scholarly journals Geochemical Characteristics and Origins of the Crude Oil of Triassic Yanchang Formation in Southwestern Yishan Slope, Ordos Basin

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaoli Zhang ◽  
Jinxian He ◽  
Yande Zhao ◽  
Hongchen Wu ◽  
Zeqiang Ren
Keyword(s):  
Crude Oil ◽  
Oil And Gas ◽  
Saturated Hydrocarbon ◽  
Ordos Basin ◽  
Water Environment ◽  
Geochemical Characteristics ◽  
Source Rocks ◽  
Gas Chromatography Mass Spectrometry ◽  
Yanchang Formation ◽  
Parent Materials

Biomarker compounds that derived from early living organisms play an important role in oil and gas geochemistry and exploration since they can record the diagenetic evolution of the parent materials of crude oil and reflect the organic geochemical characteristics of crude oil and source rocks. To offer scientific basis for oil exploration and exploitation for study area, gas chromatography-mass spectrometry method is applied to study the biomarker compounds of crude oil in Southwestern Yishan Slope of Ordos Basin, through qualitatively and quantitatively analyzing separated materials. The crude oil of Yanchang Formation and the source rocks of Yan’an and Yanchang Formation were collected in order to systematically analyze the characteristics of the biomarker compounds in saturated hydrocarbon fractions and clarify the organic geochemical characteristics of crude oil. The distribution and composition of various types of hydrocarbon biomarker compounds in crude oil suggest that the parent materials of crude oil are composed of hydrobiont and terrigenous plants, and the crude oil is mature oil which is formed in the weak reducing fresh water environment. Oil source correlation results show that the crude oil of Yanchang Formation in Yishan Slope is sourced from the source rocks of Chang 7 subformation.

Geochemical characteristics and origin of Chang-9 crude oil of Triassic Yanchang Formation in Zhidan area, Ordos Basin, China

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Zhengyu Wu ◽  
Shijia Chen ◽  
Chengshan Li ◽  
Jian Yu ◽  
Yibo Chang ◽  
...  
Keyword(s):  
Crude Oil ◽  
Ordos Basin ◽  
Geochemical Characteristics ◽  
Yanchang Formation

GEOCHEMICAL CHARACTERISTICS AND SOURCE OF CHANG 8 CRUDE OIL IN THE EAST PART OF SHANBEI SLOPE, ORDOS BASIN, CHINA

2021 ◽  
pp. 1-31
Author(s):  
Zhenglu Xiao ◽  
Shijia Chen ◽  
Xiangdong Yin ◽  
Pan Wang ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Source Rock ◽  
Higher Plants ◽  
Saturated Hydrocarbon ◽  
Vitrinite Reflectance ◽  
Sedimentary Environment ◽  
Ordos Basin ◽  
Aquatic Organisms ◽  
Source Rocks ◽  
East Part

There are three sets of potential source rocks in the Yanchang Formation in the east part of the Shanbei Slope in the Ordos Basin. Based on the experimental results of total organic carbon, vitrinite reflectance, rock organic matter extraction, and saturated hydrocarbon chromatography (GC-MS), we have analyzed the geochemical and biomarker characteristics of the Chang 7, Chang 8, and Chang 9 source rocks, and the Chang 8 reservoir extracts and find that the Chang 7, Chang 8, and Chang 9 source rocks were deposited in the sedimentary environment of weak oxidation and weak reduction. Higher plants contribute more in the parent materials of the Chang 7 and Chang 9 source rocks, whereas lower aquatic organisms contribute more to the Chang 8 source rock. However, the source of the Chang 8 crude oil in the east part of Shanbei Slope does not match the chemical fingerprint of the Chang 8 source rock. To address this problem, we examined samples taken from the Zhidan oilfield, where our results show that the Chang 7, Chang 8, and Chang 9 source rocks all have hydrocarbon-supplying capacity. The relative abundance of regular steranes (C27, C28, C29) and hopane (17α(H), 21β(H)-hopane, 17β(H)-rearranged hopane, 18α(H)-22,29,30-trinorhopane) provides a means to assign the crude oil components to a given. Further analysis of the biomarkers of the three source rocks and those of the Chang 8 crude oil indicate that crude oil in the Chang 8 reservoir was not generated in situ; rather, it was supplied by the underlying Chang 9 source rock.

Source and reservoir characteristics of Upper Triassic lacustrine Chang 6 tight oil play in Zhangjiagou area, Ordos Basin, China

2021 ◽  
pp. 1-27
Author(s):  
Yan Cao ◽  
Hui Han ◽  
Shijia Chen ◽  
Rui Liu ◽  
Jingyue Zhang ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Ordos Basin ◽  
Micropore Volume ◽  
Source Rocks ◽  
Gas Chromatography Mass Spectrometry ◽  
Major Type ◽  
Tight Oil ◽  
Tight Sandstone ◽  
Yanchang Formation ◽  
Reservoir Characteristics

To explore the source and reservoir characteristics of Chang 6 tight oil in the Zhangjiagou area, we have extracted a suite of Chang 6 tight sandstones and the source rocks from the seventh to ninth members of the Upper Cretaceous Yanchang Formation in the Ordos Basin, China, respectively, using chloroform. We examined group components by fractionations of extracted organic matter. Using low-pressure gas adsorptions and gas chromatography-mass spectrometry, respectively, we analyzed the pore structure of the studied samples before and after extraction and the oil source of the separate saturated hydrocarbon components. The results indicate that the porosity of the Chang 6 tight sandstone is mainly distributed in the 8%–14% range, averaging 10.5%, the permeability of the studied reservoir is only approximately 0.16 × 10−3 μm2, and the pore-throat radius is mainly less than 2 μm. The major type of pores of the reservoir includes the residual intergranular pore, secondary intergranular dissolved pore, and intragranular dissolved pore. The micropore volume of the Chang 6 tight sandstone is in the range of 0.0071–0.0092 cm3/g, and the mesopore volume of the Chang 6 tight sandstone is in the range of 0.0237–0.0343 cm3/g. The micropore volume and micropore surface area significantly increased after chloroform extractions, and soluble hydrocarbons could be stored in micropores of the Chang 6 tight sandstone. The three sets of source rocks from the seventh to ninth members of the Upper Cretaceous Yanchang Formation are high quality by the evaluation of source rocks, and the Chang 7 has the highest value of source rocks, followed by Chang 9 and Chang 8. The pentacyclic triterpene characteristics (Ts-C30H-C30*) of Chang 6 crude oil are similar to those of Chang 7 source rock, and the tight oil of the Chang 6 member in the Zhangjiagou area originated from Chang 7 source rocks.

Geochemical characteristics of the source rocks in Mesozoic Yanchang formation, central Ordos Basin

2013 ◽  
Vol 24 (5) ◽  
pp. 804-814 ◽  
Author(s):  
Senhu Lin ◽  
Xuanjun Yuan ◽  
Shizhen Tao ◽  
Zhi Yang ◽  
Songtao Wu
Keyword(s):  
Ordos Basin ◽  
Geochemical Characteristics ◽  
Source Rocks ◽  
Yanchang Formation

Geochemical characteristics and sources of the crude oil of Yan’an formation Yan 9 in Zhao’an area, Ordos Basin, China

2019 ◽  
Vol 38 (3) ◽  
pp. 240-246 ◽  
Author(s):  
Yonghong He ◽  
Xiaoyan Fu ◽  
Tingyan Li ◽  
Xiujuan Wang ◽  
Yibo Chang ◽  
...  
Keyword(s):  
Crude Oil ◽  
Ordos Basin ◽  
Geochemical Characteristics

Study on the distribution of extractable organic matter in pores of lacustrine shale: An example of Zhangjiatan Shale from the Upper Triassic Yanchang Formation, Ordos Basin, China

2017 ◽  
Vol 5 (2) ◽  
pp. SF109-SF126 ◽  
Author(s):  
Yuxi Yu ◽  
Xiaorong Luo ◽  
Ming Cheng ◽  
Yuhong Lei ◽  
Xiangzeng Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Storage Capacity ◽  
Ordos Basin ◽  
Organic Content ◽  
Capacity Control ◽  
Yanchang Formation ◽  
Geochemical Characterization ◽  
Extractable Organic Matter

Shale oil and gas have been discovered in the lacustrine Zhangjiatan Shale in the southern Ordos Basin, China. To study the distribution of extractable organic matter (EOM) in the Zhangjiatan Shale ([Formula: see text] ranges from 1.25% to 1.28%), geochemical characterization of core samples of different lithologies, scanning electron microscope observations, low-pressure [Formula: see text] and [Formula: see text] adsorption, and helium pycnometry were conducted. The content and saturation of the EOM in the pores were quantitatively characterized. The results show that the distribution of the EOM in the shale interval is heterogeneous. In general, the shale layers have a higher EOM content and saturation than siltstone layers. The total organic content and the original storage capacity control the EOM content in the shale layers. For the siltstone layers, the EOM content is mainly determined by the original storage capacity. On average, 75% of the EOM occurs in the mesopores, followed by 14% in the macropores, and 11% in the micropores. The EOM saturation in the pores decreases with the increase in pore diameter. The distribution of EOM in the shale pores is closely related to the pore type. Micropores and mesopores developed in the kerogens and pyrobitumens and the clay-mineral pores coated with organic matter are most favorable for EOM retention and charging.

Sign in / Sign up

Export Citation Format

Share Document