Production performance analysis of horizontal drainage wells for the degasification of coal seams
The production performances of horizontal drainage wells for the degasification of coal seams have been investigated with the aid of a multidimensional, two-phase coal seam degasification model. The model is written in rectangular coordinates and can handle a number of horizontal wells and operates in a one-, two-, or three-dimensional mode. The model accommodates multiple horizontal boreholes originating from a common vertical shaft or horizontal boreholes being drilled from the peripheries of the reservoir. In consideration of relatively thin but large lateral extent of coal seams, flow dynamics around a horizontal borehole is described in elliptical flow geometry. The non-linear system of equations generated by the finite difference approximation are solved fully implicitly using Newton's iteration. In the mathematical formulation of the problem, coal seam was treated as a dual-porosity system. Transport of methane in the micropore structure of the coal was described by Fick's Law of diffusion while flow in the more permeable natural fracture network of the coal seam was formulated by Darcy's Law. A quasi-steady state kinetic model was included to represent the desorption of methane from coal grains.
- Research Organization:
- Pennsylvania State Univ.
- OSTI ID:
- 6973366
- Report Number(s):
- CONF-861080-
- Resource Relation:
- Conference: Society of Petroleum Engineers annual technical conference and exhibition, New Orleans, LA, USA, 5 Oct 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
01 COAL, LIGNITE, AND PEAT
BOREHOLES
FLOW MODELS
HYDRODYNAMICS
INCLINATION
COAL SEAMS
DEGASSING
METHANE
RECOVERY
COMPUTERIZED SIMULATION
DARCY LAW
DESORPTION
DIFFUSION
FICK LAWS
FINITE DIFFERENCE METHOD
INJECTION WELLS
MICROSTRUCTURE
PERFORMANCE
PERMEABILITY
POROSITY
PRODUCTION
ALKANES
CAVITIES
COAL DEPOSITS
CRYSTAL STRUCTURE
FLUID MECHANICS
GEOLOGIC DEPOSITS
HYDROCARBONS
ITERATIVE METHODS
MATHEMATICAL MODELS
MECHANICS
MINERAL RESOURCES
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
RESOURCES
SIMULATION
WELLS
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