Skip navigation
Skip navigation
Open Research will be down for maintenance between 8:00 and 8:15 am on Tuesday, December 1 2020.

Electrostatics and the low salinity effect in sandstone reservoirs

Brady, Patrick V.; Morrow, Norman R.; Fogden, Andrew; Deniz, Vivianne; Loahardjo, Nina; Winoto, Null

Description

There is widespread interest in improved oil recovery by the low salinity effect (LSE) and a pressing need to better predict the likely response and its relation to wettability change. A LSE in kaolinite-bearing sandstones can arise from detachment of crude oil, by its peeling from rock surfaces due to increased oil/rock repulsion, and/or by detachment of mineral fines with adhering oil, due to increased fines/rock repulsion. In a mixed wet sandstone reservoir, oil is typically in close contact...[Show more]

dc.contributor.authorBrady, Patrick V.
dc.contributor.authorMorrow, Norman R.
dc.contributor.authorFogden, Andrew
dc.contributor.authorDeniz, Vivianne
dc.contributor.authorLoahardjo, Nina
dc.contributor.authorWinoto, Null
dc.date.accessioned2015-03-15T22:12:05Z
dc.date.available2015-03-15T22:12:05Z
dc.identifier.issn0887-0624
dc.identifier.urihttp://hdl.handle.net/1885/12932
dc.description.abstractThere is widespread interest in improved oil recovery by the low salinity effect (LSE) and a pressing need to better predict the likely response and its relation to wettability change. A LSE in kaolinite-bearing sandstones can arise from detachment of crude oil, by its peeling from rock surfaces due to increased oil/rock repulsion, and/or by detachment of mineral fines with adhering oil, due to increased fines/rock repulsion. In a mixed wet sandstone reservoir, oil is typically in close contact with an extremely small fraction of total rock surface, a key component of which are asperity tips such as at edges of kaolinite platelets. An Integrated pH Ion Surface Electrostatics (IpHISE) model is used to predict speciation and interactions of oil surfaces and kaolinite edges across NaCl and CaCl2 solutions of variable pH in sandstones. At pH < 5, a LSE can arise by weakened oil adhesion due to fewer positively charged oil base groups adsorbed to kaolinite edges. At higher pH, the electrostatics is dictated by competition between negatively and positively charged acid groups produced by respectively deprotonation and calcium binding. The LSE is predicted to be strongest in a narrow range around pH 5–6 in which salinity reduction switches the oil/kaolinite edge interaction to repulsive. At pH > 6, the interaction becomes increasingly repulsive at all salinities. There, a LSE can only arise from the extended range of repulsion, both between oil and kaolinite edges and between the latter and the underlying rock. The existence and cutoff values of these pH ranges depend sensitively upon the oil’s acid number/base number, salt concentrations, and the pH shift caused by injection of low salinity fluid.
dc.description.sponsorshipFunding from the Sandia National Laboratories LDRD program is appreciated. A.N.U. thanks the member companies of the DigiCore Consortium and Wettability Satellite for funding. Support at UW was provided by Chevron, BP, and Statoil, the Wold Chair, and the University of Wyoming Enhanced Oil Recovery Institute.
dc.format12 pages
dc.publisherAmerican Chemical Society
dc.rights© 2015 American Chemical Society
dc.sourceEnergy & Fuels
dc.subjectoil recovery
dc.subjectlow salinity effect (LSE)
dc.subjectkaolinite-bearing sandstones
dc.subjectIntegrated pH Ion Surface Electrostatics (IpHISE) model
dc.subjectsandstones
dc.titleElectrostatics and the low salinity effect in sandstone reservoirs
dc.typeJournal article
local.identifier.citationvolume29
dc.date.issued2015
local.identifier.absfor029904 - Synchrotrons; Accelerators; Instruments and Techniques
local.identifier.ariespublicationa383154xPUB1160
local.publisher.urlhttp://pubs.acs.org.virtual.anu.edu.au/
local.type.statusPublished version
local.contributor.affiliationFogden, Andrew, Applied Mathematics School, Research School of Physics & Engineering, The Australian National University
local.contributor.affiliationDeniz, Vivianne, Applied Mathematics School, Research School of Physics & Engineering, The Australian National University
local.identifier.essn1520-5029
local.bibliographicCitation.issue2
local.bibliographicCitation.startpage666
local.bibliographicCitation.lastpage677
local.identifier.doi10.1021/ef502474a
dc.date.updated2015-12-10T10:09:08Z
local.identifier.scopusID2-s2.0-84923272254
CollectionsANU Research Publications

Download

There are no files associated with this item.


Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.

Updated:  19 May 2020/ Responsible Officer:  University Librarian/ Page Contact:  Library Systems & Web Coordinator