Description

This example concerns injection of CO₂ into a natural gas storage reservoir aiming at both the sequestration of CO₂ and the cushion gas substitution. The presented study involves a rather straightforward injection strategy and well pattern. Partly, we test whether the strategy allows for a reasonably low mixing between CO₂ and natural gas. We use a synthetic reservoir model that includes a structural trap formed by an anticline. The reservoir is buried at the depth of 1000 m. It is a high-permeability layer of uniform thickness of 25 m. There are two groups of vertical wells placed in the circular patterns. The group located in the centre region of the anticline is used for temporary storage of natural gas. The other group of wells located far from the centre is used only for CO₂ injection. The CO₂-wells are intentionally placed at a distance from the centre to substitute the cushion gas. Here, the high compressibility of supercritical CO₂ can assist the natural gas withdrawal at decreasing average reservoir pressure. We simulate 3 seasons of the natural gas injection and withdrawal.

 

Associated files

File	Version	Description
GAS-STORAGE.RUN	2021.B	Input file for the example simulation of CO2 injection into a natural gas storage reservoir.
GAS-STORAGE-QUARTER.RUN	2021.B	Input file for the example simulation of CO2 injection into a natural gas storage reservoir. This input file is for the same study in a quarter of the original domain.
GAS-STORAGE.GRDECL	-	Formatted grid file.

Screenshots and animated figures

• CO₂ molar fraction in gas, the gas saturation, and the pressure distribution.

References

1. Afanasyev A., Vedeneeva E. 2021 Compositional modelling of multicomponent gas injection into saline aquifers with the MUFITS simulator. J. Nat. Gas Sci. Eng. 94. 103988. DOI:10.1016/j.jngse.2021.103988