Application of geostatistical methods in spatio-temporal modelling of temperature changes of UCG experimental trial

• Published in: Measurement : journal of the International Measurement Confederation Vol. 171; p. 108826
• Main Authors: Laciak, Marek, Vízi, Ladislav, Kačur, Ján, Durdán, Milan, Flegner, Patrik
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01-02-2021; Elsevier Science Ltd
• Subjects: Animation; Coal gasification; Coal mining; Experimental equipment; Geostatistical modelling; Geostatistics; Heat transfer; Kriging; Modelling; Oxidation; Semivariography; Synthesis gas; Tectonics; Temperature; Thermocouples; Underground coal gasification; Temperature; Semivariography; Underground coal gasification; Geostatistical modelling; Experimental equipment; Kriging
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2020.108826

•Experimental equipment for ex-situ UCG reactor was described.•Determining the velocity of movement of the combustion queue.•Possibility to identify places with the high temperature in the coal seam.•Determination of gasification zones in coal seam.
Underground coal gasification (UCG) technology enables coal to the extracted from underground seams that are too deep or affected by tectonic disturbances. In the underground, coal is transformed into syngas with gasification agents and subsequently extracted to the surface. The paper describes the use of geostatistical methods of modelling for the analysis of the UCG process. Based on the geostatistical theory and utilization of Isatis's geostatistical environment, a spatio-temporal model of temperature changes in the experimental generator during the UCG process in laboratory conditions was constructed. For the construction of this model, data from the experiment were used. From the measured data, temperatures obtained from thermocouples placed in the experimental generator were processed. A spatio-temporal model of temperature changes or temperature slices obtained from this model was used to analyze and subsequently calculate the combustion front movement during the experiment. Individual time slices of temperatures were analyzed in ArcGIS-ArcMap environment. Based on the visualization of these slices, an animation of temperature propagation and movement of temperature zones in time and space was created, which represents a view of the resulting process dynamics. It is clear from the model results that shortly after the experiment, two oxidation zones were created - left and right. From the calculated motion vectors of the front, a cyclic movement in the clockwise direction of the left oxidation zone is evident, with the highest movement velocity occurring at approximately half the duration of the experiment.