The effects of reservoir brine compositions on interfacial tension and reservoir wettability under reservoir conditions*
Abdolvahab Honari A , Keyu Liu B , Brendan Graham C and Mohammad Bahar DA The University of Western Australia 35 Stirling Hwy, Crawley, WA 6009. Email: honara01@student.uwa.edu.au
B CSIRO Earth Science and Resource Engineering P.O. Box 1130, Bentley, WA 6102. Email: Keyu.Liu@csiro.au
C The University of Western Australia 35 Stirling Hwy, Crawley, WA 6009. Email: brendan.graham@uwa.edu.au
D CSIRO Earth Science and Resource Engineering P.O. Box 1130, Bentley, WA 6102. Email: Mohammad.bahar@gmail.com
The APPEA Journal 50(2) 735-735 https://doi.org/10.1071/AJ09099
Published: 2010
Abstract
The average primary oil recovery worldwide is around 35% of the original oil in place (OOIP). Various enhanced oil recovery (EOR) approaches are generally required to recover the remaining OOIP. Apart from the reservoir properties, the capillary pressure that governs fluid distribution and displacement behaviour in the reservoir is also affected by the interfacial tension and wettability. Both IFT and wettability are considered to be key effective factors that affect EOR.
This study investigated the effect of reservoir brine compositions on the interfacial tension (IFT) between synthetic formation brines and an Australian crude oil with pressures and temperatures up to 4,000 psi and 140 °F, respectively. A series of measurements on the density, viscosity and IFT have been conducted.
The brines, with total dissolved solids ranging from 3,820 to 38,200 ppm, consist of a diverse range of ions including sodium, lithium, magnesium, calcium, bromide, chloride, sulfate, bicarbonate and carbonate.
The experimental results indicate that with all the synthetic brines investigated, the IFT declines with increasing temperature and pressure. Furthermore, it was observed that the IFT reduction with temperature was dependent on the pH values of the brine. Bicarbonate, carbonate, sulfate, and magnesium ions significantly decreased the IFT by up to 40% through either lowering the free surface energy or increasing the surface area. Coreflooding experiments using low salinity water have yielded an incremental EOR of 5.4% OOIP, suggesting that wettability alteration caused by the change of ion balance in the residual water may be responsible for the observed EOR.
Keywords: interfacial tension (IFT), brine composition, wettability, oil recovery
Abdolvahab Honari is a postgraduate student at the University of Western Australia, with a major in oil and gas engineering. He also has a BSc in mechanical engineering from Amirkabir University of Technology, Iran. Member: SPE and PESA. |
Dr Keyu Liu is a principal research scientist and research team leader of the Fluid History Analysis Team at CSIRO.’His principal research areas are: clastic sedimentology; hydrocarbon migration and charge history of petroleum reservoirs; and, laboratory experiments on enhanced oil recovery. Keyu has a BSc from China Ocean University, an MSc from the University of Sydney, and a PhD from the Australian National University. Member: AAPG, SPE, AGU, IAS and PESA. |
Dr Brendan Graham is currently employed as an assistant professor in the Centre for Energy at UWA.’He’obtained both his undergraduate degree and PhD from UWA, with a focus on analytical chemistry. After completing his studies Brendan worked for Agilent Technologies as their southeast Asian customer trainer before moving into the oil and gas industry where, amongst other projects, he has consulted for major’oil companies on their emulsion issues in West Africa. In his current academic position Brendan’s research interests lie primarily in flow assurance and include the study of the influence of oil resins in asphaltene stability as well as hydrate formation/stability and heavy oil transport issues. |
Mohammad Bahar was employed as a reservoir engineer with CSIRO Petroleum from 2006 to 2009 working on the laboratory coreflooding experiments for Microbially enhanced oil recovery project. He did his PhD in petroleum engineering at Curtin University of Technology from 2002 to 2006. Prior to that, Mohammad worked with the research Institute of the Iranian National Company more than 10’years as a research engineer. Member: SPE. |
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