Fluid substitution in shaley sediment using effective porosity
MetadataShow full item record
The traditional method of fluid substitution in porous rock requires the total porosity and the elastic modulus of the mineral phase as input and assumes that the fluid reaches instantaneous hydraulic equilibrium throughout the pore space. This assumption may not be appropriate for shaley sediment because of the low permeability of shale and the resulting immobility of the water in it. To address this problem, we propose an alternative method that uses effective porosity instead of total porosity. Effective porosity is lower than total porosity if porous shale is present in the system. A new, composite mineral phase is introduced, which includes the porous water-saturated shale together with the nonporous minerals and whose elastic modulus is an average of those of its components, including the porous shale. This alternative method increases the sensitivity of the elastic properties of sediment-to-pore-fluid changes and therefore may be used as a physics-based theoretical tool to better explain and interpret seismic data during exploration as well as variations in seismic response as hydrocarbon production progresses.
Published by the Society of Exploration Geophysicists.
Copyright © 2007 Society of Exploration Geophysicists.
The link to the journal’s home page is: http://segdl.aip.org/geophysics/
Showing items related by title, author, creator and subject.
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 ...
Brajanovski, Miroslav (2004)Naturally fractured reservoirs have attracted an increased interest of exploration and production geophysics in recent years. In many instances, natural fractures control the permeability of the reservoir, and hence the ...
Al Hinai, Adnan Saif Hamed; Rezaee, M. Reza (2015)Assessing shale formations is a major challenge in the oil and gas industry. The complexities are mainly due to the ultra-low permeability, the presence of a high percentage of clay, and the heterogeneity of the formation. ...