scholarly journals Geochemical investigation of hydrocarbon generation potential of coal from Raniganj Basin, India

2021 ◽  
Vol 11 (10) ◽  
pp. 3627-3636
Author(s):  
D. S. Panwar ◽  
Ram Chandra Chaurasia ◽  
V. K. Saxena ◽  
A. K. Singh ◽  
Akanksha

AbstractMethane content in a coal seam is a necessary parameter for evaluating coal bed gas, and it poses an environmental risk to underground coal mining activities. Keeping in pace with comprehensive studies of coal bed gas, 12 coal samples were selected from the Sitarampur block of Raniganj Coalfield for analysis. The Petrographic examination illustrated that significant values of reactive macerals present in samples demonstrate that organic matter is dominated by the prominent source of aromatic hydrocarbons with a minor proportion of aliphatic hydrocarbon, which falls in the region of (Type III) kerogen, confirms the suitability for the potential of hydrocarbon generation. “A” factor (aliphatic/aromatic bands) and “C” factor (carbonyl/carboxyl bands) value concluded that the sample has the lowest aromaticity and the highest hydrocarbon-generating potential, which was also validated by the Van Krevelen diagram. The Van Krevelen diagram plots between the H/C and O/C ratio indicate that coal samples lie in the type III kerogen, and bituminous coal (gas prone zone) is present in the block, which is confirmed by the cross-plot between desorbed and total gas (cc/g). The in situ gas content values are high enough to produce methane from coal beds. The overall study concludes that the Sitarampur block from Raniganj Coalfield is suitable for hydrocarbon generation and extraction.

2021 ◽  
Author(s):  
Deepak Singh Panwar ◽  
Ram Chandra Chaurasia ◽  
V K Saxena ◽  
A K Singh ◽  
Akanksha .

Abstract Methane content in a coal seam is a necessary parameter for evaluating coal bed gas, and it is a threat to underground coal mining activities from environmental aspects. Keeping in pace with comprehensive studies of coal bed gas, the authors had selected 12 coal samples from the Sitarampur block of Raniganj Coalfield. The Petrographic examination illustrated that significant values of reactive macerals present in samples demonstrate that organic matter is dominated by kerogen Type III, making it suitable for hydrocarbon generation. “A” factor (aliphatic/aromatic bands) and “C” factor (carbonyl/carboxyl bands) value concluded that the sample has the lowest aromaticity and the highest hydrocarbon-generating potential, which also validated by the cross plot between atomic H/C and O/C. The plots between the H/C and O/C ratio in the Van Krevelen diagram indicate that the coal samples lie in the type III kerogen, and bituminous coal (gas prone zone) is present in the block, which confirmed by the cross plot between desorbed and total gas (cc/g). The in-situ gas content values are high enough to produce methane from coal beds. The overall study concludes that the Sitarampur block from Raniganj Coalfield is suitable for hydrocarbon generation and extraction.


2012 ◽  
Vol 260-261 ◽  
pp. 284-289
Author(s):  
Hai Yan Liu ◽  
Zeng Xue Li ◽  
Da Wei Lv ◽  
Dong Dong Wang ◽  
Wen Feng Ning

The mining area of Jibei is an important coal production base, which located at the northern of Jining coalfield in Shandong province. The coal beds have the wide range of distribution and thicker sedimentary thickness in Shanxi Formation. The influence of structural feature to control the gas bearing in 3 coal bed is the paper’s important content. Two conclusions can be drawn from this study. The one is that open faults in whole area facilitate gasgascoal bed gas emitted from coal bed. The other is that closed faults in the local areas hinder gas emitted from coal bed. So, the laws are that the coal bed gas content and emission quantity are generally low in the whole mining area, but higher in parts area, and there are the abnormal gas zones at the special locations, where closed faults location.


2019 ◽  
Vol 105 ◽  
pp. 01044 ◽  
Author(s):  
Vyacheslav Smirnov ◽  
Valery Dyrdin ◽  
Tatyana Kim ◽  
Andrey Manakov

A substantial fraction of methane in undisturbed coal beds is present in the condensed latent state, so that methane evolution from coal may be not always quantitatively predicted reliably. On the basis of experimental data, an equation expressing the amount of gas hydrate through the sorption capacity and actual humidity of coal is obtained. Analysis showed that the gradient of gas pressure in the marginal zone of a coal bed is linearly dependent on the saturation of the pore space with the hydrate. The high gradient of gas pressure and high gas content of coal beds along with local disruption of coal and re-distribution of rock pressure are the major factors causing instantaneous outbursts of coal and gas.


2021 ◽  
Author(s):  
Makpal Bektybayeva ◽  
Nurhat Mendybaev ◽  
Asfandiyar Bigeldiyev ◽  
Subhro Basu ◽  
Auez Abetov ◽  
...  

Abstract For accurate coal bed methane (CBM) reserves estimation, it is necessary to evaluate reservoir characteristics. We present a workflow for formation evaluation of coalbed-methane wells, by interpretation of a limited number of legacy logs, including data preprocessing, lithology identification, proximate analysis and estimation of gas content of coal beds. This workflow allowed the estimation of ash content from the available logs, including selective log (analogue of photoelectric absorption), which was recorded only on the territory of the former Soviet Union and never used for such calculations before. Even though the logs were recorded by old tools with low vertical resolution, we were able to identify heterogeneity of coal seams, using the principle of core ash content distribution. Integrated analysis of old core data and recent laboratory measurements of samples from coal pillars allowed to calculate proximate properties of the coal, which showed good match with observed data and could be considered as input parameters for property distribution in the geological model. Also, it is worth to mention that an advanced plug-in was deployed to perform calculation of proximate properties and gas content for all available options and to significantly reduce time for screening different algorithms and rapidly analyzing results.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2679
Author(s):  
Yuying Zhang ◽  
Shu Jiang ◽  
Zhiliang He ◽  
Yuchao Li ◽  
Dianshi Xiao ◽  
...  

In order to analyze the main factors controlling shale gas accumulation and to predict the potential zone for shale gas exploration, the heterogeneous characteristics of the source rock and reservoir of the Wufeng-Longmaxi Formation in Sichuan Basin were discussed in detail, based on the data of petrology, sedimentology, reservoir physical properties and gas content. On this basis, the effect of coupling between source rock and reservoir on shale gas generation and reservation has been analyzed. The Wufeng-Longmaxi Formation black shale in the Sichuan Basin has been divided into 5 types of lithofacies, i.e., carbonaceous siliceous shale, carbonaceous argillaceous shale, composite shale, silty shale, and argillaceous shale, and 4 types of sedimentary microfacies, i.e., carbonaceous siliceous deep shelf, carbonaceous argillaceous deep shelf, silty argillaceous shallow shelf, and argillaceous shallow shelf. The total organic carbon (TOC) content ranged from 0.5% to 6.0% (mean 2.54%), which gradually decreased vertically from the bottom to the top and was controlled by the oxygen content of the bottom water. Most of the organic matter was sapropel in a high-over thermal maturity. The shale reservoir of Wufeng-Longmaxi Formation was characterized by low porosity and low permeability. Pore types were mainly <10 nm organic pores, especially in the lower member of the Longmaxi Formation. The size of organic pores increased sharply in the upper member of the Longmaxi Formation. The volumes of methane adsorption were between 1.431 m3/t and 3.719 m3/t, and the total gas contents were between 0.44 m3/t and 5.19 m3/t, both of which gradually decreased from the bottom upwards. Shale with a high TOC content in the carbonaceous siliceous/argillaceous deep shelf is considered to have significant potential for hydrocarbon generation and storage capacity for gas preservation, providing favorable conditions of the source rock and reservoir for shale gas.


Geophysics ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. B77-B84 ◽  
Author(s):  
Brian A. Lipinski ◽  
James I. Sams ◽  
Bruce D. Smith ◽  
William Harbert

Production of methane from thick, extensive coal beds in the Powder River Basin of Wyoming has created water management issues. Since development began in 1997, more than 650 billion liters of water have been produced from approximately 22,000 wells. Infiltration impoundments are used widely to dispose of by-product water from coal bed natural gas (CBNG) production, but their hydrogeologic effects are poorly understood. Helicopter electromagnetic surveys (HEM) were completed in July 2003 and July 2004 to characterize the hydrogeology of an alluvial aquifer along the Powder River. The aquifer is receiving CBNG produced water discharge from infiltration impoundments. HEM data were subjected to Occam’s inversion algorithms to determine the aquifer bulk conductivity, which was then correlated towater salinity using site-specific sampling results. The HEM data provided high-resolution images of salinity levels in the aquifer, a result not attainable using traditional sampling methods. Interpretation of these images reveals clearly the produced water influence on aquifer water quality. Potential shortfalls to this method occur where there is no significant contrast in aquifer salinity and infiltrating produced water salinity and where there might be significant changes in aquifer lithology. Despite these limitations, airborne geophysical methods can provide a broadscale (watershed-scale) tool to evaluate CBNG water disposal, especially in areas where field-based investigations are logistically prohibitive. This research has implications for design and location strategies of future CBNG water surface disposal facilities within the Powder River Basin.


2003 ◽  
Vol 14 (1) ◽  
pp. 59-67
Author(s):  
Adepo Jepson Olumide ◽  
Ayodele Charles Oludare ◽  
Balogun Olufemi

Coal, a solid fuel in its natural state has been identified as one of the world's major fossil fuels. It is a compact, stratified mass of mummified plant debris interspersed with smaller amounts of inorganic matter buried in sedimentary rocks. The use of coal as an energy source can be dated back to the prehistoric times. Methane is associated with many if not all coal seams, and is the dreaded “fire damp” responsible for many pit explosions. Coal mines are designed to vent as much methane as possible. It is present in the pores of coal under pressure, released during mining operations and can be extracted through vertical well bores. This paper highlights the fact that pipeline- quality methane can be extracted economically from coal seems before and during underground mining operations. The stimulation method involves hydraulic fracturing of the coal seam by using water, sand and, a gelling agent in a staged and alternating sand/and no sand sequence. The purpose is to create new fractures in the coal seam(s). The cleating of the coal helps to determine the flow characteristics of the coal formation and is vital in the initial productivity of a coal-methane well. The simple calculation of gas-in-place is achieved by multiplying the gas content of the coal by net coal thickness, the density, and the aerial extent of the drainage. The method is claimed to be suitable for use in Nigeria and potential sites for coal bed methane extraction in Nigeria are identified.


Georesursy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 21-33
Author(s):  
Vagif Kerimov ◽  
Nurdin Yandarbiev ◽  
Rustam Mustaev ◽  
Andrey Kudryashov

The article is devoted to the generation and accumulation systems in the territory of the Crimean-Caucasian segment of the Alpine folded system. An area of prolonged and stable sagging in the Mesozoic and Cenozoic – the Azov-Kuban Trough, which is a typical foreland basin – is distinguished within this segment. According to the results of geological and geochemical studies and modelling, depocentres are identified in this area, consolisated in four generative and accumulative hydrocarbon systems: Triassic-Jurassic, Cretaceous, Eocene and Maikop. Chemical-bitumenological, pyrolytic and coal petrology analysis of rock samples were carried out to assess geochemical conditions of oil and gas content in Meso-Cenozoic sediments. The modelling results made it possible to study and model the elements and processes of hydrocarbon systems in the Meso-Cenozoic in the Western Crimean-Caucasian region. It has been established that the extended catagenetic zoning is typical for these areas, which is caused by high rates of sedimentation and sagging, and large thicknesses of oil-bearing sediments in the source of oil formation, accordingly. The degree of organic matter depletion characterized the residual potential of the oil and gas source strata, was investigated. It is important for predicting and assessing the possibility of hydrocarbon generation.


The Rock–Eval pyrolysis and LECO analysis for 9 shale and 12 coal samples, as well as, geostatistical analysis have been used to investigate source rock characteristics, correlation between the assessed parameters (QI, BI, S1, S2, S3, HI, S1 + S2, OI, PI, TOC) and the impact of changes in the Tmax on the assessed parameters in the Cretaceous Sokoto, Anambra Basins and Middle Benue Trough of northwestern, southeastern and northcentral Nigeria respectively. The geochemical results point that about 97% of the samples have TOC values greater than the minimum limit value (0.5 wt %) required to induce hydrocarbon generation from source rocks. Meanwhile, the Dukamaje and Taloka shales and Lafia/Obi coal are found to be fair to good source rock for oil generation with slightly higher thermal maturation. The source rocks are generally immature through sub-mature to marginal mature with respect to the oil and gas window, while the potential source rocks from the Anambra Basin are generally sub-mature grading to mature within the oil window. The analyzed data were approached statistically to find some relations such as factors, and clusters concerning the examination of the source rocks. These factors were categorized into type of organic matter and organic richness, thermal maturity and hydrocarbon potency. In addendum, cluster analysis separated the source rocks in the study area into two groups. The source rocks characterized by HI >240 (mg/g), TOC from 58.89 to 66.43 wt %, S1 from 2.01 to 2.54 (mg/g) and S2 from 148.94 to 162.52 (mg/g) indicating good to excellent source rocks with kerogen of type II and type III and are capable of generating oil and gas. Followed by the Source rocks characterized by HI <240 (mg/g), TOC from 0.94 to 36.12 wt%, S1 from 0.14 to 0.72 (mg/g) and S2 from 0.14 to 20.38 (mg/g) indicating poor to good source rocks with kerogen of type III and are capable of generating gas. Howeverr, Pearson’s correlation coefficient and linear regression analysis shows a significant positive correlation between TOC and S1, S2 and HI and no correlation between TOC and Tmax, highly negative correlation between TOC and OI and no correlation between Tmax and HI. Keywords- Cretaceous, Geochemical, Statistical, Cluster; Factor analyses.


2018 ◽  
Vol 36 (5) ◽  
pp. 1157-1171
Author(s):  
Agostinho Mussa ◽  
Deolinda Flores ◽  
Joana Ribeiro ◽  
Ana MP Mizusaki ◽  
Mónica Chamussa ◽  
...  

The Mozambique Basin, which occurs onshore and offshore in the central and southern parts of Mozambique, contains a thick sequence of volcanic and sedimentary rocks that range in age from the Jurassic to Cenozoic. This basin, along with the Rovuma basin to the north, has been the main target for hydrocarbon exploration; however, published data on hydrocarbon occurrences do not exist. In this context, the present study aims to contribute to the understanding of the nature of the organic matter of a sedimentary sequence intercepted by the Nemo-1X exploration well located in the offshore area of the Mozambique Basin. The well reached a depth of 4127 m, and 33 samples were collected from a depth of 2219–3676 m ranging in age from early to Late Cretaceous. In this study, petrographic and geochemical analytical methods were applied to assess the level of vitrinite reflectance and the organic matter type as well as the total organic carbon, total sulfur, and CaCO3 contents. The results show that the total organic carbon content ranges from 0.41 to 1.34 wt%, with the highest values determined in the samples from the Lower Domo Shale and Sena Formations, which may be related to the presence of the solid bitumens that occur in the carbonate fraction of those samples. The vitrinite random reflectances range from 0.65 to 0.86%Rrandom, suggesting that the organic matter in all of the samples is in the peak phase of the “oil generation window” (0.65–0.9%Rrandom). The organic matter is mainly composed of vitrinite and inertinite macerals, with a minor contribution of sporinite from the liptinite group, which is typical of kerogen type III. Although all of the samples have vitrinite reflectances corresponding to the oil window, the formation of liquid hydrocarbons is rather limited because the organic matter is dominated by gas-prone kerogen type III.


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