GAS CONTENT APPRAISAL OF SHALLOW COAL SEAMS IN THE SOUTH PALEMBANG BASIN OF SOUTH SUMATRA

2017 ◽  
Author(s):  
Ana Asmina
Keyword(s):  
Gas Content ◽  
The South ◽  
Coal Seams

scholarly journals Study on Reservoir Properties and Critical Depth in Deep Coal Seams in Qinshui Basin, China

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Guiqiang Zheng ◽  
Bin Sun ◽  
Dawei Lv ◽  
Zhejun Pan ◽  
Huiqing Lian
Keyword(s):  
Coal Seam ◽  
Step Change ◽  
Gas Content ◽  
Burial Depth ◽  
Critical Depth ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Qinshui Basin ◽  
Geological Conditions ◽  
Change Characteristics

Coalbed methane (CBM) reservoir properties and relationship of properties with burial depth were studied based on the data derived from 204 deep CBM production wells in Qinshui Basin, China. Through the study, it is found that permeability and porosity decrease with the increase of burial depth and the decreasing trend shows step-change characteristics at a critical burial depth. They also show divisional characteristics at certain burial depth. Gas content, geostress, and geotemperature increase with the increase of burial depth, and the increasing trend shows step-change characteristics and also have divisional characteristics at certain burial depth. Based on the previous study on the reservoir property changes with burial depth, three series of critical depth using different parameters are obtained through simulating the critical depth using the BP neural network method. It is found that the critical depth is different when using different parameters. Combined the previous study with the normalization of three different parameter types, the critical depth in Qinshui Basin was defined as shallow coal seam is lower than 650 m and transition band is 650–1000 m, while deep coal seam is deeper than 1000 m. In deep coal seams, the geological conditions and recovery becomes poor, so it can be defined as unfavorable zones. Therefore, other development means, for example, CO2 injection, need to be used to accelerate the deep coal methane development.

scholarly journals CBM Resources Estimations for the Development of Coal Mine Methane in the Asturian Central Basin, Spain

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1404
Author(s):  
Pablo Cienfuegos-Suárez ◽  
Efrén García-Ordiales ◽  
Diego Alonso-Fernández ◽  
Jorge Enrique Soto-Yen
Keyword(s):  
Coal Mine ◽  
Coalbed Methane ◽  
Technological Development ◽  
Gas Content ◽  
Central Basin ◽  
Economic Interest ◽  
Coal Seams ◽  
Coal Basin ◽  
Coal Mine Methane ◽  
Made In

New technological development and a best knowledge of the basin allow to have justified expectation to find coalbed methane reserves. Measurements of gas content in unexploited coal seams are made in order to estimate the CBM could revive the economic interest of the Asturian Central Coal Basin (ACCB). According to first estimations based on the studies accomplished, the minimum resources of coalbed methane in the whole of the Asturian Central Coal Basin are in the order of 25,000 Mm3 and the gas content of the coal seams range from 6 m3 to 14 m3/t. The introduction should briefly place the study in a broad context and define the purpose of the work and its significance.

scholarly journals Controls on Gas Domains and Production Behaviour in A High-Rank CSG Reservoir: Insights from Molecular and Isotopic Chemistry of Co-Produced Waters and Gases from the Bowen Basin, Australia

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 74 ◽  
Author(s):  
Stephanie K. Hamilton ◽  
Suzanne D. Golding ◽  
Joan S. Esterle ◽  
Kim A. Baublys ◽  
Brycson B. Ruyobya
Keyword(s):  
Carbon Isotope ◽  
Vitrinite Reflectance ◽  
Isotope Analysis ◽  
Co2 Reduction ◽  
Production Performance ◽  
High Rank ◽  
Gas Content ◽  
Coal Seams ◽  
Gas Generation ◽  
Geographic Variations

This paper uses hydrochemical and multi-isotope analysis to investigate geological controls on coal seam gas (CSG) saturation domains and gas well production performance in a high-rank (vitrinite reflectance (Rv) > 1.1) CSG field in the north-western Bowen Basin, Australia. New hydrochemical and stable isotope data were combined with existing geochemical datasets to refine hypotheses on the distribution and origins of CSG in two highly compartmentalized Permian coal seams. Stable isotopic results suggest that geographic variations in gas content, saturation and production reflect the extent of secondary microbial gas generation and retention as a function of hydrodynamics. δ13C and δ2H data support a gas mixing hypothesis with δ13C-CH4 increasing from secondary biogenic values to thermogenic values at depth (δ13C −62.2‰ to −46.3‰), whereas correlated methane and carbon dioxide carbon isotope compositions, Δ13C(CO2–CH4) values and δ13CDIC/alkalinity trends are largely consistent with microbial CO2 reduction. In addition, below 200 m, the majority of δ13C-CO2 values are positive (δ13C: −1.2‰ to 7.1‰) and δ13CDIC shows an erratic increase with depth for both seams that is characteristic of evolution via microbial activity. The progression of carbon isotope values along the CO2 reduction fractionation line suggests progressive depletion of the CO2 reservoir with increasing depth. Faults clearly segment coal seams into areas having significantly different production, with results of geochemical analysis suggesting that pooling of biogenic gas and waters and enhanced methanogenesis occur north of a faulted hinge zone.

scholarly journals Study on geological controls and enrichment models of coalbed methane in the Wuwei Basin in eastern North Qilian, northwestern China

2018 ◽  
Vol 37 (1) ◽  
pp. 429-452
Author(s):  
Wenchao Shen ◽  
Longyi Shao ◽  
Wenguang Tian ◽  
Gang Chen ◽  
Fei Chen ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Sedimentary Environment ◽  
Controlling Factors ◽  
Gas Content ◽  
Methane Formation ◽  
Coal Seams ◽  
Mineral Contents ◽  
The North ◽  
Taiyuan Formation ◽  
Lagoon Environment

The Wuwei Basin is located in the Gansu Corridor, which has abundant coalbed methane resources of 2.75 × 1011 m3. However, a low degree of coalbed methane exploration exists, and only a few wells have been drilled in local regions due to insufficient understanding of coalbed methane enrichment and its main controlling factors. This study analyzed the controlling factors of coalbed methane enrichment, including coal reservoir characteristics, hydrogeological conditions, and the original sedimentary environment of the coal-bearing strata. The results showed that the main coal seams were developed in the Taiyuan Formation, and were mostly concentrated in the Yingpan Sag in the south and the Ermahu Sag in the north of the study area. The macrolithotype of the coals in this basin was mainly semi-bright coal with a medium to high rank. Coal macerals were mainly vitrinite, ranging between 65.1% and 91.6% (averaged 81.70%), followed by liptinite, ranging between 1.9% and 29.5% (averaged 8.82%), and inertinite, ranging between 0.2% and 16.5% (averaged 3.66%). Mineral contents varied from 2.5% to 15.1% (averaged 6.16%). The macrolithotype and microlithotype of the Taiyuan Formation coals were favorable for coalbed methane formation. Through comparative analysis of moisture content, ash yield, gas content, and coal-forming sedimentary environments, it was found that the coal formed in the lagoon environment had a higher gas content and lower ash yield than that of the coal formed in the tidal flat environment. The high contents of total dissolved solids in aquifers around coal seams (1.75–16.70 g/L) reflected the closed hydrodynamic environment and were favorable for the preservation of coalbed methane in the Yingpan Sag. Considering various controlling factors (i.e., structure, sedimentation and hydrogeology), three coalbed methane enrichment models were proposed. The model of coalbed methane enrichment in the synclinorium was the most favorable for the enrichment of coalbed methane in the Yingpan Sag.

Fine Description and Development Strategy of Fort Cooper Coal Measures in North Bowen Basin of Australia

2014 ◽  
Vol 1030-1032 ◽  
pp. 1309-1313
Author(s):  
Ze Hong Cui ◽  
Bin Ren ◽  
Zhao Hui Xia ◽  
Ming Zhang ◽  
Wei Ding ◽  
...  
Keyword(s):  
Development Strategy ◽  
Ash Content ◽  
Gas Content ◽  
Western Slope ◽  
High Permeability ◽  
Coal Seams ◽  
Block Effect ◽  
Development Evaluation ◽  
Coal Measures ◽  
Favorable Area

Based on the analysis of coring, logging and experimental data, fine evaluation on Fort Copper Coal Measures (FCCM) of Early Permian Blackwater Group in north Bowen Basin of Australia has been done. FCCM is a potential coal measure. Eight coal seams exist in FCCM. Laterally, they develop steadily. Seams of FCCM characterize interbedding with partings, high ash content, high gas content and mediate-low permeability. The content of partings, which are groups of siltstone, mudstone and tuff, ranges from 15% to 55%. The cumulative thickness of pure coal ranges from 40 to 60 m. The ash content ranges from 20% to 70%, averaging 45%. Coal seams gas content is as high as 7% to 15%, benefitting from the dense rock block effect on the top and bottom, as well as the interplayers. The permeability ranges from 0.1 to 10 mD laterally. Parameters above show FCCM has good developing potential. Western slope of Nebo syncline is suggested as the favorable area, considering its good developing factors such as shallow buried depth of coal seams, relatively high permeability and effective gas preserve environment. Meanwhile, gas in partings can be considered in collaborative development strategy. Developing gas along with ash will be the focus of future development evaluation.

The Studies on Gas-Bearing Characteristics of Deep Coal Seams in Yanchang Oil and Gas Province, China

2014 ◽  
Vol 962-965 ◽  
pp. 213-216
Author(s):  
Guo Ping Jiang
Keyword(s):  
Coal Seam ◽  
Layer Thickness ◽  
Oil And Gas ◽  
Single Layer ◽  
Gas Content ◽  
Coal Bed ◽  
Coal Seams ◽  
Resource Potential ◽  
Gas Bearing ◽  
Average Layer Thickness

In this paper, four general directions are described to make evaluations and their resource potential; those are coal structure and coal level, gas content of deep coalbed, the coalbed thickness and distribution and the buried depth of coalbed. Coalfields of the study area are mainly Permian and Carboniferous coal seam of Shanxi Formation coal and Benxi group 11 # coal, coal seam depth 1370-1812m. No. 3 coal-seam average layer thickness of 1.6 m, the monolayer most 2 m thick; No. 11 coal-seam in the average layer thickness of 3 m, single-layer thickness of 4.5 m. Predict the amount of coal resources of 17.3 one hundred million t. Predict coal-bed methane resources of 27.68 billion cubic reserve abundance of 104 million square / km2 in. The exploration results show that this region has good development prospects.

scholarly journals Nitrogen Injection To Flush Coal Seam Gas Out Of Coal: An Experimental Study

2015 ◽  
Vol 60 (4) ◽  
pp. 1013-1028 ◽  
Author(s):  
Lei Zhang ◽  
Naj Aziz ◽  
Ting Ren ◽  
Jan Nemcik ◽  
Shihao Tu
Keyword(s):  
Coal Seam ◽  
Clean Energy ◽  
Gas Content ◽  
Coal Seams ◽  
Coal Seam Gas ◽  
Gas Recovery ◽  
Nitrogen Injection ◽  
Gas Desorption ◽  
Effective Role ◽  
Study Laboratory

Abstract Several mines operating in the Bulli seam of the Sydney Basin in NSW, Australia are experiencing difficulties in reducing gas content within the available drainage lead time in various sections of the coal deposit. Increased density of drainage boreholes has proven to be ineffective, particularly in sections of the coal seam rich in CO2. Plus with the increasing worldwide concern on green house gas reduction and clean energy utilisation, significant attention is paid to develop a more practical and economical method of enhancing the gas recovery from coal seams. A technology based on N2 injection was proposed to flush the Coal Seam Gas (CSG) out of coal and enhance the gas drainage process. In this study, laboratory tests on CO2 and CH4 gas recovery from coal by N2 injection are described and results show that N2 flushing has a significant impact on the CO2 and CH4 desorption and removal from coal. During the flushing stage, it was found that N2 flushing plays a more effective role in reducing adsorbed CH4 than CO2. Comparatively, during the desorption stage, the study shows gas desorption after N2 flushing plays a more effective role in reducing adsorbed CO2 than CH4.

On determining coal classification indicators for establishing dangerous properties of mines

2020 ◽  
pp. 149-159
Author(s):  
М. Antoshchenko ◽  
◽  
V. Tarasov ◽  
R. Zaika ◽  
O. Zolotarova ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Organic Matter ◽  
Fire Hazard ◽  
Coal Dust ◽  
Gas Content ◽  
Technological Parameters ◽  
Coal Seams ◽  
Volatile Substances ◽  
Main Indicator ◽  
Seam Mining

Currently, more than 20 qualification indicators are known by which degree of metamorphic coal transformations are established. Most of these indicators are designed for determining technological properties with industrial use of coal in mind. Due to sufficient knowledge of the indicators used, industrial classifications are constantly being improved. The modern classification by genetic and technological parameters groups the coals by the grades based on ten indicators. Of these, only one - the mass yield of volatile substances during the thermal decomposition of coal - is used as the main indicator of the manifestation of dangerous properties of coal seams without due scientific justification. Dangerous properties of coal seams during mining include: gas content of coal, a tendency to gas-dynamic phenomena and spontaneous combustion, dust forming ability and explosiveness of coal dust. In industrial classifications, the main indicator is determined for the dry ash-free state of organic matter. Manifestation of dangerous properties of coal seams occurs in the presence of both moisture and mineral impurities. This fact is not taken into account by other auxiliary indicators used to predict the hazardous properties of coal seams. Moisture in coal seams is in at least four states, and it is completely removed while analyzing the samples and is not taken into account in volatile products of thermal decomposition of coal. Thus, when using the indicator of mass output of volatile substances, influence of moisture in any form of its presence in coal on the occurrence of emergency situations is automatically ignored. The probability of emergencies during mining is largely determined by the ratio between components of organic mass (C, O, H, S, N) and mineral impurities. It is also not taken into account in normative documents which regulate safety of coal seam mining. The classification indicators defined in different ways characterize different aspects of coal conversion in metamorphic processes. Volatiles yield and average vitrine reflectance, well studied in industrial applications, correspond to different aspects of degree of conversion of starting organic matter. In order to establish dangerous properties of coal seams, their mutual substitution is unacceptable, which is confirmed by nonlinear connection between them. The existence of a genetic relationship between the outburst and fire hazard of coal seams has been established. This indicates the need to develop a unified classification of the hazardous properties of coal seams by genetic, mining engineering and geological parameters. The scientifically substantiated use in regulatory documents of a set of classification indicators that directly characterize the manifestations of the hazardous properties of coal seams will help to reduce number of accidents and injuries in coal mines.

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