Mineralogical effects on elastic properties and anisotropies of organic shales
- Xuan Qin (University of Houston) | De-Hua Han (University of Houston) | Fuyong Yan (University of Houston) | Luanxiao Zhao (Tongji University)
- Document ID
- Society of Exploration Geophysicists
- 2016 SEG International Exposition and Annual Meeting, 16-21 October, Dallas, Texas
- Publication Date
- Document Type
- Conference Paper
- 2016. Society of Exploration Geophysicists
- Rock physics, Anisotropy, Shale
- 1 in the last 30 days
- 59 since 2007
- Show more detail
In this study, we investigate the reported ultrasonic measurements of core samples of organic shale and our lab measurements. We focus on Vp/Vs ratios, P-impedance, and velocity anisotropies for different types of organic shales. A layered model is constructed to explain why the silica-rich shales tend to have higher S-wave anisotropy and calcareous shales tend to have higher P-wave anisotropy. The modeling results of the ratio of Thomsen’s anisotropic parameters, γ/ε, remain approximately as constants in the silica-rich and calcareous shales. Hence, γ/ε ratio may be potentially treated as an indicator for mineralogical composition in shale reservoirs. We also observe linear trends between Thomsen’s parameters, ε and δ, in the calcareous shale. Additionally, ν12 and ν31, Poisson’s ratios in a transverse isotropic (TI) medium, exhibit a linear relationship in silica-rich shales and clay-rich shales, providing insights for characterizing mineralogical composition of organic shales.
Presentation Date: Tuesday, October 18, 2016
Start Time: 3:20:00 PM
Presentation Type: ORAL
|File Size||1 MB||Number of Pages||5|
Han,D.,A.Nur, andD.Morgan,1986,Effects of porosity and clay content on wave velocities in sandstones:Geophysics,51,2093–2107,10.1190/1.1442062.
Hart,B.,J.Macquaker, andK.Taylor,2013,Mudstone (shale) depositional and diagenetic processes: Implications for seismic analyses of source-rock reservoirs:Interpretation,1,B7–B26,10.1190/INT-2013-0003.1.
Jakobsen,M., andT. A.Johansen,2000,Anisotropic approximations for mudrocks: A seismic laboratory study:Geophysics,65,1711–1725,10.1190/1.1444856.
Johnston,J., andN.Christensen,1995,Seismic anisotropy of shales:Journal of Geophysical Research,100,5991–6003,10.1029/95JB00031.
Thomsen,L.,1986,Weak elastic anisotropy:Geophysics,51,1954–1966,10.1190/1.1442051.
Vernik,L., andX.Liu,1997,Velocity anisotropy in shales: A petrophysical study:Geophysics,62,521–532,10.1190/1.1444162.