Origin and quantitative source assessment of deep oils in the Tazhong Uplift, Tarim Basin

Characteristics and Main Controlling Factors of Source Rock in Cambrian Yuertus Formation in Aksu Area, Tarim Basin

“…Currently, most of scholars believe that marine oil and gas in Tarim Basin are mainly derived from the Cambrian-Ordovician source rocks [4][5]. In recent years, with the breakthrough in Cambrian system from deep wells of ZS1 and ZS5, marking the first success of commercial hydrocarbon flow in dolomite formation under salt in Tarim Basin, it confirms the Cambrian dolomite formation under salt have petroleum geological conditions of largescale accumulation, which has opened a new field for deep exploration in Tarim Basin [6].…”

Unmixing of mixed oil using chemometrics

“…In basins with multiple source rocks and episodic charge histories, this problem becomes more difficult, especially when petroleum from several different source rocks has mixed in the same reservoir (Arouri and McKirdy, 2005). Previous attempts to estimate the relative contributions of different source rocks to oil pools with multiple sources have employed the following methods: (1) carbon isotopic compositions, including carbon isotopic compositions of oil and source rock extracts, and compound-specific isotope ratios (averaged d 13 C value of n-C 11 -n-C 25 ) of oil (Peters et al, 1989;Li et al, 2015); (2) age-and source-specific biomarkers (Dzou et al, 1999;Peters et al, 1999); (3) artificial mixing of typical end-member oils (Arouri and McKirdy, 2005); (4) mathematical calculations based on wholeoil carbon isotopic compositions, and concentrations of selected alkane biomarkers and/or aromatic hydrocarbons (Chen et al, 2003b(Chen et al, , 2007; and (5) alternating least squares (ALS) analysis using concentration data for biomarkers (Peters et al, 2008b;Tao et al, 2010). Based on the occurrence of biomarkers such as oleanane, b-carotane, 25-norhopanes, 24-n-propylcholestanes, and 23-or 27-nordiacholestanes, Peters et al (1999) proposed that the crude oil in a sandstone clast from Brora, Scotland is a mixture of oil derived from a Devonian lacustrine source rock and a Middle Jurassic coaly marine shale.…”

“…They used a massbalance approach based on concentrations of individual aromatic hydrocarbons. Li et al (2015) identified and calculated the relative http://dx.doi.org/10.1016/j.orggeochem.2015.11.006 0146-6380/Ó 2015 Elsevier Ltd. All rights reserved.…”

De-convoluting crude oil mixtures from Palaeozoic reservoirs in the Tabei Uplift, Tarim Basin, China

“…Second, such basins contain a range of petroleum types, including dry gas, wet gas, condensate, light oil, heavy oil and solid bitumen. Multiple oil generation and filling stages and a number of post-accumulation processes, e.g., mixing, biodegradation, fractionation, have been proposed to explain the diverse oil occurrence and formation (Zhang, 2000;Wang et al, 2008;Pan and Liu, 2009;Jia et al, 2010Jia et al, , 2013Zhang et al, 2011Zhang et al, , 2014Zhang et al, , 2015Li et al, 2012Li et al, , 2015Tian et al 2012a,b;Zhu et al, 2012Zhu et al, , 2013Zhu et al, , 2014b.…”

“…A similar conclusion was drawn by Hanson et al (2000). An increasing number of studies suggest that marine oils from Palaeozoic reservoirs are actually mixtures generated from two marine source rocks (Li et al, 2010(Li et al, , 2015Yu et al, 2011;Zhu et al, 2012Zhu et al, , 2013Zhu et al, ,2014bTian et al, 2012b ;Tian, 2013 contribute to the oils and when and how the mixing process occurred. Li et al (2010Li et al ( , 2015 showed that the majority of oils in the Tazhong Uplift are mixtures derived from two source rocks and calculated the percentage contributions of the CambrianLower Ordovician ranging from 19% to 100% by combining carbon isotopic compositions and concentrations of n-alkanes (averaged d…”