Coal microstructure and micropermeability and their effects on natural gas recovery

Gamson, Paul D.; Beamish, B. B.; Johnson, David P.

doi:10.1016/0016-2361(93)90381-b

Cited by 228 publications

(78 citation statements)

References 7 publications

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“…In USA (Fruitland Formation) the gas Table 17 Cleat classifications: parameters and systems (see Fig. 12; Ammosov and Eremin, 1963;Gamson et al, 1993) Remarks:…”

Section: The Gas Window and Cbm Resourcesmentioning

confidence: 99%

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

Alpern¹,

Sousa²

2002

International Journal of Coal Geology

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This paper deals with all solid sedimentary fossil fuels, i.e. coal, the main one for geological reserves and resources, peat, and oil shales. Definitions of coal ( < 50% ash) and coal seam (thickness and depth limits) are examined in view of an international agreement regarding new concepts for a common reserves and resources evaluation using the same nomenclature.The 50% ash limit, already adopted by UN-ECE for coal definition, allows the creation of a new category-the organic shales (50 -75% ash)-comprising energetic materials still valuable for thermal use (coal shales) or to be retorted for oil production (oil shales).Geological relations between coals, oil shales, solid bitumen, liquid hydrocarbons, natural gas, and coalbed methane are also examined together with environmental problems.As a final synthesis of all topics, the paper discusses the problems related with a modern geological classification of all solid sedimentary fuels based on: various rank parameters (moisture content, calorific value, reflectance), maceral composition, and mineral matter content (and washability).Finally, it should be pointed out that the paper is presented as series of problems, some of them old ones, but never resolved until now. In order to facilitate the next generation of coal geologists to resolve these problems on the basis of international agreements, all sections begin with documented introductions for further questions opening an international enquiry. The authors hope that the answers will be abundant enough and pertinent to permit synthetic international solutions, valuable for the new millennium, with the help of interested consulted authorities, international pertinent organisations, and regional experts. D

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“…In USA (Fruitland Formation) the gas Table 17 Cleat classifications: parameters and systems (see Fig. 12; Ammosov and Eremin, 1963;Gamson et al, 1993) Remarks:…”

Section: The Gas Window and Cbm Resourcesmentioning

confidence: 99%

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

Alpern¹,

Sousa²

2002

International Journal of Coal Geology

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“…An example of several small micro fractures is illustrated in Figure 2.5. Other studies that have examined non-stressed conditions detail larger aperture sizes ranging from 10-300 µm depending on basin and depth (Close and Mavor, 1991;Gamson and Beamish, 1991;Laubach et al, 1998). In their report on Western North China Coal, Su et al (2001) reported an unstressed aperture range from 1 µm to 8 mm.…”

Section: Dual Porosity Of Coalmentioning

confidence: 92%

“…Both the face and butt cleats propagate perpendicular fissures about the bedding plane. Face cleat are more prominent and continuous (Dawson and Esterle, 2010;Gamson et al, 1993;Laubach et al, 1998). The butt cleats tend to terminate once it intersects perpendicular to the face cleats and thus is the shortest of the pair (Kumar et al, 2011;Mavor and Gunter, 2006) and are assumed to have formed later (Mandal et al, 2004).…”

Section: Dual Porosity Of Coalmentioning

confidence: 99%

“…As such, variation between basins may be extensive. Spacing varies with coal rank to form a bell-shaped distribution curve, decreasing from lignite to medium volatile bituminous and increasing through the anthracite range (Gamson et al, 1993;Law, 1993;Mazumder et al, 2006); and is influenced by coal lithotype and ash yield (Law, 1993). Laubach et al (1998) stated that coal with high ash yield had a greater degree of cleat spacing compared to low ash yield.…”

Section: Dual Porosity Of Coalmentioning

confidence: 99%

“…Measuring contact angle on a rough surface and hysteresis Gamson et al (1993) reported that coal possessed a range of different surface textures, predominately based on the lithotype. Bright banded coal displayed a smooth surface compared to dull banded coal which had a rougher more fractured surface.…”

Section: 53mentioning

confidence: 99%

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The Effect of Water Occlusion on Gas Production in Coal

Mahoney¹

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Relative permeability is of fundamental importance to understand and model the flow of hydrocarbons and water in porous rocks including coal, and thus relative permeability is critical in prediction of commercial gas and water production rates from coal seam gas (CSG) reservoirs.Despite relative permeability being a primary parameter for determining reservoir performance, the fundamental physics of how or where water may occlude or block cleats in a coal seam, and thereby interfere with gas production rates, is not fully understood. This project aims to improve the understanding of water occlusion in CSG reservoirs through fluid experiments with model coal cleats and to evaluate the potential impact of water occlusion of reservoir performance.The aim of this thesis is to develop a new experimental methodology that can be used identify the main control factors that affect wettability in coal. There are two key objectives to satisfy the thesis aim 1) develop methods to make artificial channels in coal and 2) create a world first microfluidic device that assess micro scale flow through coal cleats, known as the cleat flow cell (CFC). The initial features to be evaluated will include: lithotype, surface roughness, surface composition, specifically chemical functional groups and pressure. oxygen plasma with a photolithography process to make the desired pattern on coal surface, UV Laser ablation, mechanical machining, a mechanical scratch technique, and a chemical etching technique that used potassium permanganate (KMnO4). Characteristics of the artificial channels were assessed using a surface step profiler, scanning electron microscopy, micro-Raman spectroscopy and light microscopy. A sixth methodology to create an artificial channel using pressed coal powder was also used as a means of evaluating the influence of the surface chemistry on the wetting behaviour, without the interference of surface topography.In Chapter Five, I report the effect of rank and lithotype on the wettability of coal in microfluidic experiments in two types of artificial microchannels; (1) reactive ion etched (RIE) channels and (2) die-cast channels prepared by pressing powdered lithotype concentrates. Contact angles and entry pressures of air and water in the artificial cleats were measured in imbibition experiments performed iii with a CFC. The relative contact angles measured in CFC imbibition experiments were in the range 110 -140° in the RIE channels and 85°-115° in the pressed discs, which are larger contact angles than measured on the flat bulk surfaces of these samples by the conventional sessile drop technique (58°-85°). The CFC observations show that the surface roughness of coal in inertinite-rich dull bands effects contact angle and the entry pressure of the air-water interface differently to the vitrinite-rich bright bands, with both lithotypes presenting unique wetting states. Drainage experiments revealed a thin residual water film on the inertinite cleat wall, not observed on the smoother vitrinite channel. were hydr...

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Mass transfer in coal seams for CO₂ sequestration

Wang¹,

Zhu²,

Massarotto³

et al. 2007

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).CO 2 sequestration in coal seams is a relatively new technique to simultaneously achieve enhanced coal bed methane production and reduced CO 2 emission. In this article, we integrate understandings in individual research fields to provide improved insight into the nature of this complex process. Our current overall model constructed from a number of sub-models consists of mass transfer in four pore types, namely, fractures, micro-, meso-, and macro-pores, all having pore size dependent characteristics. Key parameters are estimated using well established methods from the general literature. Three mechanisms of coal swelling leading to permeability variations during adsorption are proposed based on molecular simulations. The macroscopic level model is validated using a true tri-axial stress coal permeameter, which provides previously unpublished, accurate dynamic measurements of systems properties in three orthogonal directions including changes to the coal matrix volume. The integrated model provides a more complete and flexible representation for this complex system.

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Coal microstructure and micropermeability and their effects on natural gas recovery

Cited by 228 publications

References 7 publications

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

The Effect of Water Occlusion on Gas Production in Coal

Mass transfer in coal seams for CO₂ sequestration

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Coal microstructure and micropermeability and their effects on natural gas recovery

Cited by 228 publications

References 7 publications

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential

The Effect of Water Occlusion on Gas Production in Coal

Mass transfer in coal seams for CO2 sequestration

Contact Info

Product

Resources

About

Mass transfer in coal seams for CO₂ sequestration