Open AccessElectroseismic characterization of lithology and fluid type in the shallow subsurface. Final report, January 15, 1995--January 14, 1997
Author(s) -
Matthijs W. Haartsen,
О. В. Михайлов,
John Queen
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/615659
Subject(s) - porous medium , fluid dynamics , porosity , geology , lithology , permeability (electromagnetism) , reservoir modeling , current (fluid) , mechanics , characterization (materials science) , flow (mathematics) , geophysics , mineralogy , geotechnical engineering , petrology , materials science , chemistry , physics , nanotechnology , biochemistry , oceanography , membrane
The U.S. Department of Energy funded the M.I.T. Earth Resources Laboratory to investigate electroseismic phenomena. Because electroseismic phenomena in fluid-saturated porous media provide geophysicists with a unique opportunity to detect a seismic-wave-generated flow of pore fluid with respect to the porous matrix. The term {open_quotes}electroseismic{close_quotes} describes phenomena in which a seismic wave induces an electrical field or causes radiation of an electromagnetic wave. Electroseismic phenomena take place in fluid-saturated porous rocks, because the pore fluid carries an excess electrical charge. When the charged pore fluid is forced to flow through the rock by pressure gradients within a seismic wave, a streaming electrical current is generated. This electrical current results in charge separation, which induces an electrical field. Measuring this seismic-wave-induced electrical field allows detection of the fluid flow generated by the wave in the porous medium. In turn, detecting the fluid flow allows characterization of fluid transport properties of the medium. The major contribution of our research is in the following three areas: (1) Theory. Theoretical models of various electroseismic phenomena in fluid-saturated porous media were developed. Numerical algorithms were developed for modeling electroseismic measurements in surface (Paper 1 in this report) and VSP (Paper 2) geometries. A closed-form analytical expression was obtained for the logging geometry (Paper 8). The major result is the theoretical models` prediction that porosity, permeability, and fluid chemistry can be characterized using electroseismic measurements; (2) Laboratory Experiments. A number of laboratory experiments were performed in surface (Paper 4), VSP (Paper 4), and logging (Paper 5) geometries. In addition, conversion of electrical energy into seismic energy was investigated (Paper 6), and (3) Field Measurements