HR: 1340h
AN: T33C-1508 [Abstracts]
TI: The Acoustic Signature of Woodford Shale and Upscale Relationship from Nano-Scale Mechanical Properties and Mineralogy
AU: Tran, M H
EM: tranhaminh83@ou.edu
AF: University of Oklahoma, 100 East Boyd St.
Suite P119, Norman, OK 73019, United States
AU: * Abousleiman, Y N
EM: yabousle@ou.edu
AF: University of Oklahoma, 100 East Boyd St.
Suite P119, Norman, OK 73019, United States
AU: Hoang, S K
EM: sonhoang@ou.edu
AF: University of Oklahoma, 100 East Boyd St.
Suite P119, Norman, OK 73019, United States
AU: Ortega, A J
EM: ortega@MIT.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139-
4307, United States
AU: Bobko, C
EM: cbobko@MIT.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139-
4307, United States
AU: Ulm, F
EM: ulm@MIT.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139-
4307, United States
AB:
The complex composition of shale, the most encountered and problematic lithology in the Earth's crust, has
puzzled many researchers attempting to find the key for understanding their micro- and macro-scale acoustic and
mechanical signatures. Recent advances in nano-technology, in particular the progress of the Atomic Force
Microscope (AFM) base indentation technique, have made it possible to mechanically study porous material at a
nano scale (10-9 m) and consequently have allowed linking shale mechanical properties to intrinsic micro-
and macro-properties such as porosity, packing density, and mineralogy. Based on more than 20,000 nano-
indentation tests conducted on a number of shales with varying physical properties, a GeoGenomeTM
model was developed to upscale macroscopic shale mechanical parameters from mineralogy composition,
porosity, and packing density.
In this work, the mechanical properties such as the elastic stiffness coefficients, Cij, and the anisotropic
Biot's Pore Pressure Coefficients, αij, of the Woodford shale, were acquired using sonic log data and
Ultra-Sonic Pulse Velocity (UPV) measurements conducted on preserved retrieved shale core samples from a
200-ft well drilled in the Woodford formation, in Oklahoma. Furthermore, the dependency of the Cij and
αij, on applied stresses and the relationship between the dynamic moduli and the quasi-static moduli
were also investigated using an array of piezoelectric crystals mounted around the samples while subjecting the
samples to different applied stress states using a series of tri-axial tests. X-Ray Diffraction (XRD) and mercury
injection tests were also performed on the retrieved core samples to obtain mineralogy composition and porosity
of the shale at different depths.
Comparison of the simulated mechanical and poromechanical properties and stiffness coefficients using the
Quantitative GeoGenomeTM Mineralogy Simulator (QGGMSTM) with field and acoustic lab
measurements showed excellent agreement both qualitatively and quantitatively. The results from field sonic and
petrophysical logs, laboratory UPV measurements, and the QGGMSTM model show that despite a relatively
high quartz and pyrite content as revealed by the XRD, the Woodford shale does possess clear transverse
isotropic macro-mechanical characteristics as reflected through the Thomsen parameters.
DE: 5102 Acoustic properties
DE: 5194 Instruments and techniques
SC: Tectonophysics [T]
MN: 2007 Fall Meeting