The Geomechanics and the Acoustic Anisotropy of Reservoir Rocks

Abstract

Knowing the mechanical properties (Young’s modulus (E)( ,
Poisson’s Ratio (ν), Shear Modulus (G), Bulk modulus (K) and
compressibility which is the inverse of Bulk modulus) of the rocks
involve in a reservoir, are critical factors for reservoir
characterization). Those properties affect a wide variety of
applications into the petroleum industry; from drilling well planning
and execution to production performance (sand production,
compaction, subsidence, etc) passing through a wide variety of topics
like wellbore stability, well completions and of course reservoir
characterization. For these reasons, the knowledge of these properties
is really valuable for people working in the petroleum industry and of
course working in reservoir characterization.
This study was located in Berea town, Oklahoma, and it was
intended to identify the geomechanical and acoustic properties of a
sandstone sample. The Berea sandstone elastic properties are
characterized using two methods: Quasi static and Dynamic. A
detailed explanation of the sample preparation and the testing
Journal of Petroleum Research & Studies
E 20
procedure is provided. Calculation results for both methods showed
consistent values for the Young’s modulus being around 3,000,000
psi. The Poisson’s Ratio value is between 0.13 and 0.3. This study was
performed in the PoroMechanics Institute (PMI) in the Sarkeys
Energy Center at the University of Oklahoma, USA.
Monitoring equipment was used to obtain all the information
necessary for the proper characterization of the rock. The results of
this work are a good tool that can be used in future simulations such as
hydraulic fracturing treatment, reservoir fluid flow or reserve
estimation.