scholarly journals Characteristics and the Model of Thermal Evolution and Gas Generation of Late Paleozoic Coal in the Qinshui Basin, Based on Hydrous Pyrolysis

ACS Omega ◽  
2021 ◽  
Author(s):  
Ruilin Hao ◽  
Wenhui Huang ◽  
Bo Jiu
Keyword(s):  
Thermal Evolution ◽  
Late Paleozoic ◽  
Gas Generation ◽  
Qinshui Basin ◽  
Hydrous Pyrolysis

Evidence from the Changing Carbon Isotopic of Kerogen, Oil, and Gas during Hydrous Pyrolysis from Pinghu Formation, the Xihu Sag, East China Sea Basin

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8317
Author(s):  
Qiang Cao ◽  
Jiaren Ye ◽  
Yongchao Lu ◽  
Yang Tian ◽  
Jinshui Liu ◽  
...  
Keyword(s):  
Carbon Isotopes ◽  
Oil And Gas ◽  
Thermal Evolution ◽  
Vitrinite Reflectance ◽  
Heating Time ◽  
Source Rocks ◽  
Evolution Process ◽  
Carbon Isotopic ◽  
Hydrous Pyrolysis ◽  
Increasing Temperature

Semi-open hydrous pyrolysis experiments on coal-measure source rocks in the Xihu Sag were conducted to investigate the carbon isotope evolution of kerogen, bitumen, generated expelled oil, and gases with increasing thermal maturity. Seven corresponding experiments were conducted at 335 °C, 360 °C, 400 °C, 455 °C, 480 °C, 525 °C, and 575 °C, while other experimental factors, such as the heating time and rate, lithostatic and hydrodynamic pressures, and columnar original samples were kept the same. The results show that the simulated temperatures were positive for the measured vitrinite reflectance (Ro), with a correlation coefficient (R2) of 0.9861. With increasing temperatures, lower maturity, maturity, higher maturity, and post-maturity stages occurred at simulated temperatures (Ts) of 335–360 °C, 360–400 °C, 400–480 °C, and 480–575 °C, respectively. The increasing gas hydrocarbons with increasing temperature reflected the higher gas potential. Moreover, the carbon isotopes of kerogen, bitumen, expelled oil, and gases were associated with increased temperatures; among gases, methane was the most sensitive to maturity. Ignoring the intermediate reaction process, the thermal evolution process can be summarized as kerogen0(original) + bitumen0(original)→kerogenr (residual kerogen) + expelled oil (generated) + bitumenn+r (generated + residual) + C2+(generated + residual) + CH4(generated). Among these, bitumen, expelled oil, and C2-5 acted as reactants and products, whereas kerogen and methane were the reactants and products, respectively. Furthermore, the order of the carbon isotopes during the thermal evolution process was identified as: δ13C1 < 13C2-5 < δ13Cexpelled oil < δ13Cbitumen < δ13Ckerogen. Thus, the reaction and production mechanisms of carbon isotopes can be obtained based on their changing degree and yields in kerogen, bitumen, expelled oil, and gases. Furthermore, combining the analysis of the geochemical characteristics of the Pinghu Formation coal–oil-type gas in actual strata with these pyrolysis experiments, it was identified that this area also had substantial development potential. Therefore, this study provides theoretical support and guidance for the formation mechanism and exploration of oil and gas based on changing carbon isotopes.

scholarly journals The characteristics of hydrocarbon generation, reserving performances of fine-grained rock, and preservation conditions of coal measure shale gas of an epicontinental sea basin: A case study of the Late Palaeozoic shale gas in the Huanghebei Area of Western Shandong

2018 ◽  
Vol 37 (1) ◽  
pp. 453-472 ◽  
Author(s):  
Ying Li ◽  
Zengxue Li ◽  
Huaihong Wang ◽  
Dongdong Wang
Keyword(s):  
Coal Seam ◽  
Shale Gas ◽  
Late Paleozoic ◽  
Organic Carbon Content ◽  
Hydrocarbon Generation ◽  
Average Content ◽  
Gas Generation ◽  
Geological Structures ◽  
Fine Grained ◽  
Western Shandong

In China, marine and land transitional fine-grained rocks (shale, mudstone, and so on) are widely distributed and are known to have large accumulated thicknesses. However, shale gas explorations of these types of rock have only recently been initiated, thus the research degree is very low. Therefore, this study was conducted in order to improve the research data regarding the gas accumulation theory of marine and continental transitional fine-grained rock, as well as investigate the shale gas generation potential in the Late Paleozoic fine-grained rock masses located in the Huanghebei Area of western Shandong Province. The hydrocarbon generation characteristics of the epicontinental sea coal measures were examined using sedimentology, petrography, geochemistry, oil and gas geology, tectonics, and combined experimental testing processes. The thick fine-grained rocks were found to have been deposited in the sedimentary environments of the tidal flats, barriers, lagoons, deltas, and rivers during the Late Paleozoic in the study area. The most typical fine-grained rocks were located between the No. 5 coal seam of the Shanxi Formation and the No. 10 coal seam of the Taiyuan Formation, with an average thickness of 84.8 m. These formations were mainly distributed in the western section of the Huanghebei Area. The total organic carbon content level of the fine-grained rock was determined to be 2.09% on average, and the higher content levels were located in the western section of the Huanghebei Area. The main organic matter types of the fine-grained rock were observed to be kerogen II, followed by kerogen III. The vitrinite reflectance ( Ro) of the fine-grained rock was between 0.72 and 1.25%, which indicated that the gas generation of the dark fine-grained rock was within a favorable range, and the maturity of the rock was mainly in a medium stage in the northern section of the Huanghebei Area. It was determined that the average content of brittle minerals in the fine-grained rock was 55.7%. The dissolution pores and micro-cracks were the dominating pores in the fine-grained rock, followed by intergranular pores and intercrystalline pores. It was also found that both the porosity and permeability of the fine-grained rock were very low in the study area. The desorption gas content of the fine-grained rock was determined to be between 0.986 and 4.328 m3/t, with an average content of 2.66 m3/t. The geological structures were observed to be simple in the western section of the Huanghebei Area, and the occurrence impacts on the shale gas were minimal. However, the geological structures were found be complex in the eastern section of the study area, which was unfavorable for shale gas storage. The depths of the fine-grained rock were between 414.05 and 1290.55 m and were observed to become increasingly deeper from the southwestern section to the northern section. Generally speaking, there were found to be good reservoir forming conditions and great resource potential for marine and continental transitional shale gas in the study area.

Study on the Forming Conditions of Shale Gas in Coal Measure of Wuli Area, Qinghai Province, China

2013 ◽  
Vol 295-298 ◽  
pp. 2770-2773 ◽  
Author(s):  
Dai Yong Cao ◽  
Jing Li ◽  
Ying Chun Wei ◽  
Xiao Yu Zhang ◽  
Chong Jing Wang
Keyword(s):  
Shale Gas ◽  
Thermal Evolution ◽  
Organic Matter Content ◽  
Gas Production ◽  
Matter Content ◽  
Source Rocks ◽  
Coal Measure ◽  
Gas Generation ◽  
Qinghai Province ◽  
Coal Measures

Besides coal seam, the source rocks including dark mudstone, carbon mudstone and so on account for a large proportion in the coal measures. Based on the complex geothermal evolution history, the majority of coal measure organic matters with the peak of gas generation have a good potential of gas. Therefore, shale gas in coal measure is an important part of the shale gas resources. There are good conditions including the thickness of coal measures, high proportion of shale rocks, rich in organic matter content, high degree of thermal evolution, high content of brittle mineral and good conditions of the porosity and permeability for the generation of shale gas in Wuli area, the south of Qinghai province. Also the direct evidence of the gas production has been obtained from the borehole. The evaluation of shale gas in coal measure resources could broaden the understanding of the shale gas resources and promote the comprehensive development of the coal resources.

Burial and thermal evolution of coal-bearing strata and its mechanisms in the southern North China Basin since the late Paleozoic

2018 ◽  
Vol 198 ◽  
pp. 100-115 ◽  
Author(s):  
Kun Yu ◽  
Yiwen Ju ◽  
Jin Qian ◽  
Zhenghui Qu ◽  
Chunjing Shao ◽  
...  
Keyword(s):  
North China ◽  
Thermal Evolution ◽  
Late Paleozoic ◽  
North China Basin

Gas Generation Regularities of Dissipated Soluble Organic Matter in Sichuan Basin

2014 ◽  
Vol 977 ◽  
pp. 308-311
Author(s):  
Hai Tao Xue ◽  
Guo Dong Mu ◽  
Shan Si Tian ◽  
Shuang Fang Lu
Keyword(s):  
Organic Matter ◽  
Sichuan Basin ◽  
Thermal Evolution ◽  
Parent Material ◽  
Source Rocks ◽  
Soluble Organic Matter ◽  
Gas Generation ◽  
Marine Strata ◽  
Proper Order ◽  
Gas Generation Rate

The organic matter of marine strata has high degree of thermal evolution in Sichuan Basin. The gas generation ability of kerogen is very limited, which mainly relies on the soluble organic matter as gas parent material to provide gas source for gas reservoir. In this paper, chemical kinetics method and experiments are applied to study on the history of gas generation and gas generation rate of organic matter in Sichuan marine strata. Result shows that dissipated soluble organic matter in source rocks, dissipated soluble organic matter out of source rocks and organic matter in paleo-reservoir successively generate gas in proper order. Dissipated soluble organic matter out of source rocks and the oil in paleo-reservoir belong to late gas generation.

scholarly journals SILLi 1.0: A 1D Numerical Tool Quantifying the Thermal Effects of Sill Intrusions

2017 ◽  
Author(s):  
Karthik Iyer ◽  
Henrik Svensen ◽  
Daniel W. Schmid
Keyword(s):  
Thermal Effects ◽  
Thermal Evolution ◽  
Thermal Structure ◽  
Sedimentary Basins ◽  
Gas Generation ◽  
Porosity Evolution ◽  
Karoo Basin ◽  
Igneous Intrusions ◽  
User Friendly ◽  
Latent Heats

Abstract. Igneous intrusions in sedimentary basins may have a profound effect on the thermal structure and physical properties of the hosting sedimentary rocks. These include mechanical effects such as deformation and uplift of sedimentary layers, generation of overpressure, mineral reactions and porosity evolution, and fracturing and vent formation following devolatilization reactions and the generation of CO2 and CH4. The gas generation and subsequent migration and venting may have contributed to several of the past climatic changes such as the end-Permian event and the Paleocene-Eocene Thermal Maximum. Additionally, the generation and expulsion of hydrocarbons and cracking of pre-existing oil reservoirs around a hot magmatic intrusion is of significant interest to the energy industry. In this paper, we present a user-friendly 1D FEM based tool, SILLi, which calculates the thermal effects of sill intrusions on the enclosing sedimentary stratigraphy. The model is accompanied by three case studies of sills emplaced in two different sedimentary basins, the Karoo Basin in South Africa and the Vøring Basin offshore Norway. Input data for the model is the present-day well log or sedimentary column with an Excel input file and includes rock parameters such as thermal conductivity, total organic carbon (TOC) content, porosity, and latent heats. The model accounts for sedimentation and burial based on a rate calculated by the sedimentary layer thickness and age. Erosion of the sedimentary column is also included to account for realistic basin evolution. Multiple sills can be emplaced within the system with varying ages. The emplacement of a sill occurs instantaneously. The model can be applied to volcanic sedimentary basins occurring globally. The model output includes the thermal evolution of the sedimentary column through time, and the changes that take place following sill emplacement such as TOC changes, thermal maturity, and the amount of organic and carbonate-derived CO2. The TOC and vitrinite results can be readily benchmarked within the tool to present-day values measured within the sedimentary column. This allows the user to determine the conditions required to obtain results that match observables and leads to a better understanding of metamorphic processes in sedimentary basins.

scholarly journals Fine evaluation and favorable area prediction of deep source rocks in northern Songliao Basin

2021 ◽  
Vol 329 ◽  
pp. 01056
Author(s):  
Fan Zhang ◽  
Yanjie Li ◽  
Xiaoshan Ji ◽  
Qiuli Huo ◽  
Yuming Wu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Comprehensive Evaluation ◽  
Thermal Evolution ◽  
Songliao Basin ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Gas Generation ◽  
The North ◽  
Geological Conditions ◽  
Exploration Area

Focusing on Xujiaweizi fault depression, the geological conditions and geochemical characteristics of deep natural gas formation in the north of Songliao basin are evaluated, the natural gas resources are estimated, and the favorable areas are optimized. Shahezi Formation shale is a set of coal bearing sediments with high organic matter abundance (TOC is 1%～12%), high over maturity (Ro is 1%～4%) and shore shallow lake facies, which are mainly distributed in Xujiaweizi fault depression, Gulong-Lindian fault depression and Yingshan fault depression. The thickness, TOC, Ro and hydrocarbon generation of four thirdorder sequences with different lithology (mudstone and coal) are carefully evaluated for the Shahezi Formation shale in the deep layer of Songbei. The comprehensive evaluation shows that the mudstone thickness of Es4 member in Anda and Xuzhong areas of Xujiaweizi fault depression is large (150 ~ 525m), TOC is high (1% ~ 4%), thermal evolution degree is high (Ro is 1.2% ~ 3.4%), and gas generation intensity is high (20 ~ 815) × 108m3 / t), moderate buried depth (3000~4500m) and overlapping area of 756km2. It is a favorable exploration area for natural gas and shale gas in Daqing Oilfield.

Effects of rifting and subsidence on thermal evolution of sediments in Canada's east coast basins

1993 ◽  
Vol 30 (9) ◽  
pp. 1782-1798 ◽  
Author(s):  
S. A. Dehler ◽  
C. E. Keen
Keyword(s):  
Thermal Gradient ◽  
Thermal Evolution ◽  
Vitrinite Reflectance ◽  
Thermal Maturity ◽  
Sediment Thickness ◽  
Gas Generation ◽  
Lithospheric Deformation ◽  
Grand Banks ◽  
Lithospheric Extension ◽  
Nova Scotian

Regional maps of lithospheric deformation and thermal history have been derived for the eastern continental margin of Canada. Subsidence associated with the rifting and cooling stages of rifted margin formation was calculated from gridded maps of sediment thickness and bathymetry along the Labrador, Grand Banks, and Nova Scotian margins. A two-layer lithospheric extension model was used to compute the deformation and thermal evolution of each region. Deformation results show that the crust and lower lithosphere have generally stretched by different amounts, and that either crustal or subcrustal lithospheric stretching dominates beneath the various basins. Thermal modelling results for the older Nova Scotian and Grand Banks margins show a strong correlation between thermal gradient, crustal stretching, and sediment thickness, and the predicted thermal gradient pattern for the younger Labrador margin correlates extremely well with predicted stretching of the still-cooling subcrustal lithosphere. Predictions of sediment maturity (vitrinite reflectance) of basin deposits were obtained from the derived time – temperature histories. Model results have been constrained with observations from individual boreholes and extrapolated away from these well-constrained areas into regions beyond the frontiers of present exploration. Results are presented as maps showing depths to present-day peak thermal maturity zones and the ages at which earliest post-rift sediments reached peak maturity levels. This reconnaissance approach has led to predictions of thermal maturity zones suitable for oil or gas generation in western Orphan Basin and beneath the continental slopes.

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