A Study on the Chemo-mechanical Alteration of Cement in CO2 Storage Sites

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

1 Citation (Scopus)

Abstract

The fluid pressure, the stress due to the column of the cement in the annulus of oil and gas wells, and the radial pressure exerted on the cement sheath from the surrounding geological layers all affect the integrity of the cement sheath. This paper studies the impact of CO2-bearing fluids, coupled with the geomechanical alterations within the cement matrix on its integrity. These geochemical and geomechanical alterations within the cement matrix have been coupled to determine the cement lifespan. Two main scenarios including radial cracking and radial compaction, were assumed in order to investigate the behaviour of the cement matrix exposed to CO2-bearing fluids over long periods. If the radial pressure from the surrounding rocks on the cement matrix overcomes the strength of the degraded layers within the cement matrix, cement failure can be postponed, while on the other hand, high vertical stress on the cement matrix in the absence of a proper radial pressure can lead to a reduction in the cement lifespan. The radial cracking process generates local areas of high permeability around the outer face of the cement sheath. Our simulation results show at the shallower depths the cement matrices resist CO2-bearing fluids more and this delays exponentially the travel time of CO2-bearing fluids towards the Earth's surface. This is based on the evolution of CO2 gas from the aqueous phase due to the reduction in the fluid pressure at shallower depths, and consumption of CO2 in the reactions which occur at the deeper locations.
Original languageEnglish
Title of host publicationSociety of Petroleum Engineers - SPE Europec Featured at 81st EAGE Conference and Exhibition 2019
PublisherSociety of Petroleum Engineers
Number of pages19
ISBN (Electronic)9781613996614
ISBN (Print)978-1-61399-661-4
DOIs
Publication statusPublished - Jun 2019
Event81st EAGE Conference and Exhibition: Embracing Change - Creativity for the Future - London, United Kingdom
Duration: 3 Jun 20196 Jun 2019

Publication series

NameSociety of Petroleum Engineers - SPE Europec Featured at 81st EAGE Conference and Exhibition 2019

Conference

Conference81st EAGE Conference and Exhibition
CountryUnited Kingdom
CityLondon
Period3/06/196/06/19

Keywords

  • CO leakage
  • CO storage
  • Cement
  • Cement alteration

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology
  • Fuel Technology

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