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oa Microseismic analysis for kinematic parameters of subsurface permeable flow
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, The 22nd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2018), May 2018, Volume 2018, p.1 - 5
Abstract
In recent years, a method called passive Seismic Emission Tomography (SET) attracts attention in the petroleum industry. SET estimates the subsurface areas of fluid flow where the seismic noise could be generated due to minor pressure fluctuations caused by the flow in the reservoir using seismic data. In this study, we hypothesized that micro seismic waves used in SET contain fluid flow information such as fluid properties, flow channels, or what the phases are immixed in the flow. We tested, with numerical experiments, if the frequency of seismic signals we observe in the application of SET reflects the fluid rate, i.e., a parameter defined by fluid viscosity, differential pressure and a channel shape. In numerical experiments, we simulate the two-phase flow of water-oil flowing through the channel of a pore throat with a narrow segment to see what the frequency of seismic signals generated at the wall of the channel by using the lattice Boltzmann method in a 3D space. Our numerical experiments found that seismic waves of 10 – 30 Hz would be generated when a droplet passes through the pore throat. The seismic frequency depends on the length of the narrow segment and the flow rate. Since it is known that the location of seismic emission could be estimated in the range of resolution defined by seismic observation, our results indicate the possibility to estimate the flow-related parameters as a function of space. We would like to conclude: i) seismic waves observed in SET are generated by the fluid flow ii) observed seismic frequency includes a characteristic parameter defined by the length of narrow segment and the flow velocity.