Characterisation of Surat Basin Walloon interburden and overlying Springbok Sandstone: a focus on methane adsorption isotherms, permeability and gas content

2020 ◽  
Vol 60 (2) ◽  
pp. 748
Author(s):  
Syed Shabbar Raza ◽  
Julie Pearce ◽  
Pradeep Shukla ◽  
Phil Hayes ◽  
Victor Rudolph
Keyword(s):  
Adsorption Isotherms ◽  
Gas Adsorption ◽  
Methane Adsorption ◽  
Gas Content ◽  
Coal Seams ◽  
X Ray ◽  
Gas Desorption ◽  
Water Wells ◽  
Temperature And Pressure ◽  
Coal Measures

The Surat Basin in Queensland is one of the world’s premier producers of natural gas from coal seams. We investigate the potential for clay-rich Walloon Coal interburden and the overlying Springbok Sandstone to hold or produce gas. Seventeen core samples were analysed from two wells from intervals within the Walloon Upper Juandah Coal Measures interburden and the Springbok Sandstone. Samples were characterised using high-pressure methane adsorption isotherms, canister gas desorption tests, moisture contents, ash contents, carbon contents, scanning electron microscopy/energy dispersive X-ray spectrometry, X-ray quantitative clay analysis, permeability, helium pycnometry and mercury intrusion porosimetry. Methane adsorption was conducted at 30°C with up to 8 MPa pressure on dried crushed samples. The adsorption capacity of methane at 8 MPa varied from 3 cc/g (calcite-cemented) up to 25 cc/g (standard temperature and pressure equivalent) (coal). Clay-rich interburden samples adsorbed ~5–14 cc/g (dry). The measured isotherms and methane content from canister desorption tests show that appreciable volumes of gas are contained within some portions of interburden and in the overlying Springbok Sandstone. Gas within the interburden likely represents a large volumetric resource, albeit in low permeability rock that restricts direct productivity. The gas adsorption and gas content results for the Springbok Sandstone help to explain field observations of high gas content in some landholder water wells.

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.

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.

Modeling Gas Adsorption in Marcellus Shale With Langmuir and BET Isotherms

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 589-600 ◽  
Author(s):  
Wei Yu ◽  
Kamy Sepehrnoori ◽  
Tadeusz W. Patzek
Keyword(s):  
Shale Gas ◽  
Langmuir Isotherm ◽  
History Matching ◽  
Gas Adsorption ◽  
Marcellus Shale ◽  
Methane Adsorption ◽  
Gas Reservoirs ◽  
Gas Desorption ◽  
Shale Gas Reservoirs ◽  
Bet Isotherm

Summary Production from shale-gas reservoirs plays an important role in natural-gas supply in the United States. Horizontal drilling and multistage hydraulic fracturing are the two key enabling technologies for the economic development of these shale-gas reservoirs. It is believed that gas in shale reservoirs is mainly composed of free gas within fractures and pores and adsorbed gas in organic matter (kerogen). It is generally assumed in the literature that the monolayer Langmuir isotherm describes gas-adsorption behavior in shale-gas reservoirs. However, in this work, we analyzed four experimental measurements of methane adsorption from the Marcellus Shale core samples that deviate from the Langmuir isotherm, but obey the Brunauer-Emmett-Teller (BET) isotherm. To the best of our knowledge, it is the first time to find that methane adsorption in a shale-gas reservoir behaves similar to multilayer adsorption. Consequently, investigation of this specific gas-desorption effect is important for accurate evaluation of well performance and completion effectiveness in shale-gas reservoirs on the basis of the BET isotherm. The difference in calculating original gas in place (OGIP) on the basis of both isotherms is discussed. We also performed history matching with one production well from the Marcellus Shale and evaluated the contribution of gas desorption to the well's performance. History matching shows that gas adsorption obeying the BET isotherm contributes more to overall gas recovery than gas adsorption obeying the Langmuir isotherm, especially at early time in production. This work provides better understanding of gas desorption in shale-gas reservoirs and updates our current analytical and numerical models for simulation of shale-gas production.

Experimental Study on Gas Pressure Effects on Gas Desorption Characteristic of Coal Seam

2013 ◽  
Vol 318 ◽  
pp. 367-370 ◽  
Author(s):  
Lin Chao Dai ◽  
Da Yong Lu ◽  
Zhen Liu
Keyword(s):  
Coal Seam ◽  
Gas Adsorption ◽  
Experimental System ◽  
Gas Pressure ◽  
Pressure Effects ◽  
Gas Content ◽  
Equilibrium Pressure ◽  
Gas Desorption ◽  
Exploitation And Utilization ◽  
The Impact

To further explore the impact of gas pressure on gas desorption and flowing law, the gas desorption experimental system designed autonomously is used to carry out studies on gas desorption experiment under different gas pressures. By data fitting, the relationship between gas desorption quantity and time is obtained and also established the model for gas desorption. The results show that: the gas desorption quantity curves is "The first half rises sharply, the latter half segment is gently rising and eventually becomes stabilized", and when the gas adsorption equilibrium pressure is the greater, the gas desorption amount is greater. And the formula can describe the gas desorption law well, the correlation coefficient R2 is above 0.97. The study provides an important theory reference to coal and gas outburst prediction, coal seam gas content prediction and its exploitation and utilization.

Coal characterization and coalbed methane potential of the Chico-Lomã Coalfield, Paraná Basin, Brazil – Results from exploration borehole CBM001-CL-RS

2020 ◽  
Vol 38 (5) ◽  
pp. 1589-1630
Author(s):  
W Kalkreuth ◽  
J Levandowski ◽  
P Weniger ◽  
B Krooss ◽  
R Prissang ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Proximate Analysis ◽  
Methane Adsorption ◽  
Coal Seams ◽  
Gas Desorption ◽  
Coal Characterization ◽  
Thermal Origin ◽  
Methane Potential ◽  
Gas Volume ◽  
Hydrocarbon Distribution

The aim of this study was to determine the coal characteristics in the Chico-Lomã coalfield, Brazil and to evaluate the potential of natural gas associated with the coal seams (CBM), by carrying out a test well (CBM001-CL-RS) for collecting coal samples, followed by gas desorption measurements, and petrographical and chemical analyses of the coals and their methane adsorption capacities. The gas collected was analyzed for gas composition, stable carbon and hydrogen isotopes. The results indicate a cumulative coal thickness of 11.46 m in well CBM001-CL-RS, associated with an igneous intrusion of 10 m thickness. In the contact zone with the intrusion, the organic matter is severely altered with partial transformation of the coal to natural coke at distances less than 2 m from the intrusion. The ash content, based on proximate analysis, shows a variation from 29.1 to 82.8 wt.%. The sulphur content ranges from 0.43 to 3.89 wt.% and shows higher values in samples from the top of the Rio Bonito Formation. The gas desorption measurements range from 0.05 to 0.74 cm3/g, with methane being the predominant gas (>90%). A thermal origin of the gas is suggested by C and H isotopes and the C1 (methane) to C3 (propane) hydrocarbon distribution. The methane adsorption capacity of the samples varies from 2.50 to 6.50 cm3/g. Changes in microporosity related to thermal alteration may have a significant impact on the gas-holding capacity of samples located near the contact to the intrusion. For the study area, a 3D geological model was generated to estimate the volume of coal in the coalfield, followed by assessment of the gas volume associated with the coal. Based on the 3D model, a preliminary appraisal indicates resources of 7.2 billion tons of coal for the Chico-Lomã coalfield, associated with 2.7 billion m3 of gas.

scholarly journals Experimental Study of the Characteristic Changes of Coal Resistivity during the Gas Adsorption/Desorption Process

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Zengchao Feng ◽  
Chen Wang ◽  
Dong Dong ◽  
Dong Zhao ◽  
Dong Zhou
Keyword(s):  
Gas Adsorption ◽  
Gas Content ◽  
Resistivity Change ◽  
Adsorption Experiment ◽  
Desorption Process ◽  
Continuous Adsorption ◽  
Gas Desorption ◽  
Original Figure ◽  
Adsorption Desorption ◽  
The Relationship

To study the influence of gas adsorption-desorption on the resistivity of coal, the resistivity changes in conditions of continuous adsorption/desorption and isovolumetric adsorption/desorption were tested by high-precision resistance measurement, and the relationship between coal resistivity and gas content was investigated. The results show that gas adsorption/desorption has obvious effects on the resistivity of coal. Similar behavior was observed both in continuous adsorption/desorption and in isovolumetric adsorption/desorption experiments. The coal resistivity decreased gradually at the very beginning and then tended to stabilize as the gas adsorption capacity increased; in the process of gas desorption, the resistivity demonstrated a linear relationship with gas content. When comparing resistivities for the different adsorption modes, it was found that, for the same gas content in each mode, the resistivity change in the isovolumetric adsorption experiment was more obvious than in the continuous adsorption experiment. Also, the coal resistivity in the isovolumetric experiment differed further from the original figure when the desorption ended. The results are significant for predicting gas content in the coal mining process.

COAL SEAM GAS IN THE SOUTHERN SYDNEY BASIN, NEW SOUTH WALES

1997 ◽  
Vol 37 (1) ◽  
pp. 415 ◽  
Author(s):  
M.M. Faiz ◽  
A.C. Hutton
Keyword(s):  
Coal Seam ◽  
New South ◽  
Geological Structure ◽  
Gas Content ◽  
Gas Composition ◽  
Late Permian ◽  
Coal Seams ◽  
Coal Seam Gas ◽  
South Wales ◽  
Coal Measures

The coal seam gas content of the Late Permian Illawarra Coal Measures ranges from Methane that occurs within the basin was mainly derived as a by-product of coalification. Most of the CO2 was derived from intermittent magmatic activity between the Triassic and the Tertiary. This gas has subsequently migrated, mainly in solution, towards structural highs and accumulated in anticlines and near sealed faults.The total desorbable gas content of the coal seams is mainly related to depth, gas composition and geological structure. At depths

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