METHANE DRAINAGE POTENTIAL OF THE NORTHERN BOWEN BASIN

1987 ◽  
Vol 27 (1) ◽  
pp. 281 ◽  
Author(s):  
R. M. Bell
Keyword(s):  
Physical Parameters ◽  
Transport Costs ◽  
Coal Seams ◽  
Commercial Development ◽  
Methane Drainage ◽  
Reducing Gas ◽  
Considerable Research ◽  
Differential Flow ◽  
Area North ◽  
Coal Measures

Large volumes of methane plus some other gases are generated during the coalification process. Under suitable conditions some of this gas is adsorbed within the microporosity of coals. The rate at which the gas can desorb is a function of the permeability, degree of fracturing or cleating, moisture content, geochemistry of the coals, and the pressure differential. Flow rates from coals are generally low but can be dramatically improved by artificial stimulation and techniques such as lateral drilling.Methane drainage or coal de-methanisation has been carried out for many years, primarily for safety reasons. The resource value of methane in coal seams is now being recognised and considerable research is being undertaken both overseas and in Australia.In the Northern Bowen Basin, several million tonnes of coal are mined each year. The main seams of the Permian Collinsville, Moranbah, German Creek, and Rangal Coal Measures are generally thick and laterally extensive. The area north of Blackwater probably contains more than 100 billion tonnes of coal from which several hundred billion m3 (several Bcf) methane could conceivably be recovered in those areas where the coals are too deep for commercial exploitation.The coals of the Northern Bowen Basin are considered to have better physical parameters for the commercial development of methane drainage projects than those of the central and southern Bowen Basin where methane drainage projects were undertaken several years ago. It is estimated that more than 85 million m3 (3 Bcf) of recoverable gas per square km could be present in some areas. This gas can probably be produced for less than $1.50/GJ (1 Mcft, a figure which compares favourably with many conventional natural gas sources.The Northern Bowen Basin is well-situated with respect to potential gas markets at Townsville and Gladstone. The gas could also be used as a chemical feedstock for products such as ammonia, fertilisers, explosives or synfuels, with the plants located close to the producing wells, thus significantly reducing gas transport costs.

COALBED METHANE RESOURCES IN THE PERMIAN OF EASTERN AUSTRALIA AND THEIR TECTONIC SETTING

1993 ◽  
Vol 33 (1) ◽  
pp. 161 ◽  
Author(s):  
S. Miyazaki ◽  
R.J. Korsch
Keyword(s):  
Coalbed Methane ◽  
Tectonic Setting ◽  
Temporal Distribution ◽  
Low Permeability ◽  
Burial History ◽  
Coal Seams ◽  
Methane Drainage ◽  
Eastern Australia ◽  
Permian Coal ◽  
Coal Measures

The Bowen and Sydney Basins in eastern Australia contain vast coal resources which provide a source for coalbed methane. Through studies of the spatial and temporal distribution of the sedimentary packages, the structural geometry and tectonic setting of the sedimentary packages, and the maturation and burial history, the Australian Geological Survey Organisation (AGSO) is mapping the distribution and structural styles of the sources of methane, in particular, the Late Permian coal measures. AGSO's results from the Bowen Basin show at least two distinctly different structural styles of potential targets for coalbed methane drainage: on the Comet Ridge, the Permian coal measures are essentially subhorizontal and tectonically undisturbed, whereas in the western Taroom Trough, the coal measures are folded into a series of anticlines, each of which occurs above a thrust fault which in turn forms part of an imbricate thrust fan. Both of these styles occur at depths of less than 1000 m.Calculations by the Bureau of Resource Sciences (BRS) indicate that the inferred coalbed methane resources-in-place are 62 trillion cubic feet (1760 billion m3) for Australia, in which the Bowen and Sydney Basins are currently the only potential provinces of coalbed methane. The low permeability of the coal seams hinders attempts to utilise this vast amount of energy resources.Further exploration is necessary to delineate commercially feasible areas. This delineation is the only process that will be able to determine demonstrated coalbed methane resources.

scholarly journals The Impact of the Coexistence of Methane Hazard and Rock-Bursts on the Safety of Works in Underground Hard Coal Mines

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 128
Author(s):  
Justyna Swolkień ◽  
Nikodem Szlązak
Keyword(s):  
Rock Burst ◽  
Methane Concentration ◽  
High Energy ◽  
Hard Coal ◽  
Coal Seams ◽  
Safety Level ◽  
Methane Drainage ◽  
Innovative Methods ◽  
Hard Coal Mining ◽  
The Impact

Several natural threats characterize hard coal mining in Poland. The coexistence of methane and rock-burst hazards lowers the safety level during exploration. The most dangerous are high-energy bumps, which might cause rock-burst. Additionally, created during exploitation, safety pillars, which protect openings, might be the reason for the formation of so-called gas traps. In this part, rock mass is usually not disturbed and methane in seams that form the safety pillars is not dangerous as long as they remain intact. Nevertheless, during a rock-burst, a sudden methane outflow can occur. Preventing the existing hazards increases mining costs, and employing inadequate measures threatens the employees’ lives and limbs. Using two longwalls as examples, the authors discuss the consequences of the two natural hazards’ coexistence. In the area of longwall H-4 in seam 409/4, a rock-burst caused a release of approximately 545,000 cubic meters of methane into the excavations, which tripled methane concentration compared to the values from the period preceding the burst. In the second longwall (IV in seam 703/1), a bump was followed by a rock-burst, which reduced the amount of air flowing through the excavation by 30 percent compared to the airflow before, and methane release rose by 60 percent. The analyses presented in this article justify that research is needed to create and implement innovative methods of methane drainage from coal seams to capture methane more effectively at the stage of mining.

Optimization of Coal Seam Connectivity via Multi-Seam Pinpoint Fracturing Operations in the Walloons Coal Measures, Surat Basin

2021 ◽  
Author(s):  
Vibhas J. Pandey ◽  
Sameer Ganpule ◽  
Steven Dewar
Keyword(s):  
Coal Seam ◽  
History Matching ◽  
Design Matrix ◽  
Coal Seams ◽  
Major Step ◽  
Well Completion ◽  
Eastern Australia ◽  
Treatment Designs ◽  
Coal Measures ◽  
Gas Bearing

Abstract The Walloons coal measures located in Surat Basin (eastern Australia) is a well-known coal seam gas play that has been under production for several years. The well completion in this play is primarily driven by coal permeability which varies from 1 Darcy or more in regions with significant natural fractures to less than 1md in areas with underdeveloped cleat networks. For an economic development of the latter, fracturing treatment designs that effectively stimulate numerous and often thin coals seams, and enhance inter-seam connectivity, are a clear choice. Fracture stimulation of Surat basin coals however has its own challenges given their unique geologic and geomechanical features that include (a) low net to gross ratio of ~0.1 in nearly 300 m (984.3 ft) of gross interval, (b) on average 60 seams per well ranging from 0.4 m to 3 m in thickness, (c) non-gas bearing and reactive interburden, and (d) stress regimes that vary as a function of depth. To address these challenges, low rate, low viscosity, and high proppant concentration coiled tubing (CT) conveyed pinpoint stimulation methods were introduced basin-wide after successful technology pilots in 2015 (Pandey and Flottmann 2015). This novel stimulation technique led to noticeable improvements in the well performance, but also highlighted the areas that could be improved – especially stage spacing and standoff, perforation strategy, and number of stages, all aimed at maximizing coal coverage during well stimulation. This paper summarizes the findings from a 6-well multi-stage stimulation pilot aimed at studying fracture geometries to improve standoff efficiency and maximizing coal connectivity amongst various coal seams of Walloons coal package. In the design matrix that targeted shallow (300 to 600 m) gas-bearing coal seams, the stimulation treatments varied in volume, injection rate, proppant concentration, fluid type, perforation spacing, and standoff between adjacent stages. Treatment designs were simulated using a field-data calibrated, log-based stress model. After necessary adjustments in the field, the treatments were pumped down the CT at injection rates ranging from 12 to 16 bbl/min (0.032 to 0.042 m3/s). Post-stimulation modeling and history-matching using numerical simulators showed the dependence of fracture growth not only on pumping parameters, but also on depth. Shallower stages showed a strong propensity of limited growth which was corroborated by additional field measurements and previous work in the field (Kirk-Burnnand et al. 2015). These and other such observations led to revision of early guidelines on standoff and was considered a major step that now enabled a cost-effective inclusion of additional coal seams in the stimulation program. The learnings from the pilot study were implemented on development wells and can potentially also serve as a template for similar pinpoint completions worldwide.

scholarly journals Analysis of methane hazard in longwall working equipped with a powered longwall complex

2020 ◽  
Vol 174 ◽  
pp. 01011
Author(s):  
Leszek Sobik ◽  
Jarosław Brodny ◽  
Gennady Buyаlich ◽  
Pavel Strelnikov
Keyword(s):  
High Performance ◽  
Underground Mining ◽  
Practical Knowledge ◽  
Mining Operation ◽  
Mining Area ◽  
Hard Coal ◽  
Coal Seams ◽  
Methane Drainage ◽  
High Degree ◽  
Advanced Model

Most of currently exploited hard coal seams has a very high degree of methane saturation. Consequently, the mining process of such deposits generates substantial amounts of methane. This in turn increases the risk of fire and/or explosion of this gas. Methane hazard is currently one of the most dangerous threats occurring in the process of underground mining exploitation. In particular, this applies to longwall excavations where the rock mass mining process generates the highest level of this gas. Commonly used high-performance longwall complexes cause an increase in the amount of coal output, which also causes an increase in the amount of methane released. In order to prevent hazardous concentrations, appropriate ventilation systems and atmosphere monitoring in mining excavations are used. The paper discusses currently used methods designed to limit risks caused by methane such as methane drainage. The paper presents an example of the use of an innovative method of analysing methane risk status and measures aimed at minimizing it. The developed method is based on air parameters in the actual mining area which were then used to create a method of ventilation for such excavations. The method combines advanced model analysis and experience of mine employees and integrates academic and practical knowledge. The main objective of the activities presented in the article was to improve the safety of mining operation

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.

Hilt's Law and the Volatile Contents of Coal Seams

1949 ◽  
Vol 86 (5) ◽  
pp. 303-312 ◽  
Author(s):  
O. T. Jones
Keyword(s):  
High Pressures ◽  
Volatile Matter ◽  
Physical Factors ◽  
Recent Theory ◽  
Coal Seams ◽  
South Wales ◽  
Coal Measures ◽  
Depth Of Burial

AbstractDr. Trotter's recent theory of devolatilization of coal seams is criticized on structural grounds and the “square law” suggested is shown to be no improvement on many other expressions of varied types. The data are best represented both for South Wales and the Kent Coalfield by Hilt's law. The influence of depth of burial on coal vegetation is discussed; loss of volatile matter is probably promoted by temperatures, but is almost certainly retarded by high pressures. The Hilt rate is controlled by the chemical-physical factors and may be influenced also by varying rates of sedimentation during the accumulation of the Coal Measures.

The Faunal Sequence in the Kent Coalfield

1946 ◽  
Vol 83 (6) ◽  
pp. 266-279 ◽  
Author(s):  
C. J. Stubblefield ◽  
A. E. Trueman
Keyword(s):  
Fossil Flora ◽  
Coal Seams ◽  
Coal Measures ◽  
Dividing Line

A Summary of the stratigraphy of the Coal Measures in the Kent Coalfield was given by H. G. Dines in 1933, accompanied by notes on the fossil flora by R. Crookall and on the fauna by C. J. Stubblefield. It was shown that the Coal Measures could be divided into a Lower or Shale Division, some 700 feet thick, consisting mainly of shales with some thick coals, and an Upper or Sandstone Division, about 2,100 feet thick, consisting mainly of sandstone with a few mostly impersistent coal seams, except in the highest part where again there are shales with coals (Dines, 1933, p. 22); the dividing line was taken at the base of a sandstone usually about 100 feet below the Millyard Seam. Recently the correlatable seams in the coalfield have been designated by means of numbers in downward succession and seams numbered 1–6 lie in the Sandstone Division, and numbers 7–14 in the Shale Division (Dines, 1945). R. Crookall regarded the Upper or Sandstone Division as representing the StafFordian and part of the Radstockian series, while the Shale Division he referred to the Yorkian (Text-fig. 1).

scholarly journals Stratigraphic ranges of selected miospores in coal seams of Upper Coal Measures age in Oxfordshire and S.E. Warwickshire

1987 ◽  
Vol 6 (1) ◽  
pp. 21-37 ◽  
Author(s):  
A. H. V. Smith
Keyword(s):  
New Species ◽  
Unique Sequence ◽  
Illinois Basin ◽  
Coal Seams ◽  
Two New Species ◽  
Assemblage Zone ◽  
Bituminous Coals ◽  
Stratigraphic Ranges ◽  
Coal Measures ◽  
Marker Comparison

Abstract. The extensive programme of boring recently undertaken by the National Coal Board to establish the limits of the concealed coalfield in Oxfordshire and southeast Warwickshire, has provided a unique sequence of high volatile bituminous coals from the upper part of the Upper Coal Measures suitable for spore analysis. The coals are mainly bright and the possible implications for the spore flora are briefly considered. The spores from the coals are characteristic of Westphalian D assemblages but the problem of recognising the base of the Westphalian D is discussed. It is concluded that the seams under investigation are all of Westphalian D age. Two new species, Vestispora burfordiensis and V. witneyensis are described. The occurrence of these species as well as Schopfites dimorphus and Punctatosporites granifer in Oxfordshire and in other British coalfields is reviewed. The ranges of these species provide the basis for recognising three new miospore assemblage zones to replace the former Thymospora obscura Assemblage Zone XI of Smith & Butterworth (1967). The base of the epibole of Thymospora pseudothiessenii is also well defined and is a useful biostratigraphic marker. Comparison is made with the zonal sub-division of the Desmoinesian series of the Illinois basin by Peppers (1985).

scholarly journals PEMETAAN TINGKAT PENCEMARAN AIR SUNGAI SIAK SEBELUM DAN SESUDAH MELALUI SISTEM FILTRASI DENGAN 2 KALI PENYARINGAN BERDASARKAN PARAMETER FISIS

2020 ◽  
Vol 3 (1) ◽  
pp. 15-20
Author(s):  
M. YANUAR PRASETYO ◽  
Riad Syech ◽  
Usman Malik
Keyword(s):  
River Water ◽  
Ph Value ◽  
Physical Parameters ◽  
Filtration Process ◽  
Filtration System ◽  
Measurement Results ◽  
Before And After ◽  
Slow Sand Filter ◽  
Sample Points ◽  
Area North

Abstrak Telah dilakukan pemetaan tingkat pencemaran air sungai siak sebelum dan sesudah melalui sistem filtrasi dengan 2 kali penyaringan berdasarkan parameter fisis. Pemetaan dilakukan berdasarkan nilai Konduktivitas, TDS, dan nilai pH dari sampel air yang diambil dibadan air sungai siak, baik sebelum dan setelah proses filtrasi menggunakan saringan pasir lambat yang dibuat dengan bahan utama pasir kuarsa, batu zeolit, batu bioring, arang, busa penyaring dan kerikil. Pengambilan sampel air dilakukan di atas permukaan air Sungai Siak pada 2 sisi sungai yaitu daerah sebelah Utara Sungai Siak di Kecamatan Rumbai Pesisir diambil sebanyak 15 titik sampel, dan sebelah Selatan Sungai Siak di Kecamatan Senapelan diambil sebanyak 15 titik sampel. Pengukuran dilakukan menggunakan konduktiviti meter, dan pH meter, sementara nilai TDS diperoleh melalui perhitungan menggunakan nilai konduktivitas. Hasil pengukuran 30 titik sampel sebelum proses filtrasi menunjukkan daerah B dengan nilai konduktivitas rata-rata 41,3µS/cm, dan nilai TDS rata-rata 26,45mg/L memiliki nilai yang lebih rendah dari daerah A yang memiliki nilai konduktivitas rata-rata 63,93µS/cm dan nilai TDS rata-rata 40,9mg/L. Setelah proses filtrasi dilakukan nilai konduktivitas rata-rata sampel daerah A naik menjadi 204,7µS/cm dan daerah B naik menjadi 156,3µS/cm, kenaikan yang sama terjadi untuk parameter TDS, dan pH. Peningkatan nilai konduktivitas, TDS, dan pH masih berada dibawah ambang batas sehingga sistem filtrasi dengan 2 kali penyaringan berhasil mengubah air Sungai Siak menjadi air bersih.  Abstract Mapping of the level of pollution of Siak river has been carried out before and after through the filtration system with 2 times of filtering based on physical parameters. Mapping is done based on the conductivity value, TDS, and pH value of water samples taken in the Siak river water, both before and after the filtration process using a slow sand filter made with the main ingredients of quartz sand, zeolite stones, bioring stones, charcoal, filter foam and gravel. Water sampling was carried out on the surface of the Siak River on 2 sides of the river: the area north of the Siak River in Rumbai Pesisir District was taken as many as 15 sample points, and south of the Siak River in Senapelan District was taken as many as 15 sample points. Measurements were made using conductivity meters and pH meters, while TDS values were obtained through calculations using conductivity values. The measurement results of 30 sample points before the filtration process showed area B with an average conductivity value of 41.3 µS / cm, and an average TDS value of 26.45 mg / L had a lower value than region A which had an average conductivity value of 63 , 93µS / cm and an average TDS value of 40.9 mg / L. After the filtration process the average conductivity value of the sample area A increased to 204.7 µS / cm and area B increased to 156.3 µS / cm, the same increase occurred for the TDS parameters, and pH. Increasing the conductivity, TDS, and pH values are still below the threshold so that the filtration system with 2 times of filtering succeeded in changing the Siak River water into clean water.

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