Forward Analysis of Origin of Mixed Oil and Gas and Relative Contribution of Source Rocks in Tarim Basin: A Case Study from Tazhong Area

2016 ◽  
Author(s):  
Qianwen Li ◽  
Xiongqi Pang ◽  
Zhipeng Huo ◽  
Junwen Peng ◽  
Junqing Chen ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Oil And Gas ◽  
Source Rocks ◽  
Relative Contribution ◽  
Forward Analysis ◽  
Tazhong Area ◽  
Mixed Oil

scholarly journals Fluid geochemistry of the Jurassic Ahe Formation and implications for reservoir formation in the Dibei area, Tarim Basin, northwest China

2018 ◽  
Vol 36 (4) ◽  
pp. 801-819 ◽  
Author(s):  
Shuangfeng Zhao ◽  
Wen Chen ◽  
Zhenhong Wang ◽  
Ting Li ◽  
Hongxing Wei ◽  
...  
Keyword(s):  
Natural Gas ◽  
Tarim Basin ◽  
Oil And Gas ◽  
Northwest China ◽  
Source Rocks ◽  
Coal Measure ◽  
Hydrocarbon Generation ◽  
Gas Reservoirs ◽  
Isotopic Analyses ◽  
Jurassic Coal

The condensate gas reservoirs of the Jurassic Ahe Formation in the Dibei area of the Tarim Basin, northwest China are typical tight sandstone gas reservoirs and contain abundant resources. However, the hydrocarbon sources and reservoir accumulation mechanism remain debated. Here the distribution and geochemistry of fluids in the Ahe gas reservoirs are used to investigate the formation of the hydrocarbon reservoirs, including the history of hydrocarbon generation, trap development, and reservoir evolution. Carbon isotopic analyses show that the oil and natural gas of the Ahe Formation originated from different sources. The natural gas was derived from Jurassic coal measure source rocks, whereas the oil has mixed sources of Lower Triassic lacustrine source rocks and minor amounts of coal-derived oil from Jurassic coal measure source rocks. The geochemistry of light hydrocarbon components and n-alkanes shows that the early accumulated oil was later altered by infilling gas due to gas washing. Consequently, n-alkanes in the oil are scarce, whereas naphthenic and aromatic hydrocarbons with the same carbon numbers are relatively abundant. The fluids in the Ahe Formation gas reservoirs have an unusual distribution, where oil is distributed above gas and water is locally produced from the middle of some gas reservoirs. The geochemical characteristics of the fluids show that this anomalous distribution was closely related to the dynamic accumulation of oil and gas. The period of reservoir densification occurred between the two stages of oil and gas accumulation, which led to the early accumulated oil and part of the residual formation water being trapped in the tight reservoir. After later gas filling into the reservoir, the fluids could not undergo gravity differentiation, which accounts for the anomalous distribution of fluids in the Ahe Formation.

scholarly journals Possible new method to discriminate effective source rocks in petroliferous basins: A case study in the Tazhong area, Tarim Basin

2019 ◽  
Vol 38 (2) ◽  
pp. 417-433
Author(s):  
Bo Pang ◽  
Junqing Chen ◽  
Xiongqi Pang ◽  
Tuo Liu ◽  
Haijun Yang ◽  
...  
Keyword(s):  
Source Rocks ◽  
New Method ◽  
Burial Depth ◽  
Hydrocarbon Generation ◽  
Upper Ordovician ◽  
Hydrocarbon Generation Potential ◽  
Potential Index ◽  
Tazhong Area ◽  
Effective Source

Sediments with organic matter content (total organic carbon) TOC ≤ 0.5% which can act as effective source rocks are critical and challenging in the field of petroleum geology. A new method is proposed through a case study to identify and evaluate the effective source rocks, which is applied to study the changing characteristic of hydrocarbon-generation potential index with depth. The burial depth corresponding to the beginning of hydrocarbon-generation potential index reduction represents the hydrocarbon expulsion threshold in source rocks. Then, new identification standards are established for discrimination of effective source rocks of Middle–Upper Ordovician in Tarim Basin. The critical value of TOC for effective source rocks change with their burial depth: the TOC > 0.5% with source rock depth > 4000 m, TOC > 0.4% with depth >4500 m, TOC > 0.3% with depth > 5000 m, TOC > 0.2% with depth >5500 m. Based on the new criteria, effective source rocks in the Middle–Upper Ordovician are identified and their total potential hydrocarbon resources is evaluated, reaches 0.68 × 109 t in the Tazhong area, which is 65.4% higher than that of previous studies and consistent with the exploration result. Thus, this new method is of significance to resource evaluation and can be applied in the carbonate source rocks and mudstone source rocks with high degree of exploration.

Application of sulfur and carbon isotopes to oil–source rock correlation: A case study from the Tazhong area, Tarim Basin, China

2015 ◽  
Vol 83-84 ◽  
pp. 140-152 ◽  
Author(s):  
Chunfang Cai ◽  
Chunming Zhang ◽  
Richard H. Worden ◽  
Tiankai Wang ◽  
Hongxia Li ◽  
...  
Keyword(s):  
Carbon Isotopes ◽  
Source Rock ◽  
Tarim Basin ◽  
Tazhong Area ◽  
Oil Source

Hydrocarbon migration along fault intersection zone - A case study on Ordovician carbonate reservoirs in Tazhong area, Tarim Basin, NW China

2016 ◽  
Vol 52 (5) ◽  
pp. 832-850
Author(s):  
Yangyang Wang ◽  
Jianfa Chen ◽  
Xiongqi Pang ◽  
Gui Wang ◽  
Tao Hu ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Carbonate Reservoirs ◽  
Hydrocarbon Migration ◽  
Nw China ◽  
Tazhong Area
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