Formation characteristics and resource potential of Jurassic tight oil in Sichuan Basin

Li, Denghua; Li, Jianzhong; Zhang, Bin; Yang, Jiajing; Wang, Shaoyong

doi:10.1016/j.ptlrs.2017.05.001

Cited by 21 publications

(15 citation statements)

References 11 publications

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“…A set of gray siltstone, silty shale, black graygray black shale, and fine gray siltstone were found in the Lianggaoshan Formation. From the upper Liang Member I to the lower Liang Member II (Li et al, 2010;Li et al, 2017;Wang et al, 2018;Qing et al, 2019;Li X. et al, 2021), these sections were mainly deposited by gray-black shale deposits due to their favorable conditions for developing organic-rich shales. During the sedimentary period, the Lianggaoshan Formation went through a complete lake transgression and regression cycle.…”

Section: Sedimentary and Stratum Characteristicsmentioning

confidence: 99%

Quantitative Characterization for Pore Connectivity, Pore Wettability, and Shale Oil Mobility of Terrestrial Shale With Different Lithofacies—A Case Study of the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin of the Upper Yangtze Region in Southern China

et al. 2022

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Some major hydrocarbon-bearing basins are rich in shale with terrestrial facies in China, which may provide abundant terrestrial shale oil and gas resources. This work studied the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin of the upper Yangtze Region. Core samples were chosen for the total organic carbon content and mineral composition analyses to classify shale lithofacies. Afterward, pore connectivity, pore wettability, and shale oil mobility with different lithofacies were characterized by spontaneous imbibition, nuclear resonance, and centrifugation. Conclusions are as follows: the pore connectivity of organic-rich clay shale was mostly between moderate to good with oil-prone wettability and high mobile oil saturation. The organic-rich mixed shale has moderate to good pore connectivity, water-prone wettability, and the highest mobile oil saturation. Organic matter–bearing clay shale has bad to moderate pore connectivity. Meanwhile, its pore wettability covers oil wetting, mixed wetting, oil-prone wetting, and water-prone wetting. Its mobile oil saturation was moderate. Regarding organic matter–bearing mixed shale, the pore connectivity was bad to moderate with mixed-wetting pore wettability and moderate mobile oil saturation.

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Section: Sedimentary and Stratum Characteristicsmentioning

confidence: 99%

Quantitative Characterization for Pore Connectivity, Pore Wettability, and Shale Oil Mobility of Terrestrial Shale With Different Lithofacies—A Case Study of the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin of the Upper Yangtze Region in Southern China

et al. 2022

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“…The main source rocks in the centre of the basin consist of lacustrine shales in the Lower Jurassic Da'anzhai Member of the Ziliujing Formation and the directly overlying Lianggaoshan Formation. The Da'anzhai Member shales contain Type II kerogen, and have TOC and vitrinite reflectance (VR) values of 1.0-1.8% and 0.9-1.6 R o % respectively Li et al, 2017). The TOC and VR values of the mudstones in the Lianggaoshan Formation vary from 1.0 to 1.6% and 0.8 to 1.3 R o %.…”

Section: Geologic Settingmentioning

confidence: 99%

“…By contrast, the reservoirs in the Lianggaoshan Formation and the First Member of the Shaximiao Formation are dominated by fine-grained sandstones and siltstones with cumulative thicknesses ranging from 10 to 30m, and 50 to 200 m, respectively. The sandstone reservoir rocks in both the Lianggaoshan Formation and the First Member of the Shaximiao Formation are characterised by low average porosities and air permeabilities (< 4.2% and 0.49 mD respectively: Chen et al, 2014;Li et al, 2017).…”

Section: Geologic Settingmentioning

confidence: 99%

“…The tight Lianggaoshan Formation reservoir is likewise self-sourced by similar OM-rich dark mudstones (Chen et al, 2014;Chen et al, 2015;. In addition, the shale source rocks in these two units have generated the light oils which are reservoired in the Middle Jurassic First Member of the Shaximiao Formation (Li et al, 2017;Lu et al, 2021). Recent exploration efforts in the Qiulin and Bajiaochang areas near to the Gongshanmiao and Jinhua oilfields in the centre of the Sichuan Basin have led to the discovery of tight oils in the overlying Second Member of this formation (J 2 s 2 ) (Huang et al, 2021), although the origin of this oil remains unclear.…”

Section: Introductionmentioning

confidence: 99%

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Composition of Light Hydrocarbons in Jurassic Tight Oils in the Central Sichuan Basin, China: Origin and Source Rock Correlation

Wei³

et al. 2022

Journal of Petroleum Geology

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Crude oil reserves in tight Middle and Lower Jurassic reservoirs are of increasing exploration interest in the central Sichuan Basin, SW China. However, the origin of these “tight oils” is poorly understood. In this study, sixteen samples of light oils/condensates from tight Middle and Lower Jurassic reservoir rocks were analysed using gas chromatography (GC) and isotope ratio mass spectrometry to investigate the oils’ origin and to classify them into genetic families. The tight oils can be divided into two families. Family I oils occur in the Gongshanmiao oilfield where reservoir units comprise the Da'anzhai Member of the Lower Jurassic Ziliujing Formation, the Lower Jurassic Lianggaoshan Formation, and the First Member of the Middle Jurassic Shaximiao Formation. Family I oils are characterized by relatively low values of the methylcyclohexane (MCH) and cyclohexane (CH) indexes, low values of Mango's parameter K2 for light hydrocarbon composition, and relatively negative δ13C values ranging from ‐30.8‰ to ‐28.9‰. Family I oils are inferred to be self‐sourced by lacustrine shales in the Da'anzhai Member and the Lianggaoshan Formation in the study area, both of which are rich in sapropelic organic matter. These source rocks also charged reservoirs in the First Member of the Shaximiao Formation. By contrast, the newly discovered Family II oils, which occur at the Jinhua oilfield and the as‐yet undeveloped Qiulin and Bajiaochang structures, are reservoired in the Second Member of Shaximiao Formation. Family II oils have higher values of the MCH index, CH index and Mango's K2 parameter, and δ13C values varying from ‐27.5‰ to ‐25.4‰. These oils have similar light hydrocarbon compositions and δ13C values to oils derived from source rocks in the Upper Triassic Xujiahe Formation which contain dominantly humic organic matter. Family II oils are therefore inferred to be derived from the coaly mudstones in the Xujiahe Formation.The different compositions of the tight oils in the First and Second Members of the Shaximiao Formation appear to be controlled by the distribution and thickness of source rocks in the study area. Thus, the Gongshanmiao oilfield where Family I oils occur in the First Member is close to the depocentre of source rocks in the Da'anzhai Member and Lianggaoshan Formation. These source rocks are inferred to have charged the First Member reservoirs which may also be present in nearby oil‐ and gas‐bearing structures such as Nanchong and Yingshan. By contrast, Family II oils occur in tight reservoirs in the Second Member in areas with thick successions of Upper Triassic Xujiahe Formation mudstone source rocks, such as the Jinhua oilfield. In areas where both source rocks are present such as the Zhongtaishan and Lianchi oilfields, Shaximiao Formation reservoirs appear to contain both Family I and Family II oils.

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“…More than 90% of the world's recoverable hydrocarbon reserves are produced from six sets of source rocks, including Jurassic source rocks which account for about 25% of the total source rocks in the whole geological period, and Jurassic tight oil reserves account for 31.0% of the total tight oil resources (Klemmeetal, 1991; Ma et al., 2014; Wang 2016; Zou et al., 2015). In China, the tight oil resources of Jurassic system can reach 16.10 × 10 8 t, and economical production from the Middle–Lower Jurassic Formation in the Sichuan Basin has been documented (Li et al., 2017; Zheng et al., 2019). Moreover, the Jurassic source rocks in Qaidam Basin, Yabrai basin (The estimated resource of tight oil is 0.92 × 10 8 t) are of high quality and have potential for tight oil exploration (Fu et al., 2013; Gao et al., 2017; Liu et al., 2008).…”

Section: Introductionmentioning

confidence: 99%

Hydrocarbon generation and expulsion of Middle Jurassic lacustrine source rocks in the Turpan–Hami Basin, NW China: Implications for tight oil accumulation

Yuan

Huang

et al. 2020

Energy Exploration & Exploitation

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In recent years, new oil reservoirs have been discovered in the middle Jurassic tight mixed rocks of the Turpan–Hami Basin. However, the generation potential of the J2q2 source rocks remains poorly understood. Petrographic, petrological, and geochemical analyses were carried out to assess the quality of the J2q2 source and reservoir rocks. The hydrocarbon generation potential method was utilized to evaluate the hydrocarbon generation and expulsion potentials. The results indicated that the rocks can be classified as high-quality source rocks with a relative lower degree of maturity. The hydrocarbon bearing zones are classified as tight reservoirs (average porosity of 5.90% and permeability of 0.18 mD) with an average pore throat radius >150 nm, which is higher than the cut-off pore-throat radius. The source rocks start to expel hydrocarbons when Ro% is 0.56%. Bulk hydrocarbon generation and expulsion intensities in the center of the study area were calculated with the values of 900 × 104 t/km2 and 400 × 104 t/km2, while the weights of these hydrocarbons were 48.8 × 108 t and 27.3 × 108 t, respectively. The tight oil reservoir-forming conditions are superior, and the hydrocarbon generation and expulsion intensities are more remarkable in controlling the tight oil distribution. This study provides an important example for the Jurassic source rocks in Western China, and indicates that middle Jurassic lacustrine source rocks deserve attention in future exploration.

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Formation characteristics and resource potential of Jurassic tight oil in Sichuan Basin

Cited by 21 publications

References 11 publications

Quantitative Characterization for Pore Connectivity, Pore Wettability, and Shale Oil Mobility of Terrestrial Shale With Different Lithofacies—A Case Study of the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin of the Upper Yangtze Region in Southern China

Quantitative Characterization for Pore Connectivity, Pore Wettability, and Shale Oil Mobility of Terrestrial Shale With Different Lithofacies—A Case Study of the Jurassic Lianggaoshan Formation in the Southeast Sichuan Basin of the Upper Yangtze Region in Southern China

Composition of Light Hydrocarbons in Jurassic Tight Oils in the Central Sichuan Basin, China: Origin and Source Rock Correlation

Hydrocarbon generation and expulsion of Middle Jurassic lacustrine source rocks in the Turpan–Hami Basin, NW China: Implications for tight oil accumulation

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