Development, testing, and application of a multi-well numerical coal seam degasification simulator
A series of mathematical formulations and numerical developments equipped with finite-difference approximation to simulate the simultaneous flow of gas and water in a coal seam and a tight gas formation is presented. The simulator employs a multi-dimensional, multi-phase formulation in rectangular coordinates and has options to accommodate a number of vertical wells as well as horizontal wells. For the vertical wells the model is able to handle the simulation of post-fracture performance through either horizontally or vertically fractured wells. Mining activity is also included to investigate methane emission at the mine working faces. Furthermore, options exist to include a number of impermeable geological barriers within the system. The transport of gas in coal seams can be formulated using a dual transport approach. In this approach, flow through macropores can be modeled with Darcy's law through the pressure field whereas flow through micropores can be modeled with Fick's law of diffusion through the concentration field. The combination of these two transport mechanisms extends the application range of these models to tight gas sand reservoirs. This is achieved by the exclusion of the kinetic sorption model. This quasi-steady state kinetic sorption model is included to represent the desorption of methane from coal grains. The developed numerical model has been tested and verified by using hypothetical reservoirs with increasing degrees of complexity and by history matching against the actual field data. Also, performance of the unconventional gas reservoir models has been compared against the performance of conventional gas reservoir models.
- Research Organization:
- Pennsylvania State Univ., University Park (USA)
- OSTI ID:
- 6379192
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Numerical simulation of the simultaneous flow of methane and water through dual porosity coal seams during the degasification process
Numerical simulation of the transient behavior of coal seam degasification wells
Related Subjects
03 NATURAL GAS
COAL SEAMS
DEGASSING
NATURAL GAS WELLS
SIMULATORS
DARCY LAW
DIFFUSION
EMISSION
FINITE DIFFERENCE METHOD
FRACTURED RESERVOIRS
FRACTURING
GAS FLOW
KINETIC EQUATIONS
LIQUID FLOW
MANY-DIMENSIONAL CALCULATIONS
MATHEMATICAL MODELS
METHANE
MINING
MULTIPHASE FLOW
PERMEABILITY
POROSITY
SANDSTONES
TESTING
USES
WATER
WORKING FACES
ALKANES
ANALOG SYSTEMS
COAL DEPOSITS
COMMINUTION
EQUATIONS
FLUID FLOW
FUNCTIONAL MODELS
GEOLOGIC DEPOSITS
HYDROCARBONS
HYDROGEN COMPOUNDS
ITERATIVE METHODS
MINERAL RESOURCES
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
WELLS
012033* - Coal
Lignite
& Peat- Underground Mining- Mine Environment- (1987-)
030900 - Natural Gas- Artificial Stimulation
Plowshare- (-1989)