JOURNAL: Feldspar alteration by disequilibrium CO2-H2O fluids in reservoir sandstones: implications for CCS
Summary
Authors:
Natalie J. C. Farrell
Lining Yang
Michael J. Flowerdew
Chris Mark
Buhari Ardo
Kevin G. Taylor
Nico Bigaroni
Michael Pointon
Lewis Hughes
John Waters
Lee Paul
University of Manchester
Institute of Marine Sciences (CNR-ISMAR)
CASP
Swedish Museum of Natural History
University College Dublin
Feldspar alteration by disequilibrium CO2-H2O fluids in reservoir sandstones: implications for CCS
Solid Earth
March 2026
This paper investigates how feldspar, one of the most common minerals in reservoir rocks, reacts when exposed to CO2-rich fluids during carbon storage. Using lab experiments on sandstone from the Captain Sandstone Member (the reservoir for the Acorn CCS Project), researchers tested a range of pressures and temperatures to mimic underground conditions. They found that CO2 causes feldspar grains to weaken, dissolve, and sometimes reform as new minerals, changing the rock’s internal structure. These changes could affect how fluids flow through the reservoir and raise the risk of instability, highlighting the need for closer study of feldspar behaviour in CCS projects.