Source Rocks Sedimentary Environment and Hydrocarbon Generating Potential of the Lower Cambrian in Kalpin Thrust Belt

The Afghan-Tajik Basin is an intermontane depression between the mountain ranges of Gissar and Pamirs, and Jurassic system and Tertiary system are rich in large oil & gas resources. In order to assure sustainable supply of oil & gas from Central Asia, we deeply researched hydrocarbon geology characteristics and resource potentials. The basin belongs to paralic sedimentary environment, and develops 3 sedimentary strata: Jurassic, Cretaceous, and Tertiary. Afghan-Tajik Basin develops 3 main source rocks including clastic rocks of Jurassic, carbonate rocks of Cretaceous and mudstone rocks of Eocene. The basin develops 2 plays: Jurassic-Cretaceous play is gas containing one, and Tertiary play is oil containing one. Plaster stone and salt rock of upper Jurassic are regional cap rocks of Jurassic-Cretaceous gas pool, and creaming mudstone and muddy limestone of Cretaceous and Tertiary are regional or partial cap rocks. Migration and accumulation of hydrocarbon occur in the late Cretaceous and early Pliocene epoch. Afghan-Tajik Basin has larger exploration potentials, and residual resources are 2.4¡Á108t. The potential zones are as follows, south part of basin, oil-gas structures of post-salt, reef limestone of pre-salt, and litho-stratigraphic traps.

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Characteristics of Rearranged Hopanes of Hydrocarbon Source Rocks in Saline Sedimentary Environment: A Case Study of the Songliao Basin

Acta Geologica Sinica - English Edition ◽

10.1111/1755-6724.13040 ◽

2016 ◽

Vol 90 (6) ◽

pp. 2269-2270 ◽

Cited By ~ 2

Author(s):

Lian JIANG ◽

Min ZHANG ◽

Hongbo LI ◽

Qilin XIAO

Keyword(s):

Sedimentary Environment ◽

Songliao Basin ◽

Source Rocks ◽

Hydrocarbon Source Rocks

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Geology and transitional shale gas resource potentials in the Ningwu Basin, China

Energy Exploration & Exploitation ◽

10.1177/0144598718772316 ◽

2018 ◽

Vol 36 (6) ◽

pp. 1482-1497

Author(s):

Qiang Xu ◽

Fengyin Xu ◽

Bo Jiang ◽

Yue Zhao ◽

Xin Zhao ◽

...

Keyword(s):

Shale Gas ◽

Vitrinite Reflectance ◽

Sedimentary Environment ◽

Organic Content ◽

Source Rocks ◽

Organic Carbon Content ◽

Lower Paleozoic ◽

Gas Source ◽

Average Porosity ◽

Pore Types

We analyzed the tectonic evolution characteristics, sedimentary environment, geochemical characteristics, petrological characteristics, and gas-bearing properties of three mudstone sections of the Lower Paleozoic in Ningwu Basin, NE China, and determined the geologic characteristics and resource potential of the transitional facies shale gas. Geochemical analysis of the organic carbon content, kerogen macerals, and vitrinite reflectance of the shale samples showed that the total organic content was generally over 2.0%, the main organic type was type III, and the vitrinite reflectance values (Ro) were between 1.20 and 1.90%. Thus, the mudstones are good shale gas source rocks. The thickness of the three mudstone sections was approximately 30–70 m, and the average porosity was 3.10%. The pore types were diverse with good reservoir capacity. The shale gas resources of the Carboniferous-Permian transitional facies estimated by the volumetric method were approximately 2798.97 × 108–4643.09 × 108 m3. Through a comparison with shales in SW China, where shale gas has been successfully exploited, we determined the preferred criteria for favorable shale gas areas, as well as favorable areas for shale gas enrichment.

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O CONGLOMERADO SAMBURÁ (GRUPO BAMBUÍ, NEOPROTEROZÓICO) E ROCHAS SEDIMENTARES ASSOCIADAS NO FLANCO LESTE DA SERRA DA PIMENTA, SW DE MINAS GERAIS: UM SISTEMA DE FAN DELTA.

Revista Geonomos ◽

10.18285/geonomos.v3i2.207 ◽

1995 ◽

Cited By ~ 1

Author(s):

Paulo de Tarso Amorin Castro ◽

Marcel Auguste Dardenne

Keyword(s):

Source Rocks ◽

Petrographic Analysis ◽

Eastern Region ◽

Thrust Belt ◽

Shallow Marine ◽

Metasedimentary Rocks ◽

Fan Delta ◽

Marine Carbonate ◽

Marine Carbonate Rocks ◽

Southwest Part

In the southwest part of São Francisco Craton occur neoproterozoic metasedimentary rocks of the Bambuí Group. Among these rocks the Samburá Conglomerate outcrops nearby the external (eastern) region of the southernmost part of Brasilia Thrust Belt. Sedimentological studies carried on these rocks at Serra da Pimenta region reveals that they belong to a fan delta system developed at the toes of thrust fault escarpments of Brasilia Thrust Belt. Petrographic analysis of clasts of Samburá Conglomerate pointed to Canastra Group and Pium-í greenstone belt rocks of Serra da Pimenta mountains as source rocks. The fan delta deposits are rested above shallow marine carbonate rocks of the base of Bambuí Group.

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Triassic Low Temperature Hydrothermal Activities(LTHA) From the Ordos Basin of Northern China

10.21203/rs.3.rs-227659/v1 ◽

2021 ◽

Author(s):

Jiyuan You ◽

Yiqun Liu ◽

Dingwu Zhou ◽

Yiyao Yang

Keyword(s):

Hydrothermal Vents ◽

Sedimentary Environment ◽

Ordos Basin ◽

Sedimentary Rocks ◽

Northern China ◽

Source Rocks ◽

Three Samples ◽

The Ordos Basin ◽

Hydrothermal Activities

Abstract Because few well-preserved hydrothermal channels have been found in terrestrial sedimentary rocks, research on LTHA in geological history is relatively sparse. In this study, we present our original discovery of “hydrothermal channels” from the Chang 7 source rocks of the Triassic Yanchang Formation in the Ordos Basin, China, and provide the best evidence for deciphering LTHA preserved in the geological record (i.e., sedimentary rocks). Three possible LTHA samples (i.e., samples 1551.6, 1551.6-2 and 1574.4) were collected for this study; they were interbedded with mudstones and oil shales, indicative of a deep-lake sedimentary environment. All three samples consist mainly of anhydrite, pyrite, and dolomite with the formation of mineral zoning across the walls of these structures, suggesting a sulfate-dominated stage and a carbonate-sulfide replacement stage. Moreover, their in situ geochemistry is characterized by high Eu, U, Th, Sr, Mn and U/Th ratios, which are typical indicators of hydrothermal vents. In addition, their S isotopes range from 7.89% to 10.88%, the magmatic sulfur accounted for approximately 94.3%, implying a possible magmatic trigger for these hydrothermal channels. All this evidence shows that the Triassic sedimentary rocks of the Ordos Basin probably contain LTHA. Comparing ancient LTHA to modern hydrothermal chimneys, we should note the important implications of LTHA; their formation mechanism may have been related to oil production, and they are possible indicators for future oil investigations. Further, they have great significance for studying the hydrothermal properties of primary dolomite.

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

Interpretation ◽

10.1190/int-2020-0158.1 ◽

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.

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