Chemo-mechanical investigation of CO2-fluid-rock interaction in CO2 storage and CO2-EOR processes in unconventional reservoirs

R. Prakash, P. Kana Nguene, T. D. Seers, A. Noshadravan, S. Abedi

Research output: Contribution to conferencePaper

Abstract

Carbon dioxide (CO2) sequestration is one of the emerging strategies to contain anthropogenic carbon. Successful application of CO2 based Enhanced Oil recovery (EOR) techniques and its storage in unconventional reservoirs requires comprehensive understanding of CO2-fluid-rock interaction. The aim of this study is to characterize the microstructural evolution and chemo-mechanical interaction of shales with CO2 rich brine. Shale assessment, in this case, is focused on the characterization of its constituent phases such as clay, quartz or calcite. Various types of Eagle Ford shales with different compositions have been considered. First, samples are exposed to CO2-rich brine at controlled temperature and pressure conditions. Nano-indentation and Energy Dispersive X-Ray Spectrometry (EDS/EDX) are then used to quantitatively and semi-qualitatively assess the changes in phases and in mechanical properties of the rock samples. Micro-computed tomography (micro-CT) is concurrently used for analyzing the spatial distribution and textural alteration of constituents of shales after reaction. Results have revealed the existence of three regions of starkly different behaviors after CO2 exposure: a dissolution zone, a precipitation zone adjacent to the previous zone followed by a non-reacted zone. In each of these zones, phases present different mechanical properties, and their thickness and location vary with chemical composition and porosity.

Original languageEnglish
Publication statusPublished - 1 Jan 2019
Event53rd U.S. Rock Mechanics/Geomechanics Symposium - Brooklyn, United States
Duration: 23 Jun 201926 Jun 2019

Conference

Conference53rd U.S. Rock Mechanics/Geomechanics Symposium
CountryUnited States
CityBrooklyn
Period23/6/1926/6/19

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ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Prakash, R., Kana Nguene, P., Seers, T. D., Noshadravan, A., & Abedi, S. (2019). Chemo-mechanical investigation of CO2-fluid-rock interaction in CO2 storage and CO2-EOR processes in unconventional reservoirs. Paper presented at 53rd U.S. Rock Mechanics/Geomechanics Symposium, Brooklyn, United States.