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Editor's column The most recent report from the United Nation’s Intergovernmental Panel on Climate Change and December’s international conference on climate change held in Katowice, Poland, show that the world is not coming close to reaching the targets set in the landmark Paris Agreement of 2015. Many governments are now calling for aggressive and immediate measures to avoid what they fear could be the catastrophic consequences of climate change. This sense of urgency could breathe new life into carbon capture and storage, a technology hailed by the oil and gas industry that has gained little traction in the past decade. Carbon capture and storage involves capturing carbon dioxide from large sources such as power plants or other industry, transporting it to a storage site, and burying it to keep it from entering the atmosphere. Storage, or sequestration, of the CO2 would most likely be in deep geological formations, or possibly in the ocean. The US National Energy Technology Laboratory has reported that North America alone could store 900 years’ worth of carbon dioxide underground. It is a potentially cost-effective way to decarbonize industries such as petrochemicals, cement, steel, and power generation. The idea is that this would help mitigate CO2 emissions from hydrocarbons and would complement other alternative energy solutions as momentum builds for a carbon-constrained world. The technology has had broad oil and gas industry support for over a decade. The Oil and Gas Climate Initiative—whose members include 13 major oil companies including BP, Shell, ExxonMobil, Saudi Aramco, and Equinor—has long touted the method and recently held a workshop on the potential of carbon capture in the Middle East. Participants discussed how governments in the region and industry can create clean and sustainable industries by capturing carbon dioxide from oil and gas production and use. Even though the idea is not new, carbon capture is often seen as unworkable because of the cost and concerns about the effects of storage. But the UN recently cited the technology as one of numerous ideas to combat climate change. “It’s about changing the way people look at CCS from thinking that it is kind of inevitable but impossible and turning into kind of necessary and doable,” Fiona Wild, the head of climate change and sustainability at BHP Billiton, said at an industry conference in November. “We need to get policy regimes in place that support development over the longer term because we need scale.” Other attendees at that conference were executives from the International Energy Agency, BP, Shell, Total, Equinor, and the British Energy Ministry. All were in agreement that the time is right to revitalize interest in the technology. Meanwhile, projects are slowing moving forward. The Climate Initiative recently entered into a strategic partnership with several major oil companies to promote the Clean Gas Project, the UK’s first commercial full-chain carbon capture and storage project. And, in late November, ADNOC announced that it would expand carbon capture and storage from either a major gas processing facility or the Shah gas plant.
The most recent report from the United Nation's Intergovernmental Panel on Climate Change and December's international conference on climate change held in Katowice, Poland, show that the world is not coming close to reaching the targets set in the landmark Paris Agreement of 2015. Many governments are now calling for aggressive and immediate measures to avoid what they fear could be the catastrophic consequences of climate change. This sense of urgency could breathe new life into carbon capture and storage, a technology hailed by the oil and gas industry that has gained little traction in the past decade. Carbon capture and storage involves capturing carbon dioxide from large sources such as power plants or other industry, transporting it to a storage site, and burying it to keep it from entering the atmosphere. Storage, or sequestration, of the CO2 would most likely be in deep geological formations, or possibly in the ocean.
ABSTRACT: The paper deals with the total load-bearing capacity of steel arch yielding supports of roadways which is inevitable for design of the roadway support. The authors compared results of a finite element (FE) model they developed with results of experimental tests of steel arch supports in laboratory. Computer modelling of the load-bearing capacity of the steel arch support was performed using the massively scalable strongly nonlinear solver MARC. The finite element models of the arch supports and stirrups were created and assembled according to drawings without shape simplification. An experimental investigation was realized in the Laboratory of Mechanical Devices Testing at GIG Katowice. The computer model of the steel arch support captures very well the strength and deformation behaviour of the arch support. The value of the loading capacity of the yielding arch supports at the moment of first slip represents with sufficient accuracy the total load-bearing capacity of arch supports at the specified loading conditions. The mathematical modelling facilitates reliable parametric studies of the steel arch support's total load bearing capacity from the viewpoint of construction, shape, material, optimal yielding connections and a scheme of loading. 1 INTRODUCTION Design of steel arch support of roadways is important in coal and ore mining and also tunnelling (small size galleries). Geomechanical methods based on empirical and analytical procedures (mostly in coal mining – Junker 2009) and static calculations (in underground engineering) facilitate to specify a loading of support constructions. The assessment of real load-bearing capacity of rigid or yielding steel arch support is necessary for optimal design. 2 THE TOTAL LOAD-BEARING CAPACITY OF YIELDING STEEL ARCH SUPPORT The total bearing capacity of the support frame is ultimate sum of external forces in the moment of the first slip in yielding joints or non-elastic deformation of some support segment. The ultimate bearing capacity of arch supports depends not only on the construction (it means size, material, construction of yielding joints etc.) The bearing capacity of steel arch supports is also affected by the way of loading and the quality of a contact of the support with the surrounding rock. Laboratory testing of steel arch supports on big hydraulic frames (which have recently become available in the Central Mining Institute Katowice, Poland and DMT Essen, Germany) gives real data on the behaviour and load-bearing capacity of support constructions. Experimental measurements are significantly expensive and time-consuming and we tried to use computer modelling the task by FEM (Finite Element Method). Methods of computer modelling, with efficient programs, are becoming recognised as suitable for comparison of different constructions of roadway supports under various loadings. Modelling of a whole yielding support construction is exacting and also demands verification based on testing results. The authors here present results from both testing and computer modelling of the standard four-segment steel arch support of roadways.
Didier, C. (INERIS) | Van Der Merwe, J.N. (Bon-Terra Mining (Pty) Ltd) | Betournay, M. (CANMET) | Mainz, M. (IHS Consulting, Germany) | Aydan, O. (Tokai University) | Song, W-K. (KIGAM) | Kotyrba, A. (Central Mining Institute,) | Josien, J-P. (GEODERIS)
ABSTRACT In 2005, Prof. Nielen Van der Merwe, at that time President of the ISRM, initiated a commission to facilitate the constitution of an international network of experts involved in mine closure and post-mining management. Eight experts coming from different countries have been deeply involved in this ISRM "mine closure commission", for four years. Closure of mining operations does not lead to the complete elimination of risks likely to affect the surface above old mine workings. Therefore, disorders potentially harmful for people and goods may develop, sometimes just after the closure but also, in some cases, long time after. The first mandate of the commission has been dedicated to the elaboration of a state-of-the- art report presenting, at an international scale, the mine closure problem (context, main risks of disorders, major hazard assessment methods and treatment techniques). The present paper presents an outline of this ISRM report that members may download on the ISRM website. 1 INTRODUCTION 1.1 Commission constitution and objectives The mine closure Commission has been appointed with two main objectives. The first one was to facilitate contacts between experts in rock mechanics from different countries concerned with post mining management in order to create opportunities to exchange experiences, case studies and scientific data. The second objective of the commission was to elaborate a reference document, presenting the international "state-of-the-art" for existing techniques and methods enabling identification, characterisation and management of geotechnical hazards related to mine closure processes (Didier et al., 2008). An expert panel has thus been constituted to elaborate the document. All the members that joined the commission got involved on a strictly voluntary basis and gave considerably of their time and their expertise to the benefit of the commission work. They are listed below:Christophe DIDIER, INERIS, Verneuil-en-Halatte, France. President of the Commission. Nielen Van der MERWE, Bon-Terra Mining Ltd, South-Africa. Past President of the ISRM. Ömer AYDAN, Tokaï University, Shizuoka, Japan. Marc BÉTOURNAY, CANMET, Mining and Mineral Sciences Laboratories, Ottawa, Canada. Jean-Pierre JOSIEN, GEODERIS, Metz, France. Andrej KOTYRBA, Central Mining Institute, Katowice, Poland. Mark MAINZ, IHS (Ingenieurbuero Heitfeld- Schetelig), Aachen, Germany. Won-Kyong SONG, Korea Instit. of Geoscience and Min. Resources, Daejeon, Korea. 1.2 Content of the report The mine closure state-of-the-art report contains 7 sections and 3 appendices. After a brief presentation of the mine closure context, at an international scale, the document describes precisely the most frequent geomechanical hazards that may develop above an abandoned mine. In addition to the description of consequences and potential effects on people and surface structures, the basic mechanisms that may initiate the failure are discussed. The commonly used hazard assessment methods are then described, with a particular attention to the key factors that have to be taken into account in the assessment process. Classical post-mining risk management methods are then discussed: voids treatment, monitoring methods, land use management. Specific references are included at the end of each section and recommended additional literature is also given.
Abstract This case history paper describes a technique that minimizes the creation of multiple fractures in deep coal seams during hydraulic fracturing operations. The technique enabled the operator and the service company to perform 24 nitrogen foam-fluid fracturing treatments in 33 days in the Upper Silesian basin (Poland). The creation of multiple fractures is a phenomenon often encountered during fracturing operations in coal seams and is the most probable cause of early screenouts. During this fracturing campaign, early screenouts were observed at sand concentrations less than 3 lb/gal. These screenouts were attributed to a lack of fracture width caused by the presence of multiple fractures, including possible horizontal fracture components or tortuosity. The operator and the service company developed a technique that involves pumping a small volume of highly viscous crosslinked gel before the main fracturing treatment. This technique prevented early screenouts and allowed the higher sand concentrations to be pumped. Introduction The operator won a concession to explore for coalbed methane in the Upper Silesian Basin of southern Poland in September 1993 (Figure 1). Following negotiation of various terms, the concession became effective in late August 1994 and drilling commenced in November 1994. The project targeted the coal-bearing strata of the Carboniferous era. Various seams of these strata have been actively mined for over one-hundred years in this area of Poland, with numerous shows of gas, fires and explosions. The concession consists of 487 km2 just south of the town of Katowice with active coal mines immediately to the east of the concession, and one active coal mine (Silesia Mine) surrounded by the concession area (Figure 2). The objective of this work was to sample the coalbed methane productivity of the concession in order to determine the economic potential for a development project that would consist of a couple hundred wells. The stratigraphy in the area consists of over 60 coal seams of 0.5-m or greater thickness over an approximately 1000-m interval. A statistical sampling was needed because of three reasons:–the mandate to evaluate the resource in a period of less than three years with a total of only 15 wellbores –the significant amount of coal –the anticipated variability of various coalbed methane parameters such as gas capacity, saturation, permeability, and production rate Based on the operator's experience in the San Juan and Warrior Basins, fracture stimulations were the preferred completion method for coalbed methane wells. Historically there had been very few fracture stimulations performed in Poland. and no fracturing equipment or experienced crews were available. With respect to perforating, there was no referencing of performance data to API standards. Thus the project needed to import these services with the associated high mobilization charges. Because of this high fixed-cost component, individual seam or zone completions were too costly and multiple-zone well completion campaigns were chosen. To reduce mobilization costs, a campaign approach for treating the selected intervals was chosen. This paper describes which problems were encountered during a campaign that involved treating 24 intervals in six of the eight test wells and how these problems were solved. The original plan for evaluation of the concession provided for seven coreholes to determine the basic gas capacity and isotherm information, and eight test wells for production testing. P. 161^
Abstract. Coal beds and methane-both free and adsorbed in coal, appear in the south of Poland in the Upper Carboniferous in two basins: Upper Silesian Coal Basin (USCB) and Lower Silesian Coal Basin (LSCB). At the depth of 3o(r1600 m the methane reserves are estimated at 350 to 1300 rnld m3 for USCB and ca. 20 mld m3 for LSCB. Methane content in coal varies between O and 22 m3/tpc, to significantly increase from the depth of 600 m, reaching average values of 4.7-7.0 m3/tpc. Discrepancies in estimation are due to different calculation methods; the full geostatistical analysis methodstructural analysis-was not applied, however. Prognoses, apparently optimistic, determine the final recovery of methane from coal beds for ca. 5 mld m3/year for USCB, and ca. 300 min m3 for LSCB, which together with the production from the Polish gas reservoirs would give ca. 12 mld m3/year in the year 2010. For the comparison's sake, the Polish consumption of gas is now ca. 11.8 rnld m3, being about 9% of total primary fuel consumption in Poland. Methane from coal beds was recovered earlier but used in less quantities (ca. 190 mln m3/year). It came from 18 USCB mines. Utilization of methane from coal basins aims at the reorientation of the Polish energy industry to the increased use of hydrocarbon fuels. Besides, the use of methane, especially in the Upper Silesia region, will significantly improve the ecological situation, limiting the emissions of SO, CO, NO, and dusts. The priorities of methane utilization are as follow: delivery to local receivers, for households, near big agglomerations Katowice, Opole, Bielsko; heating, housing estates, country, balance top needs; for local industrial works, metallurgical, ceramic, chemical plants, glass works; electric generation. Now a few foreign companies are interested in methane exploitation in Poland, e.g. McCormick Energy Inc., USA, Amoco, Conoco, Electrogaz Ventures (Poland-USA), Metanel (Poland). There has been an auction of the licence for methane exploitation. The fact that methane appears in coal beds has been known since the beginning of the mining industry. The gas was generally treated as a considerable hindrance in the exploitation of coal as a fuel. It has created a great hazard'for the miners in the form of explosions and outbursts of rock and coal. For more than ten years the matter of methane enclosed in coal, treated as a fuel, has raised interest in many countries, e.g. U.S.A., Australia, China. Research has been carried out on the content in coal, ways of deposition as well as methods of exploitation and leakproof transport to the surface. Poland has also taken an interest in methane, coming from coal, as a fossil fuel. There are three coal basins in Poland (Fig. 1): - Upper Silesian Coa