Resumé
As part of the project Greensand, a CO2 -flooding experiment, Exp-1, was conducted on samples from the Nini-4 well at reservoir conditions (60 °C, 200 bara). The experiment consists of a complex sequence of CO2 and formation brine injection operations aimed at investigating possible reactions between supercritical CO2, formation brine, and the greensand reservoir rock.
The brine permeability measurements agree with the gas permeability determinations of the core samples and gives some information of the brine-CO2 relative permeability relationship.
The measured permeability to CO2 is generally lower than the permeability to brine. A sharp drop in permeability was recorded in the third CO2 flooding operation, which is interpreted as blockage by fines at the outflow end of the core sample. Reversing the flow directions removed the blockage. Apart from this, no permeability anomalies were recorded.
Preliminary investigation of the core sample after the experiment does not reveal significant changes to the greensand rock.
In future project Greensand CO2-flooding experiments, attempts will be made to avoid blocking by fines at the ends of the core sample.
The experimental flow experiment presented here, together with experiments conducted during “Phase 0”, test the mechanical stability of the reservoir. Together with geochemical stability tests obtained during prolonged exposure of reservoir rocks to CO2 saturated brine, they aim at documenting the reservoir compatibility to CO2.
The brine permeability measurements agree with the gas permeability determinations of the core samples and gives some information of the brine-CO2 relative permeability relationship.
The measured permeability to CO2 is generally lower than the permeability to brine. A sharp drop in permeability was recorded in the third CO2 flooding operation, which is interpreted as blockage by fines at the outflow end of the core sample. Reversing the flow directions removed the blockage. Apart from this, no permeability anomalies were recorded.
Preliminary investigation of the core sample after the experiment does not reveal significant changes to the greensand rock.
In future project Greensand CO2-flooding experiments, attempts will be made to avoid blocking by fines at the ends of the core sample.
The experimental flow experiment presented here, together with experiments conducted during “Phase 0”, test the mechanical stability of the reservoir. Together with geochemical stability tests obtained during prolonged exposure of reservoir rocks to CO2 saturated brine, they aim at documenting the reservoir compatibility to CO2.
Originalsprog | Engelsk |
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Udgivelsessted | Copenhagen |
Forlag | GEUS |
Antal sider | 17 |
DOI | |
Status | Udgivet - 10 jan. 2021 |
Publikationsserier
Navn | Danmarks og Grønlands Geologiske Undersøgelse Rapport |
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Nummer | 54 |
Vol/bind | 2020 |
Emneord
- Denmark
Programområde
- Programområde 3: Energiressourcer