K. Pinetown - Academia.edu (original) (raw)
Papers by K. Pinetown
Energy Procedia, 2011
ABSTRACT Clastic sedimentary rocks associated with coal seams affect the retention of gas and the... more ABSTRACT Clastic sedimentary rocks associated with coal seams affect the retention of gas and the rate of escape of CO2 and CH4 from a coal seam gas (CSG) system. Quantifying sealing properties using a parameter based on molecular diffusion and permeation of gases through rock and coal matrices allows the effects to be evaluated.Observations made on a CSG system in the Hunter Coalfield, Sydney Basin, Australia, show that the gas contents vary between ∼0.5 m3/t and ∼10 m3/t. The CSG consists predominantly (>80%) of CH4. Analyses of stable carbon isotopes indicate that the CH4 is mainly biogenic, with gases in deeper seams showing mixing with thermogenic sources. At depths less than about 500 m, the coal seams containing elevated gas contents are generally overlain by low permeability, fine-grained clastic rocks such as mudstone and carbonaceous shale.Using a purpose-built system to measure matrix permeability and diffusivity of a coal and its roof and floor rocks allows characterisation of long-term permeation and diffusive flow. Measurements indicate that permeation and diffusion take place at different rates depending on gas type. A main finding of the study is that CH4 permeates more rapidly than CO2 whereas CO2 diffuses more rapidly than CH4. For the studied samples, gas diffusion in coal is slower than in the clastic rocks, indicating that the minor coal seams are even better seals compared to the interseam clastic rocks for the main coal seam reservoir.Differences in flow regimes vary with lithology and therefore differences in lithology affect the retention of CO2 versus CH4. For example, the permeation of both CO2 and CH4 is several times more rapid in the sandstone than for the claystone analysed, but diffusive flow is similar for these two samples.Carrying out analyses such as those done in the present study will assist in evaluating gas containment properties of interseam strata in CSG systems over given periods of time. Quantification of these properties will assist in evaluating the potential for CO2 injection and long-term storage in coal seams.
Australian Journal of Earth Sciences, 2014
... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Not... more ... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Notes - Geological Survey of New South Wales (16) The APEA Journal (14) Annual Meeting Expanded Abstracts - American Association ...
International Journal of Coal Geology, 2008
... explosions are not uncommon events. Gouws and Knoetze (1995) discuss coal self-heating and ex... more ... explosions are not uncommon events. Gouws and Knoetze (1995) discuss coal self-heating and explosibility as elements of research programmes undertaken by various research organisations in South Africa. For the period of ...
International Journal of Coal Geology, 2007
This study has investigated the quantitative distribution of minerals in coals and other litholog... more This study has investigated the quantitative distribution of minerals in coals and other lithological units in the coal-bearing successions of the Witbank and Highveld Coalfields in the Mpumalanga Province of South Africa, using low-temperature oxygenplasma ashing (LTA), high temperature ashing, X-ray diffraction, and X-ray fluorescence spectrometry techniques. Mineral matter makes up approximately 8 to 35 wt.% of the coal samples. SiO 2 concentrations in the coal vary between 0.0 and 35.0 wt.%, Al 2 O 3 between 0.5 and 16.0 wt.%, Fe 2 O 3 between 0.03 and 10.0 wt.%, and S between 0.15 and 8.0 wt.%. Minor concentrations of CaO (0.0 to 8.0 wt.%) and MgO (0.0 to 1.0 wt.%) are also present. P 2 O 5 occurs in concentrations of 0.0 to 3.5 wt.% and K 2 O is in the order of 0.0 to 1.3 wt.%. Na 2 O varies between 0.0 and 0.45 wt.%, with the Highveld coals showing an enrichment in Na 2 O (0.0 to 0.51 wt.%) in comparison with the Witbank coals. The minerals in the coals are dominated by quartz and kaolinite, with varying proportions of calcite, dolomite and pyrite, as well as accessory phosphate phases. Higher (normalised) K 2 O and Na 2 O concentrations are present in the sandstones than in the associated siltstones and carbonaceous shales, partly reflecting the presence of feldspars and clay minerals such as illite.
Geofluids, 2014
ABSTRACT To quantify and rank gas wettability of coal as a key parameter affecting the extent of ... more ABSTRACT To quantify and rank gas wettability of coal as a key parameter affecting the extent of CO2 sequestration in coal and CH4 recovery from coal, we developed a contact angle measuring system based on a captive gas bubble technique. We used this system to study the gas wetting properties of an Australian coal from the Sydney Basin. Gas bubbles were generated and captivated beneath a coal sample within a distilled water-filled (pH 5.7) pressurised cell. Because of the use of distilled water, and the continuous dissolution and shrinkage of the gas bubble in water during measurement, the contact angles measured correspond to a ‘transient receding’ contact angle. To take into account the mixed-gas nature (CO2, CH4, and to a lesser extent N2) of coal seam gas in the basin, we evaluated the relative wettability of coal by CH4, CO2 and N2 gases in the presence of water. Measurements were taken at various pressures of up to 15 MPa for CH4 and N2, and up to 6 MPa for CO2 at a constant temperature of 22°C. Overall, our results show that CO2 wets coal more extensively than CH4, which in turn wets coal slightly more than N2. Moreover, the contact angle reduces as the pressure increases, and becomes < 90° at various pressures depending on the gas type. In other words, all three gases wet coal better than water under sufficiently high pressure.
... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Not... more ... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Notes - Geological Survey of New South Wales (16) The APEA Journal (14) Annual Meeting Expanded Abstracts - American Association ...
Energy Procedia, 2011
ABSTRACT Clastic sedimentary rocks associated with coal seams affect the retention of gas and the... more ABSTRACT Clastic sedimentary rocks associated with coal seams affect the retention of gas and the rate of escape of CO2 and CH4 from a coal seam gas (CSG) system. Quantifying sealing properties using a parameter based on molecular diffusion and permeation of gases through rock and coal matrices allows the effects to be evaluated.Observations made on a CSG system in the Hunter Coalfield, Sydney Basin, Australia, show that the gas contents vary between ∼0.5 m3/t and ∼10 m3/t. The CSG consists predominantly (>80%) of CH4. Analyses of stable carbon isotopes indicate that the CH4 is mainly biogenic, with gases in deeper seams showing mixing with thermogenic sources. At depths less than about 500 m, the coal seams containing elevated gas contents are generally overlain by low permeability, fine-grained clastic rocks such as mudstone and carbonaceous shale.Using a purpose-built system to measure matrix permeability and diffusivity of a coal and its roof and floor rocks allows characterisation of long-term permeation and diffusive flow. Measurements indicate that permeation and diffusion take place at different rates depending on gas type. A main finding of the study is that CH4 permeates more rapidly than CO2 whereas CO2 diffuses more rapidly than CH4. For the studied samples, gas diffusion in coal is slower than in the clastic rocks, indicating that the minor coal seams are even better seals compared to the interseam clastic rocks for the main coal seam reservoir.Differences in flow regimes vary with lithology and therefore differences in lithology affect the retention of CO2 versus CH4. For example, the permeation of both CO2 and CH4 is several times more rapid in the sandstone than for the claystone analysed, but diffusive flow is similar for these two samples.Carrying out analyses such as those done in the present study will assist in evaluating gas containment properties of interseam strata in CSG systems over given periods of time. Quantification of these properties will assist in evaluating the potential for CO2 injection and long-term storage in coal seams.
Australian Journal of Earth Sciences, 2014
... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Not... more ... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Notes - Geological Survey of New South Wales (16) The APEA Journal (14) Annual Meeting Expanded Abstracts - American Association ...
International Journal of Coal Geology, 2008
... explosions are not uncommon events. Gouws and Knoetze (1995) discuss coal self-heating and ex... more ... explosions are not uncommon events. Gouws and Knoetze (1995) discuss coal self-heating and explosibility as elements of research programmes undertaken by various research organisations in South Africa. For the period of ...
International Journal of Coal Geology, 2007
This study has investigated the quantitative distribution of minerals in coals and other litholog... more This study has investigated the quantitative distribution of minerals in coals and other lithological units in the coal-bearing successions of the Witbank and Highveld Coalfields in the Mpumalanga Province of South Africa, using low-temperature oxygenplasma ashing (LTA), high temperature ashing, X-ray diffraction, and X-ray fluorescence spectrometry techniques. Mineral matter makes up approximately 8 to 35 wt.% of the coal samples. SiO 2 concentrations in the coal vary between 0.0 and 35.0 wt.%, Al 2 O 3 between 0.5 and 16.0 wt.%, Fe 2 O 3 between 0.03 and 10.0 wt.%, and S between 0.15 and 8.0 wt.%. Minor concentrations of CaO (0.0 to 8.0 wt.%) and MgO (0.0 to 1.0 wt.%) are also present. P 2 O 5 occurs in concentrations of 0.0 to 3.5 wt.% and K 2 O is in the order of 0.0 to 1.3 wt.%. Na 2 O varies between 0.0 and 0.45 wt.%, with the Highveld coals showing an enrichment in Na 2 O (0.0 to 0.51 wt.%) in comparison with the Witbank coals. The minerals in the coals are dominated by quartz and kaolinite, with varying proportions of calcite, dolomite and pyrite, as well as accessory phosphate phases. Higher (normalised) K 2 O and Na 2 O concentrations are present in the sandstones than in the associated siltstones and carbonaceous shales, partly reflecting the presence of feldspars and clay minerals such as illite.
Geofluids, 2014
ABSTRACT To quantify and rank gas wettability of coal as a key parameter affecting the extent of ... more ABSTRACT To quantify and rank gas wettability of coal as a key parameter affecting the extent of CO2 sequestration in coal and CH4 recovery from coal, we developed a contact angle measuring system based on a captive gas bubble technique. We used this system to study the gas wetting properties of an Australian coal from the Sydney Basin. Gas bubbles were generated and captivated beneath a coal sample within a distilled water-filled (pH 5.7) pressurised cell. Because of the use of distilled water, and the continuous dissolution and shrinkage of the gas bubble in water during measurement, the contact angles measured correspond to a ‘transient receding’ contact angle. To take into account the mixed-gas nature (CO2, CH4, and to a lesser extent N2) of coal seam gas in the basin, we evaluated the relative wettability of coal by CH4, CO2 and N2 gases in the presence of water. Measurements were taken at various pressures of up to 15 MPa for CH4 and N2, and up to 6 MPa for CO2 at a constant temperature of 22°C. Overall, our results show that CO2 wets coal more extensively than CH4, which in turn wets coal slightly more than N2. Moreover, the contact angle reduces as the pressure increases, and becomes < 90° at various pressures depending on the gas type. In other words, all three gases wet coal better than water under sufficiently high pressure.
... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Not... more ... Society of America (20) Geochimica et Cosmochimica Acta (18) AAPG Bulletin (17) Quarterly Notes - Geological Survey of New South Wales (16) The APEA Journal (14) Annual Meeting Expanded Abstracts - American Association ...