On the Significance of Hydrate Formation/Dissociation during CO2 Injection in Depleted Gas Reservoirs

V. Indina, B. R.B. Fernandes, M. Delshad, R. Farajzadeh, K. Sepehrnoori

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review


The study aims to quantitatively assess the risk of hydrate formation within the porous formation and its consequences to injectivity during storage of CO2 in depleted gas reservoirs considering low temperatures caused by the Joule Thomson (JT) effect and hydrate kinetics. The aim was to understand which mechanisms can mitigate or prevent the formation of hydrates. The key mechanisms we studied included water dry-out, heat exchange with surrounding rock formation, and capillary pressure. A compositional thermal reservoir simulator is used to model the fluid and heat flow of CO2 through a reservoir initially composed of brine and methane. The simulator can model the formation and dissociation of both methane and CO2 hydrates using kinetic reactions. This approach has the advantage of computing the amount of hydrate deposited and estimating its effects on the porosity and permeability alteration. Sensitivity analyses are also carried out to investigate the impact of different parameters and mechanisms on the deposition of hydrates and the injectivity of CO2. Simulation results for a simplified model were verified with results from the literature. The key results of this work are: (1) The Joule-Thomson effect strongly depends on the reservoir permeability and initial pressure and could lead to the formation of hydrates within the porous media even when the injected CO2 temperature was higher than the hydrate equilibrium temperature, (2) The heat gain from underburden and overburden rock formations could prevent hydrates formed at late time, (3) Permeability reduction increased the formation of hydrates due to an increased JT cooling, and (4) Water dry-out near the wellbore did not prevent hydrate formation. Finally, the role of capillary pressure was quite complex, where it reduced the formation of hydrates in certain cases and increased in other cases. Simulating this process with heat flow and hydrate reactions was also shown to present severe numerical issues. It was critical to select convergence criteria and linear system tolerances to avoid large material balance and numerical errors.

Original languageEnglish
Title of host publicationSPE Conference at Oman Petroleum and Energy Show, 2024
PublisherSociety of Petroleum Engineers
Number of pages21
ISBN (Electronic)9781959025252
Publication statusPublished - 2024
EventSPE Conference at Oman Petroleum and Energy Show, 2024 - Muscat, Oman
Duration: 22 Apr 202424 Apr 2024

Publication series

NameSociety of Petroleum Engineers - SPE Conference at Oman Petroleum and Energy Show, OPES 2024


ConferenceSPE Conference at Oman Petroleum and Energy Show, 2024
Abbreviated titleOPES 2024

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • Carbon Capture and Storage
  • CO Hydrate
  • Depleted Gas Reservoirs
  • Joule-Thomson Effect
  • Thermal Reservoir Simulation


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