1887

Abstract

Summary

CO2 sequestration involves injection of large volumes of CO2 into a storage reservoir bounded above and below by low-permeability seals. Although capillary effects are usually sufficient to prevent CO2 leakage through the caprock, the native brine will slowly migrate through the over- and underlying units when subject to overpressure in the reservoir. At large scales and over long time periods, diffuse fluid migration may have an important impact on large-scale pressure development.

Typically, simulation studies of CO2 injection often omit the possibility of brine migration through the top and bottom boundaries of the reservoir. One reason is that vertical fluid flow requires additional resolution outside of the storage reservoir that poses a large computational burden. Therefore, analytical methods are an attractive approach for capturing diffuse brine leakage. In low permeability layers, the flow is predominantly vertical, and the local system can be reduced to a 1D (vertical) equation. This can be solved on a semi-infinite (vertical) domain for a thick seal (> 10–20 m), with the reservoir overpressure applied as a boundary condition. Because the boundary condition is not constant in time, the resulting solution is a convolution integral that must be computed at regular time intervals.

In this paper, we couple the analytical solution for vertical brine leakage with a vertical equilibrium simulator (VESA). The VESA simulator is a reduced-dimension (2D) numerical model for two-phase flow in gravity-segregated systems, which is an appropriate assumption for large-scale CO2 storage. Coupling analytical solution for brine migration into a numerical simulator gives greater flexibility modeling injection into heterogeneous reservoirs. We find that the additional computational burden of the convolution integral is minimal compared to solving the full 3D system at the correct resolution. A solution for pressure development in the adjacent strata is also obtained analytically, leading to a fully 3D representation of pressure in the system. The coupled code is benchmarked with a fully analytical solution, and then applied to large-scale CO2 injection into the Utsira formation. We study the impact of diffuse brine leakage on development of large-scale overpressure in the storage reservoir for scenarios of high-volume CO2 injection.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201802270
2018-09-03
2024-03-28
Loading full text...

Full text loading...

References

  1. Birkholzer, J.T., Zhou, Q. and Tsang, C.F.
    [2009] Large-scale impact of CO2 storage in deep saline aquifers: A sensitivity study on pressure response in stratified systems.Int. J. Greenh. Gas Con., 3(2), 181–194.
    [Google Scholar]
  2. Chang, K.W., Hesse, M.A. and Nicot, J.P.
    [2013] Reduction of lateral pressure propagation due to dissipation into ambient mudrocks during geological carbon dioxide storage.Water Resour. Res., 49(5), 2573–2588.
    [Google Scholar]
  3. Collins, R.E.
    [1961] Flow of fluids through porous materials.Van Nostrand Reinhold, New York.
    [Google Scholar]
  4. Eiken, O., Ringrose, P., Hermanrud, C., Nazarian, B., Torp, T.A. and H∅ier, L.
    [2011] Lessons learned from 14 years of CCS operations: Sleipner, In Salah and Snohvit. Energy Procedia, 4, 5541–5548.
    [Google Scholar]
  5. Gasda, S.E., du Plessis, E. and Dahle, H.K.
    [2013] Upscaled models for CO2 injection and migration in geological systems. In: Bastian, P., Kraus, J., Scheichl, R. and Wheeler, M.F. (Eds.) Simulation of flow in porous media: Applications in energy and environment, De Gruyter, 1–38.
    [Google Scholar]
  6. Halland, E., Johansen, W. and Riis, F.
    (Eds.) [2011] CO2 storage atlas: Norwegian North Sea.Norwegian Petroleum Directorate.
    [Google Scholar]
  7. Iglauer, S., Pentland, C.H. and Busch, A.
    [2015] CO2 wettability of seal and reservoir rocks and the implications for carbon geo-sequestration.Water Resour. Res., 51(1), 729–774.
    [Google Scholar]
  8. Kirby, G.A., Chadwick, R.A. and Holloway, S.
    [2001] Depth mapping and characterisation of the Utsira sand saline aquifer, northern North Sea. Commissioned report CR/01/218, British Geological Survey.
    [Google Scholar]
  9. Nordbotten, J.M. and Celia, M.A.
    [2012] Geological storage of CO2: Modeling approaches for large-scale simulation.Wiley.
    [Google Scholar]
  10. Nordbotten, J.M. and Dahle, H.K.
    [2011] Impact of the capillary fringe in vertically integrated models for CO2 storage.Water Resour. Res., 47(2), W02537.
    [Google Scholar]
  11. Pillitteri, A., Cesari, P., Stavrum, J., Zweigel, P. and Boe, R.
    [2003] Rock mechanical tests of shale samples from the cap rock of the Utsira sand in well 15/9-A11. Report 33.5324.00/06/03, SINTEF.
    [Google Scholar]
  12. Singh, V., Cavanagh, A., Hansen, H., Nazarian, B., Iding, M. and Ringrose, P.
    [2010] Reservoir modeling of CO2 plume behavior calibrated against monitoring data from Sleipner, Norway. In: SPE Annual Technical Conference and Exhibition.19 p. SPE 134891.
    [Google Scholar]
  13. Springer, N., H∅ier, C. and Lindgren, H.
    [2002] Mineralogical and petrophysical properties of Utsira sand before and after reaction with CO2 saturated formation water. Report 2002/42, GEUS.
    [Google Scholar]
  14. Springer, N. and Lindgren, H.
    [2006] Caprock properties of the Nordland shale recovered from the 15/9-A11 well, the Sleipner area. In: 8th International Conference on Greenhouse Gas Control Technologies.Elsevier, 1–6.
    [Google Scholar]
  15. Yortsos, Y.C.
    [1995] A theoretical analysis of vertical flow equilibrium.Transport Porous Med., 18(2), 107–129.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201802270
Loading
/content/papers/10.3997/2214-4609.201802270
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error