Abstract
CO2 storage with enhanced gas recovery (CSEGR) technology is a pivotal solution to mitigate the greenhouse
effect and respond to national energy conservation and emission reduction policies. This involves injecting CO2
into gas reservoirs for storage and using it to displace gas into producing wells to enhance production. This paper
provides a comprehensive analysis of the primary mechanisms of CO2 storage in gas reservoirs, quantifies the
long-term contribution of these, and summarizes the methods used to evaluate CO2 storage potential. The
mechanisms of the displacement of natural gas by CO2 are explained and two technical difficulties are addressed:
the degree of CO2-natural gas mixing and competitive adsorption and displacement of CO2-CH4. Besides, the
main factors affecting CSEGR are studied thoroughly, and the currently typical CSEGR field pilot tests across the
word are considered along with CSEGR economic policy research. This paper then identifies the current challenges
and future trends in CSEGR development. The results show, firstly, in the later stage of gas reservoir
development, high rates of CO2 injection at the bottom of the gas reservoir and CH4 production at the top can
significantly enhance gas recovery. Secondly, in previous studies, the degree of CO2-natural gas mixing has been
studied more in sandstones and carbonates, while CO2-CH4 competitive adsorption has been studied more in
shales and coal seams. The results of all these studies demonstrate the feasibility of CSEGR. Thirdly, Four major
storage mechanisms interact to stabilize CO2 storage in gas reservoirs, but there is no systematic method to
evaluate the CO2 storage potential. Finally, among recent experimental and simulation studies, CSEGR analytic
techniques that consider complex formation conditions need to be further explored. Additionally, combining
CSEGR with geothermal
effect and respond to national energy conservation and emission reduction policies. This involves injecting CO2
into gas reservoirs for storage and using it to displace gas into producing wells to enhance production. This paper
provides a comprehensive analysis of the primary mechanisms of CO2 storage in gas reservoirs, quantifies the
long-term contribution of these, and summarizes the methods used to evaluate CO2 storage potential. The
mechanisms of the displacement of natural gas by CO2 are explained and two technical difficulties are addressed:
the degree of CO2-natural gas mixing and competitive adsorption and displacement of CO2-CH4. Besides, the
main factors affecting CSEGR are studied thoroughly, and the currently typical CSEGR field pilot tests across the
word are considered along with CSEGR economic policy research. This paper then identifies the current challenges
and future trends in CSEGR development. The results show, firstly, in the later stage of gas reservoir
development, high rates of CO2 injection at the bottom of the gas reservoir and CH4 production at the top can
significantly enhance gas recovery. Secondly, in previous studies, the degree of CO2-natural gas mixing has been
studied more in sandstones and carbonates, while CO2-CH4 competitive adsorption has been studied more in
shales and coal seams. The results of all these studies demonstrate the feasibility of CSEGR. Thirdly, Four major
storage mechanisms interact to stabilize CO2 storage in gas reservoirs, but there is no systematic method to
evaluate the CO2 storage potential. Finally, among recent experimental and simulation studies, CSEGR analytic
techniques that consider complex formation conditions need to be further explored. Additionally, combining
CSEGR with geothermal
| Original language | English |
|---|---|
| Article number | 128555 |
| Number of pages | 18 |
| Journal | Fuel |
| Volume | 349 |
| Publication status | Published - 18 May 2023 |