The Study on Hydrous Pyrolysis Experiments of Coal-Measure Source Rocks in Ordos Basin

2013 ◽  
Vol 734-737 ◽  
pp. 8-12
Author(s):  
Pei Xue ◽  
Yan Bin Wang ◽  
Jun Yuan
Keyword(s):  
Carbon Dioxide ◽  
Temperature Rise ◽  
Heating Temperature ◽  
Ordos Basin ◽  
Source Rocks ◽  
Coal Measure ◽  
Hydrocarbon Gases ◽  
Hydrous Pyrolysis ◽  
Hydrocarbon Gas ◽  
Hydrocarbon Productivity

Through the hydrous pyrolysis experiments of coal-measure source rocks in Taiyuan formation in Ordos Basin with different mediums from 250 °C to 550 °C, with a stepwise heating stage of 50 °C, the characteristics of gas and liquid products are discussed systematically in this paper. The results show that the change rule of hydrocarbon productivity of coal with temperature is similar to mudstone. Total hydrocarbon productivity and gas hydrocarbon productivity increase with temperature rise. Liquid hydrocarbon productivity increases with temperature rise first and then decreases. The peak yield of oil of coal appears at the heating temperature 350 °C, mudstone at 375 °C. The peak yield of mudstone lags behind. The non-hydrocarbon gas productivity increases with temperature rise. The non-hydrocarbon gases are carbon dioxide, nitrogen gas and oxygen mainly. The productivity of carbon dioxide is significantly higher than other non-hydrocarbon gas productivities. The main hydrocarbon gas is methane. The productivity of methane increases when temperature rises. And the productivity increases obviously after 400 °C.

Non-hydrocarbons of significance in petroleum exploration: volatile fatty acids and non-hydrocarbon gases

1987 ◽  
Vol 51 (362) ◽  
pp. 483-493 ◽  
Author(s):  
G. P. Cooles ◽  
A. S. Mackenzie ◽  
R. J. Parkes
Keyword(s):  
Volatile Fatty Acids ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Gas Generation ◽  
Hydrocarbon Gases ◽  
Natural Systems ◽  
Gaseous Products ◽  
Hydrous Pyrolysis ◽  
Hydrocarbon Gas ◽  
Thermodynamic Effects

AbstractNon-hydrocarbon gas species (CO2, N2, H2) are locally important in exploration for gas, and there is a growing body of evidence that acid water originating in shales materially affects the diagenesis of nearby sandstones. These gases have been studied by analysing the products of closed-vessel hydrous pyrolysis of known petroleum source rocks, and comparing the results with field observations. Alteration of petroleum source rocks at temperatures >250°C yields a significant amount of non-hydrocarbon components. Ethanoate and higher acid anions are liberated in substantial quantities; the yield appears to be related to the oxygen content of the sedimentary organic matter present.The non-hydrocarbon gases CO2, H2and N2are frequently the dominant gaseous products from hydrous pyrolysis: in the natural environment the same rock sequences at a higher maturity preferentially generate hydrocarbon gases—mainly methane. This discrepancy may be attributed to reaction and phase thermodynamic effects between laboratory and natural systems, behaviour that has important implications in the prediction of gas generation and composition in nature by source rock pyrolysis in the laboratory.

A QUEST FOR A NEW PARAMETER IN PETROLEUM EXPLORATION GEOCHEMISTRY

1987 ◽  
Vol 27 (1) ◽  
pp. 98 ◽  
Author(s):  
J.W. Smith ◽  
T.D. Gilbert
Keyword(s):  
Critical Factor ◽  
Liquid Hydrocarbon ◽  
General Concept ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Hydrocarbon Gases ◽  
Petrographic Composition ◽  
Exploration Geochemistry ◽  
Hydrous Pyrolysis ◽  
Rock Parameters

Primary Australian terrestrially-derived crudes are characterised by high wax and n-alkane contents. These characteristics, as determined by hydrogenation and hydrous pyrolysis, appear to be unrelated to either the chemical or petrographic compositions of Victorian brown coal lithotypes. Furthermore, since relationships between chemical and petrographic composition are obscure, a re-examination of current concepts which relate these established source rock parameters to liquid hydrocarbon generating potentials is warranted.The content of thermally stable, longer-chain, n-alkyl components in source rocks is introduced as the critical factor in determining whether these rocks have the potential to generate typical Australian waxy crudes or hydrocarbon gases. Modifications to this general concept are required by the thermal stability of directly substituted longer-chain n-alkyl aromatics and hydroaromatics. These appear to be sources of light hydrocarbons and gases, rather than oils.Inherent weaknesses in the experimental techniques of hydrogenation and hydrous pyrolysis have hindered the collection of data, but the concept that n-alkane potential is a critical factor in determining the petroleum-generating potential of immature source rocks is being pursued using techniques modified for the determination of their total heteroatom-bonded n-alkyl contents.

Investigation of geochemical characteristics of hydrocarbon gas and its implications for Late Miocene transpressional strength — A study in the Fangzheng Basin, Northeast China

2018 ◽  
Vol 6 (1) ◽  
pp. T83-T96 ◽  
Author(s):  
Bo Liu ◽  
Dongqi Yan ◽  
Xiaofei Fu ◽  
Yanfang Lü ◽  
Lei Gong ◽  
...  
Keyword(s):  
Late Miocene ◽  
Stable Carbon Isotopes ◽  
Active Faults ◽  
Source Rocks ◽  
Type Ii ◽  
Gas Generation ◽  
Hydrocarbon Gases ◽  
Type Iii ◽  
Wet Gas ◽  
Hydrocarbon Gas

We have assessed the genetic types of hydrocarbon gas in the Fangzheng Basin by analyzing the effects of geologic settings on gas generation, kerogen types in source rocks, gas compositions, stable carbon isotopes of individual alkanes, and biomarkers in gas-associated oil. The primary compounds of source rocks in the Eocene Xinancun Formation and Paleocene Wuyun Formation are found as type II and III kerogens, respectively. The hydrocarbon gas in the Fangzheng Basin can be classified into three families. Family I is affected by biodegradation, and it is dry gas generated from low-maturity lacustrine mudstones (i.e., oil-prone source rocks) of the Xinancun Formation. Family II is coal-derived wet gas accompanied by oil, and it is typically generated by type III kerogen of mudstones in coal measures of the Wuyun Formation. Family III is mixed-type wet gas whose primary compound is oil-associated gas, and it is mainly generated by type II kerogen in the Xinancun Formation and partly from type III kerogen in the Wuyun Formation in the Daluomi (DLM) Uplift. The family I and II hydrocarbon gases are located in the Zhuozhugang (ZSG) Sag. Family III hydrocarbon gas was formed in the mixing process of different genesis gas through the active faults because the late Miocene transpressional strength of uplift in the DLM Uplift was more intense than that in the ZSG Sag after the development of increased accommodation space coeval with intrabasinal rifting before Oligocene.

Generation and origin of natural gas in Lower Palaeozoic shales from southern Sweden

1969 ◽  
pp. 37-40
Author(s):  
Niels Hemmingsen Schovsbo ◽  
Arne Thorshøj Nielsen
Keyword(s):  
Source Rocks ◽  
Southern Sweden ◽  
Hydrocarbon Gases ◽  
Biogenic Gas ◽  
South Central ◽  
Alum Shale ◽  
Marine Source ◽  
Lower Palaeozoic ◽  
Background Gas ◽  
Origin Of Natural Gas

The Lower Palaeozoic succession in Scandinavia includes several excellent marine source rocks notably the Alum Shale, the Dicellograptus shale and the Rastrites Shale that have been targets for shale gas exploration since 2008. We here report on samples of these source rocks from cored shallow scientific wells in southern Sweden. The samples contain both free and sorbed hydrocarbon gases with concentrations significantly above the background gas level. The gases consist of a mixture of thermogenic and bacterially derived gas. The latter likely derives from both carbonate reduction and methyl fermentation processes. The presence of both thermogenic and biogenic gas in the Lower Palaeozoic shales is in agreement with results from past and present exploration activities; thermogenic gas is a target in deeply buried, gas-mature shales in southernmost Sweden, Denmark and northern Poland, whereas biogenic gas is a target in shallow, immature-marginally mature shales in south central Sweden. We here document that biogenic gas signatures are present also in gas-mature shallow buried shales in Skåne in southernmost Sweden.

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