Ground movements associated with large-scale underground coal gasification

Technical Report · Fri Sep 01 04:00:00 EDT 1989

DOI:https://doi.org/10.2172/6778771· OSTI ID:6778771

Siriwardane, H J; Layne, A W

The primary objective of this work was to predict the surface and underground movement associated with large-scale multiwell burn sites in the Illinois Basin and Appalachian Basin by using the subsidence/thermomechanical model UCG/HEAT. This code is based on the finite element method. In particular, it can be used to compute (1) the temperature field around an underground cavity when the temperature variation of the cavity boundary is known, and (2) displacements and stresses associated with body forces (gravitational forces) and a temperature field. It is hypothesized that large Underground Coal Gasification (UCG) cavities generated during the line-drive process will be similar to those generated by longwall mining. If that is the case, then as a UCG process continues, the roof of the cavity becomes unstable and collapses. In the UCG/HEAT computer code, roof collapse is modeled using a simplified failure criterion (Lee 1985). It is anticipated that roof collapse would occur behind the burn front; therefore, forward combustion can be continued. As the gasification front propagates, the length of the cavity would become much larger than its width. Because of this large length-to-width ratio in the cavity, ground response behavior could be analyzed by considering a plane-strain idealization. In a plane-strain idealization of the UCG cavity, a cross-section perpendicular to the axis of propagation could be considered, and a thermomechanical analysis performed using a modified version of the two-dimensional finite element code UCG/HEAT. 15 refs., 9 figs., 3 tabs.

• Research Organization: USDOE Morgantown Energy Technology Center, WV (USA)
• Sponsoring Organization: DOE/MET
• OSTI ID: 6778771
• Report Number(s): DOE/METC-90/4101; ON: DE90009685
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
010900 -- Coal
Lignite
& Peat-- Environmental Aspects
APPALACHIAN BASIN
CARBONACEOUS MATERIALS
COAL
ENERGY SOURCES
FEDERAL REGION V
FINITE ELEMENT METHOD
FOSSIL FUELS
FUELS
GASIFICATION
GEOLOGIC STRUCTURES
GROUND MOTION
GROUND SUBSIDENCE
ILLINOIS
IN-SITU GASIFICATION
IN-SITU PROCESSING
MATERIALS
MATHEMATICAL MODELS
MOTION
NORTH AMERICA
NUMERICAL SOLUTION
PROCESSING
SEDIMENTARY BASINS
THERMOCHEMICAL PROCESSES
USA