Paleozoic oil–source rock correlations in the Tarim basin, NW China

Identification of the Kukersite-type source rocks in the Ordovician Stratigraphy from the Tarim Basin, NW China

“…The crude oil contributed by G. prisca usually has distinctive molecular geochemical fingerprint. In another word, there is odd-carbon number predominance such as n-C 15 , n-C 17 and n-C 19 in N-alkanes with low carbon numbers; meanwhile the relevant content of N-alkanes with high carbon numbers is very less [1][2][3][4][5][6][7][8][9][10][11][12][13]. According to the statistics, Kukersite-type source rocks are the primary contributor of petroleum resources of the Lower Paleozoic marine petroleum field that is discovered in north American platform, including the G. prisca-enriched and G. prisca-diluted types [11].…”

“…It has become the biggest palaeozoic marine oil field (Tahe-Lunnan 100 million ton oil field) as a result of large-scale explorations of 30 years in the Tarim Basin. Due to the importance of Ordovician marine source rocks in the global exploration of Paleozoic petroleum resources and the con-sideration of the actual results of the basin biomarker oilsource correlation of compounds, most geochemists believe that the Middle and Upper Ordovician source rocks are the major source rocks of marine crude oil in the Tarim Basin [14][15][16][17][18][19][20]. There are a great amount of geochemical evidences such as molecules and isotope that prove the fact that the Cambrian-Lower Ordovician source rocks had significant contributions to the Lower Paleozoic petroleum systems which have been found so far [21][22][23][24][25].…”

Isotopic compositions and biomarkers in crude oils from the Tarim Basin: Oil maturity and oil mixing

“…Biological markers indicative of the source rocks from oils in the Tarim Basin have been comprehensively investigated Zhang et al, 2000;Zhu et al, 2007;Pan and Liu, 2009;Li et al, 2010;Yu et al, 2011). In brief, oils derived from the Cambrian-Lower Ordovician strata commonly show relatively high abundances of gammacerane, C 28 regular steranes, dinosteranes and triaromatic dinosteranes.…”

“…The occurrence and formation of marine oils and reservoir bitumen in this basin attracted many geochemists' attention in the past decade due to the long, complex and deep burial geological history of oils Li et al, 2000Li et al, , 2010Zhang et al, 2000Zhang et al, , 2011Sun et al, 2003;Jia et al, 2008Jia et al, , 2010Cai et al, 2009;Pan and Liu, 2009;Yu et al, 2011Yu et al, , 2012. The two old marine oil source units identified in the basin are the Cambrian-Lower Ordovician and Middle-Upper Ordovician strata Zhang et al, 2000).…”

“…The occurrence and formation of marine oils and reservoir bitumen in this basin attracted many geochemists' attention in the past decade due to the long, complex and deep burial geological history of oils Li et al, 2000Li et al, , 2010Zhang et al, 2000Zhang et al, , 2011Sun et al, 2003;Jia et al, 2008Jia et al, , 2010Cai et al, 2009;Pan and Liu, 2009;Yu et al, 2011Yu et al, , 2012. The two old marine oil source units identified in the basin are the Cambrian-Lower Ordovician and Middle-Upper Ordovician strata Zhang et al, 2000). Multiple oil generation and filling stages have been proposed as the mechanism of diverse oil formation, e.g., normal, light, waxy and heavy oils occurring in the basin Gong et al, 2007;Wang et al, 2008;Pan and Liu, 2009;Jia et al, 2010;Li et al, 2010;Yu et al, 2011).…”