Project Summary

In mid-2014, a review of some of the core analysis performed on rock material from the South West Hub (SW Hub) carbon capture and storage site was conducted.

There were still some key uncertainties remaining about the nature of the mechanisms, the causes of the identified fluid-rock interactions, and the extent to which they could impact on the future planning of the SW Hub injection testing. It was observed that the permeability of the Harvey-1 samples would decrease substantially (up to 60%) after undergoing a laboratory core-flooding procedure. Such results could have significant implications for the CO2 injectivity in the future injection wells at the SW Hub.

The overall objectives of this new work includes:

  • the identification and characterisation of the mechanisms behind the previously observed petrophysical variations in the post-flood samples;
  • characterisation of the in-situ geochemical reactions which may occur at the SW Hub;
  • identify the extent of fines migration that occurs, and thus,
  • estimation of the relative contribution of geochemical reaction changes versus fines migration as contributors to changes in porosity and permeability induced by flooding.

Available Reports

Final Report - Fluid rock interactions and their impact- SW Hub

The main conclusions from this final report are as follows:

  • Workflow and techniques used in this project were found to be very effective in achieving the objectives of the study.
  • The chemical reactions between CO2-saturated brine and minerals are found to be quantitatively low.
  • The physical reactions are variable as fines migration confirmed for the majority of the observed petrophysical alterations of the rocks after flooding.
  • Fines migration can block pore-throats and reduce permeability or remove particles from major flow paths to increase pore connectivity and permeability.
  • Harvey Wonnerup Aii facies is highly variable and the differences influence fines migration and permeability change. Such differences are attributed to the diagenetic factors such as cementation (e.g. in Harvey-3 samples clay fines were mobilised similar to Harvey-1 samples, but the fines were flushed out due to pore structure dictated by the degree of cementation).
  • Diagenetic factors control fluid-rock interactions at the pore scale and have a strong effect on their response to the flooding.
Project Name:
Fluid rock interactions and their impact- SW Hub

Research Organisation:
CSIRO, Curtin University

Status:
Completed, 2016

Authors:
Ali Saeedi, Claudio Delle Piane, Lionel Esteban, Ryan Noble, David Gray, Stefan Iglauer, Maxim Lebedev, Linda Stalker

Reference:
7-0314-0233

Research Program: Carbon Transport + Storage
Demonstration: South West Hub, Southern Perth Basin
Research Focus: Capacity, Improved understanding of trapping mechanisms, Rock properties and relative perm

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