Progress on a new integrated 3-D UCG simulator and its initial application

John J. Nitao, David W. Camp, Thomas A. Buscheck, Joshua A. White, Gregory C. Burton, Jeffrey L. Wagoner, Mingjie Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

16 Citations (Scopus)

Abstract

A comprehensive simulator is being developed for underground coal gasification (UCG), with the capability to support site selection, design, hazard analyses, operations, and monitoring (Nitao et al., 2010). UCG is computationally challenging because it involves tightly-coupled multi-physical/chemical processes, with vastly different timescales. This new capability will predict cavity growth, product gas composition and rate, and the interaction with the host environment, accounting for site characteristics, injection gas composition and rate, and associated water-well extraction rates. Progress on the new simulator includes completion and system integration of a wall model, a rock spalling model, a cavity boundary tracking model, a one-dimensional cavity gas reactive transport model, a rudimentary rubble heat, mass, and reaction model, and coupling with a pre-existing hydrology simulator. An existing geomechanical simulator was enhanced to model cavity collapse and overburden subsidence. A commercial computational fluid dynamics (CFD) code is being evaluated to model cavity gas flow and combustion in two and three dimensions. Although the simulator is midway in its development, it was applied to modeling the Hoe Creek III field test (Stephens, 1981) conducted in the 1970s, in order to evaluate and demonstrate the simulator's basic capabilities, gain experience, and guide future development. Furthermore, it is consistent with our philosophy of incremental, spiral software development, which helps in identifying and resolving potential problems early in the process. The simulation accounts for two coal seams, two injection points, and air and oxygen phases. Approximate extent and shape of cavity growth showed reasonable agreement with interpreted field data. Product gas composition and carbon consumed could not be simultaneously matched for a given set of parameter values due to the rudimentary rubble model currently used, although they can be matched using separate parameter sets. This result is not surprising and confirms plans for a more sophisticated rubble model as our next step, as well as adding geomechanical collapse modeling and higher accuracy cavity gas reactive transport models. The results are very encouraging and demonstrate that our approach is sound.

Original languageEnglish
Title of host publication28th Annual International Pittsburgh Coal Conference 2011, PCC 2011
Pages1644-1654
Number of pages11
Volume3
Publication statusPublished - 2011
Event28th Annual International Pittsburgh Coal Conference 2011, PCC 2011 - Pittsburgh, PA, United States
Duration: Sep 12 2011Sep 15 2011

Other

Other28th Annual International Pittsburgh Coal Conference 2011, PCC 2011
CountryUnited States
CityPittsburgh, PA
Period9/12/119/15/11

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology

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  • Cite this

    Nitao, J. J., Camp, D. W., Buscheck, T. A., White, J. A., Burton, G. C., Wagoner, J. L., & Chen, M. (2011). Progress on a new integrated 3-D UCG simulator and its initial application. In 28th Annual International Pittsburgh Coal Conference 2011, PCC 2011 (Vol. 3, pp. 1644-1654)