Mathematical modelling of in situ combustion and gasification

Perkins, Greg

doi:10.1177/0957650917721595

Cited by 14 publications

(2 citation statements)

References 73 publications

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“…The shaft-less (drilling-type) UCG mode is to use drilling technology to build injection and production wells in the coal seam, and then establish a gasification channel between the two wells by linking methods including reverse combustion, electric resistive heating, hydraulic fracturing, and directional drilling [9,10]. As shown in Figure 1, the drilling-type UCG mode can be divided into the linked-vertical-wells (LVW) technique and controlled-retractable-injection-point (CRIP) technique according to the layout of gas injection wells.…”

Section: Cavity Growth Mechanismmentioning

confidence: 99%

A Review of Research on Cavity Growth in the Context of Underground Coal Gasification

Fang¹,

Liu

Ge³

et al. 2022

Energies

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Underground Coal Gasification (UCG) is a leading-edge technology for clean and effective utilization of coal resources, especially for deep coal seams with a depth of more than 1000 m. Since the core operation place of UCG is the cavity, mastering the cavity growth pattern is a prerequisite to ensure the efficient and economic development of UCG. At present, scholars have conducted numerous research works on cavity growth, but the simulation conditions limit the research results. Hence, it is necessary to summarize and sort out the research results of cavity growth patterns, which contribute to deepening the understanding of UCG and pointing out the direction for subsequent research. First of all, this paper summarizes the development history of UCG technology and describes the cavity growth mechanism from chemical reactions and thermo-mechanical failure. Then, the research methods of cavity growth are summarized from three aspects: a field test, laboratory experiment, and numerical simulation. The results show that the appearance of the cavity is teardrop-shaped, and its growth direction is obviously related to the gas injection method, including the injection direction and rate. Subsequently, the factors affecting the cavity growth process are expounded from the geological factors (permeability, moisture content, and coal rank) and operating factors (temperature, pressure, gasification agent’s composition, and gasification agent’s flow pattern). Finally, the existing problems and development trends in the cavity growth are discussed. The follow-up research direction should focus on clarifying the cavity growth mechanism of the controlled-retractable-injection-point (CRIP) method of UCG in the deep coal seam and ascertain the influence of the moisture content in the coal seam on cavity growth.

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Section: Cavity Growth Mechanismmentioning

confidence: 99%

A Review of Research on Cavity Growth in the Context of Underground Coal Gasification

Fang¹,

Liu

Ge³

et al. 2022

Energies

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“…The results showed that the relative error between the calculated value and the measured value was below 15 %, except for the measured points near the flameworking face. The combustion mathematical modeling and in situ gasification was described in [12]. Chemical reactions in multiphase porous media were simulated in this work.…”

Section: Introductionmentioning

confidence: 99%

Modeling of Material Balance From the Experimental Ucg

et al. 2020

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The underground coal gasification is a continually evolving technology, which converts coal to calorific gas. There are many important parameters in this technology, which are difficult to measure. These parameters include the underground cavity growth, amount gasified coal, and the leakage of input and output gaseous components into the surrounding layers during the coal gasification process. Mathematical modeling of this process is one of the possible alternatives for determining these unknown parameters. In this paper, the structure of the mathematical model of laboratory underground coal gasification process from the material balance aspect is presented. The material balance consists of mass components entering and leaving from the UCG process. The paper shows a material balance in the form of a general mass balance and atomic species balance. The material balance was testing by six UCG laboratory experiments, which were realized in two ex-situ reactors.

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