The Geomechanics and the Acoustic Anisotropy of Reservoir Rocks

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 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.