Application of Mass Spectrometry to Petroleum Exploration

Abstract

Compounds significant to the petroleum chemist concerned with petroleum exploration are those hydrocarbons possessing biological marker characteristics, that is, possessing intact steroid, terpenoid, and isoprenoid skeletons. These hydrocarbons are so closely related to the compounds occurring in the living organism from which petroleum was formed that they are capable of yielding very specific information regarding source, maturation, migration, and biodegradation of petroleum. Examples how source shales can be related to petroleum reservoirs using computerized gas chromatography/mass spectrometry, (GC/MS) are shown. The terpane GC/MS multiple array processor (MAP) approach can be used to differentiate source shales of different degrees of maturity and, thus, to determine source rock quality. Heavily biodegraded oils can be characterized and correlated by GC/MS fragmentograms of steranes and terpanes. Ratios of specific biomarkers obtained by quantitation from GC/MS data are used to differentiate oils of different degrees of migration. Examples from the exploration arena worldwide are given to illustrate these applications.

Study on the geochemical correlation of crude oils of Palaeocene and Jurassic ages from the Potowar Indus Basin in northern Pakistan

“…6 (m/z 217) which shows the sterane fragmentogram for three crude oils of the Upper Indus Basin of Pakistan. Similar sterane distributions have been found in Oman crude oils (Grantham 1986), the Dontrien shale, France (Ensminger et al, 1978), in crude oils from the McKittrick Field, California (Seifert and Moldowan, 1978), in Cretaceous shales and Permotriassic crude oil (Seifert and Moldowan, 1979b), in crudes from the German Molasse Basin (Hufnagel et al, 1980), in sediments from the Paris Basin (Mackenzie et al, 1981), in crude oils from the Williston Basin, Montana (Warburton and Zumberge, 1983), in the pyrolyzates of solid bitumens (Curiale et al, 1983), in bitumen from the Coal Port Tar Tunnel (Didyk et al, 1983), in crude oils and sediments from the Barrow sub-basin of Western Australia (Volkman et al, 1983), in a crude oils from the North Slope of Alaska (Mackenzie et al, 1983), crude oils from the Aquitane Basin (Connan et al, 1980), in crude oils and source rock extracts from a carbonate basin (Connan, 1980), in a refinery crude oil (Goodwin et al, 1983), in oil seeps from Tonga (Sandstrom and Philp, 1984), in extracts of bituminous chalks from Israel (Rullkotter et al, 1984) and in crude oils from the San Jorges Basin of Argentina (Philp, 1983). This type of distribution is by far most common.…”

Source Rock Potential and Depositional Environment of Upper Permian Oil Shales of the Lucaogou Formation in the Southeastern Junggar Basin, Northwest China

“…Concentrations of gammacerane are not significant in the oil shales of the studied sections, indicating brackish water depositional conditions. The 22S/(22S + 22R) ratio for C 31 homohopane increases with thermal maturity (0-0.6) and reaches the equilibrium value at 0.58-0.62 [53]. After reaching equilibrium at the early oil-generative stage, no further maturity information is available because the 22S/(22S + 22R) ratio remains constant [49,54].…”

Distribution and Isomerization of Terpanes in Pyrolyzates of Lignite at High Pressures and Temperatures

“…Pentacyclic terpanes record information concerning organic matter type, maturity level, source-rock lithology, and migration of hydrocarbons (Seifert et al, 1980;Blanc and Connan, 1992). The 18α(H)-22,29,30-trisnorhopane (Ts) and 17α(H)-22,29,30-trisnorhopane (Tm), two C 27 pentacyclic tristerpanes, are often analysed to assess the maturity level of a source rock (Rullkotter and Marzi, 1988;Peters and Moldowan, 1993).…”

“…Seifert and Moldowan, 1980;Peters and Moldowan, 1993;Lockhart et al, 2008;Duan et al, 2008). As the biologically produced 22R homohopanes can gradually be transformed into a mixture of 22R and 22S αβ-diastereomers, the 22S/(22S+22R) ratio of C 31 αβ-homohopanes or other homologues (C 32 , etc.)…”