation, elastic isotropy is assumed. However, velocity anisotropy is found to exist in most subsurface media. Hence, there exists a fundamental inconsistency between theory ...