Dynamic gas slippage: A unique dual-mechanism approach to the flow of gas in tight formations
A mathematical formulation, applicable to both numerical simulation and transient well analysis that describes the flow of gas in very tight porous media and includes a dual-mechanism transport of gas is developed. Gas is assumed to be traveling under the influence of a concentration field and a pressure field. Transport through the concentration field is a Knudsen flow process and is modeled with Fick's law of diffusion. Transport through the pressure field is a laminar process and is modeled with Darcy's law (inertial/turbulent effects are ignored). The combination of these two flow mechanisms rigorously yields a composition-, pressure-, and saturation-dependent slippage factor. The pressure dependence arises from treating the gas as a real gas. The derived dynamic slippage is most applicable in reservoirs with permeabilities less than or equal to0.01 md. The results indicate that in reservoirs of this type, differences between recoveries after 10 years of production with the dynamic-slip and constant-slip approaches were as great as 10%, depending on the initial gas saturation. If an economic production rate is considered, differences as great as 30% can be expected.
- Research Organization:
- Pennsylvania State Univ.
- OSTI ID:
- 5597779
- Journal Information:
- SPE (Society of Petroleum Engineers) Format. Eval.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Format. Eval.; (United States) Vol. 1:1; ISSN SFEVE
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dynamic gas slippage: a unique dual-mechanism approach to the flow of gas in tight formations
Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs
Related Subjects
030200* -- Natural Gas-- Reserves
Geology
& Exploration
CALCULATION METHODS
DARCY LAW
DIFFUSION
ECONOMIC ANALYSIS
ECONOMICS
FICK LAWS
FLOW MODELS
FLUID FLOW
GAS FLOW
GAS SATURATION
GEOLOGIC DEPOSITS
KNUDSEN FLOW
LAMINAR FLOW
MATERIALS
MATHEMATICAL MODELS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NATURAL GAS WELLS
PERMEABILITY
POROSITY
POROUS MATERIALS
PRESSURE DEPENDENCE
RESERVOIR PRESSURE
RESOURCES
SATURATION
SLIP
WELLS