The impact of mineral dissolution on drainage relative permeability and residual trapping in two carbonate rocks

Dataset description

Carbon dioxide (CO₂) injection into deep saline aquifers is governed by a number of physico-chemical processes including mineral dissolution and precipitation, multiphase fluid flow, and capillary trapping. These processes can be coupled, however, the impact of fluid-rock reaction on the multiphase flow properties is difficult to study and is not simply correlated to variation in rock porosity. We observed the impact of rock mineral dissolution on multiphase flow properties in two carbonate rocks with distinct pore structures. The Ketton carbonate was an ooidal limestone with a distinct bimodal pore structure whereas the Estaillades limestone was a bioclastic limestone with a wide range of pore sizes. Observations of steady state N₂-water relative permeability and residual trapping were obtained at 100 bars fluid pressure and 22C, with X-ray tomography used to estimate fluid saturation. These tests alternated with steps in which mineral was uniformly dissolved into solution from the rock cores using an aqueous solution with a temperature controlled acid. Eight alternating sequences of dissolution and flow measurement were performed, with on average 0.5% of the mass of the rocks dissolved at each stage. A sequence of mercury injection capillary pressure measurements were conducted on a parallel set of samples undergoing the same treatment to characterize the evolving pore size distribution and corresponding capillary pressure characteristics. Variations in the multiphase flow properties were observed to correspond to the changes in the underlying pore structure. In the Ketton carbonate, dissolution resulted in an increase of the fraction of pore volume made up by the smallest pores and a corresponding increase in the fraction made up by the largest pores. This resulted in a systematic increase in the relative permeability to the nonwetting phase and decrease in relative permeability of the wetting phase. There was also a modest but systematic decrease in residual trapping. In the Estaillades carbonate, dissolution resulted in an increase in the fraction of pore volume made up by pores in the central range of the initial pore size distribution, and a corresponding decrease in the fraction made up by both the smallest and largest pores. This resulted in a decrease in the relative permeability to both the wetting and nonwetting fluid phases and no discernible impact on the residual trapping. In summary, the impact of rock matrix dissolution will be strongly dependent on the impact of that dissolution on the underlying pore structure of the rock. However, if the variation in pore structure can be observed or estimated with modelling, then it should be possible to estimate the impacts on multiphase flow properties.

Constraints

We gratefully acknowledge permission to publish and funding from the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC), provided jointly by Qatar Petroleum, Shell, and Qatar Science & Technology Park. Qatar Petroleum remain copyright owners

Further information

For more information please contact:

Enquiries

Environmental Science Centre, Nicker Hill, Keyworth
Nottingham
NG12 5GG

Tel : +44 (0)115 936 3143
Fax :+44 (0)115 936 3276
Email :enquiries@bgs.ac.uk

Associated dataset(s)

Qatar Carbonates and Carbon Storage Research Centre (QCCSRC)

Dataset details

Author(s) Sam Krevor , qccsrc@imperial.ac.uk
Principal Investigator(s) Sam Krevor
Imperial College London
Language English
Curator British Geological Survey
Supply media/format Dicom; Version:NA
Storage format Not available
Frequency of update not applicable
Start of capture {ts '2016-01-01 00:00:00'} Not known
End of capture {ts '2017-01-01 00:00:00'} 1st January 2017
Online access URL various
Lineage statement The details of the sample preparation and fluid injection strategy can be found in Niu, Krevor. (in review).
Supplementary information Niu, Krevor. (in review)
Constraints
Access constraints intellectualPropertyRights (rights to financial benefit from and control of distribution of non-tangible property that is a result of creativity)
Use constraints intellectualPropertyRights (rights to financial benefit from and control of distribution of non-tangible property that is a result of creativity)
Additional info on constraints We gratefully acknowledge permission to publish and funding from the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC), provided jointly by Qatar Petroleum, Shell, and Qatar Science & Technology Park. Qatar Petroleum remain copyright owners
Contact details
Department Enquiries
Organisation British Geological Survey
Address Environmental Science Centre, Nicker Hill, Keyworth
City Nottingham
County Nottinghamshire
Country United Kingdom
Postcode NG12 5GG
E-mail enquiries@bgs.ac.uk
Telephone +44 (0)115 936 3143
Fax +44 (0)115 936 3276
Keywords
Topic category code (ISO) geoscientificInformation (information pertaining to earth sciences)
Keywords PETROPHYSICS
CARBON CAPTURE AND STORAGE
Keyword source BGS Keyphrases
Spatial details
Spatial Reference System Not available
Dataset extent
Coverage (Lat/Long) North boundary : 
East boundary  : 
South boundary : 
West boundary  : 
Metadata
Metadata language English
Metadata last updated 14th November 2018
Metadata standard compliance NERC profile of ISO19115:2003
Copyright and IPR
The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.