Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-14T06:56:40.266Z Has data issue: false hasContentIssue false

Non-hydrocarbons of significance in petroleum exploration: volatile fatty acids and non-hydrocarbon gases

Published online by Cambridge University Press:  05 July 2018

G. P. Cooles
Affiliation:
British Petroleum Company plc, BP Research Centre, Chertsey Road, Sunbury-on-Thames, Middlessex TW16 7LN
A. S. Mackenzie
Affiliation:
British Petroleum Company plc, BP Research Centre, Chertsey Road, Sunbury-on-Thames, Middlessex TW16 7LN
R. J. Parkes
Affiliation:
Scottish Marine Biological Association, Dustaffnage Marine Research Laboratory, PO Box 3, Oban, Argyll PA34 4AD

Abstract

Non-hydrocarbon gas species (CO2, N2, H2) are locally important in exploration for gas, and there is a growing body of evidence that acid water originating in shales materially affects the diagenesis of nearby sandstones. These gases have been studied by analysing the products of closed-vessel hydrous pyrolysis of known petroleum source rocks, and comparing the results with field observations. Alteration of petroleum source rocks at temperatures >250°C yields a significant amount of non-hydrocarbon components. Ethanoate and higher acid anions are liberated in substantial quantities; the yield appears to be related to the oxygen content of the sedimentary organic matter present.

The non-hydrocarbon gases CO2, H2 and N2 are frequently the dominant gaseous products from hydrous pyrolysis: in the natural environment the same rock sequences at a higher maturity preferentially generate hydrocarbon gases—mainly methane. This discrepancy may be attributed to reaction and phase thermodynamic effects between laboratory and natural systems, behaviour that has important implications in the prediction of gas generation and composition in nature by source rock pyrolysis in the laboratory.

Type
Mineralogy and petroleum genesis
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

Present address: BP Petroleum Development (Norway) Ltd, Forusbeen 35, PO Box 197, 44033 Forus, Norway.

References

British Petroleum (1977) Our Industry Petroleum (5th ed.) Jarrold and Sons Ltd, Norwich.Google Scholar
Carothers, W.W. and Kharaka, Y.K. (1978) Aliphatic anions in oil-field waters-—Implications for origin of natural gas. Am. Assoc. Pet. Geol. Bull. 62, 2441-53.Google Scholar
Cooles, G.P., Mackenzie, A.S. and Quigley, T.M. (1986) Calculation of masses of petroleum generated and expelled from source rocks. In Advances in Organic Geochemistry 1985 (Leythaeuser, D. and Rullkotter, J., eds) Pergamon, Oxford 1, 235-45.Google Scholar
Harwood, R.J. (1977) Oil and gas generation by laboratory pyrolysis of kerogen. Am. Assoc. Pet. Geol. Bull. 61, 2081-102.Google Scholar
Henderson, M.H. and Steedman, T.A. (1982) Analysis of C2-C6 monocarboxylic acids in aqueous solution using gas chromatography. J. Chromatog. 244, 337.Google Scholar
Holloway, J.R. (1984) Graphite-CH4-H20-CO2 equilibria at low-grade metamorphic conditions. Geolog. 12, 455-8.Google Scholar
Hungate, R.E. (1966) The rumen and its microbes. Academic Press, New York and London.Google Scholar
Hunt, J.M. (1979) Petroleum geochemistry and geology. W. H. Freeman and Co., San Francisco.Google Scholar
Jeris, J.S. and McCarty, P.L. (1965) The biochemistry of methane formation using 14C tracers. J. Wat. Pollut. Control Fed. 37, 178-92.Google Scholar
Jorgensen, B.B. (1982) Mineralisation of organic matter in the sea bed-—the role of sulphate-reduction. Natur. 296, 643-5.Google Scholar
Lewan, M.D., Winters, J.C. and McDonald, J.H. (1979) Generation of oil-like pyrolysates from organic rich shales. Scienc. 203, 897-9.Google Scholar
Lovley, D.R. and Klug, M.J. (1982) Intermediary metabolism of organic matter in the sediments of a eutrophiclake. Appl. envirl Microbiol. 43, 552-60.Google Scholar
Lundegard, P.D., Land, L.S. and Galloway, W, E, (1984) Problem of secondary porosity: Frio Formation (Oligocene), Texas Gulf Coast. Geology 12, 399-402.Google Scholar
McAuliffe, C. (1963) Solubility in water of CrC9 hydrocarbons. Natur. 200, 1092-3.Google Scholar
Merck and Co., Inc. (1976) The Merck Index and Encyclopedia of Chemicals and Drugs (9th ed.) Rahway, NJ, USA, ISBN 911910-26-3.Google Scholar
Parkes, R.J. and Taylor, J. (1983) Analysis of volatile fatty acids by ion exclusion chromatography, with special reference to marine pore water. Marine Biol. 77, 113-8.Google Scholar
Sansone, F.J. and Martens, C.S. (1981) Determination of volatile fatty acid turnover rates in organic-rich marine sediments. Marine Chem. 10, 233-47.Google Scholar
Saxby, J.D., Bennett, A.J. R., Corcoran, J.F., Lambert, D.E. and Riley, K.W. (1985) Petroleum generation: Simulation over six years of hydrocarbon formation from torbanite and brown coal in a subsiding basin. Organic Geochem. 9, 69-81..Google Scholar
Sorensen, J., Christensen, D. and Jorgensen, B.B. (1981) Volatile fatty acids and hydrogen as substrates for sulphate-reducing bacteria in anaerobic marine sediment. Appl. envirl Microbiol. 42, 5-11.Google Scholar
Surdam, R.C., Crossley, L.J., Hagen, E.S. and Heasler, H. (1984) Time-temperature reconstructions of diagenetic systems. 97th Annual meeting, Geol. Soc. Am. (Abstr. no. 51690).Google Scholar
van de Meent, D., Los, A., Leeuw, J.W. and Schenck, P.A. (1983) Size fractionation and analytical pyrolysis of suspended particles from the River Rhine Delta. In Advances in Organic Geochemistry 1981 (Bjoroy etal., eds) John Wiley, 336-49.Google Scholar