Solubility of petroleum in oil-field waters as a function of the oxidation state of the system

Abstract

Research Article| September 01, 1994 Solubility of petroleum in oil-field waters as a function of the oxidation state of the system Vitalii A. Pokrovskii; Vitalii A. Pokrovskii 1Department of Geology and Geophysics, University of California, Berkeley, California 94720-4767 Search for other works by this author on: GSW Google Scholar Harold C. Helgeson Harold C. Helgeson 1Department of Geology and Geophysics, University of California, Berkeley, California 94720-4767 Search for other works by this author on: GSW Google Scholar Geology (1994) 22 (9): 851–854. https://doi.org/10.1130/0091-7613(1994)022<0851:SOPIOF>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Vitalii A. Pokrovskii, Harold C. Helgeson; Solubility of petroleum in oil-field waters as a function of the oxidation state of the system. Geology 1994;; 22 (9): 851–854. doi: https://doi.org/10.1130/0091-7613(1994)022<0851:SOPIOF>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Aqueous solubilities of liquid nonane (C9H20 [liq]) with activities ranging from 1.0 in pure nonane to 0.1 and 0.01 in crude oil have been calculated at ∼120 °C and 400 bar as a function of oxygen fugacity (fO2(g), where g stands for gas) in a generic oil-field water containing representative concentrations of NaCl, CaCl2, MgCl2, and FeCl2 in equilibrium with minerals in the system CaO-MgO-FeO-CO2-O2-H2O. The calculations indicate that in the presence of calcite, the oxidative solubilities resulting from the formation of aqueous CO2, n-carboxylic acids, and other oxidized organic aqueous species from n-alkanes in crude oil are several orders of magnitude greater than their stoichiometric counterparts. For example, the oxidative solubility in the aqueous phase of nonane with an activity of 0.1 in crude oil coexisting with calcite at the oil-water interface increases dramatically with increasing log fO2,( g) at ∼120 °C and 400 bar from a stoichiometric solubility of ∼0.26 ppm to an oxidative solubility of ∼320 ppm at log fo2 (g)= -56, which is typical of the fugacity of oxygen in hydrocarbon reservoirs at ∼120 °C and 400 bar. Because oil-field waters are generally acidic, production of carbonic acid by the oxidative dissolution of crude oil in hydrocarbon reservoirs favors generation of secondary porosity at the oil-water interface, which may be mediated by hyperthermobarophilic microbes. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.