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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/130/0176

    • Keywords

       

      Rock properties; triaxial testing; ultrasonic measurements; mechanical Earth model; Mumbai oAshore.

    • Abstract

       

      The characterization of the reservoir rock's geomechanical properties is critical to address wellbore instabilities and subsidence-related issues. To address these issues, lab-derived dynamic and static elastic properties are essential to match the in-situ rock properties. In this study, as part of a new integrated workflow P-wave and S-wave velocities are congregated using ultrasonic transducers for the core plugs, which constitutes mainly carbonates, shales, and both. Mineral composition, shale anisotropy, seismic velocities, and cross plots are studied to understand shear wave splitting. During this study, as a part of 1D mechanical Earth models, rock elastic properties are calculated for 60 wells using petrophysical logs (gamma, density, acoustic and caliper). Also, triaxial loading tests are conducted on 14 specimens collected from the same wells, static Poisson's ratio and static Young's modulus are computed from the stress-strain curves. The major differences are observed between static and dynamic elastic properties calculated from well logs and lab tests. Cohesion and friction angle for rock samples are estimated from the triaxial tests under different confining pressures. The objective of this study is to compare the elastic properties derived from the ultrasonic method with well logs and fill the gaps in the 1D geomechanical model. The combined analysis of elastic properties from different methods provides exciting insights on wellbore stability in anisotropic rock.

    • Author Affiliations

       

      VENKATESH AMBATI1 SHASHANK SHARMA1 M NAGENDRA BABU1 RAJESH R NAIR1

      1. Petroleum Geomechanics Laboratory, Indian Institute of Technology Madras, Chennai, India.
    • Dates

       
  • Journal of Earth System Science | News

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      Posted on July 25, 2019

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