Finite-element analysis of two-phase fluid flow in naturally fractured reservoirs

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6352716

Bhatia, K S

Fluid flow simulation through naturally fractured reservoirs has been investigated for nearly four decades. This study is important in applications involving oil and gas recovery from naturally fractured reservoirs, transport of hazardous waste and coal seams degasification. The numerical simulation of the flow response of multiphase, immiscible fluids is therefore highly significant. The mathematical characterization of a naturally fractured reservoir is realized by superimposing two interacting continuous media, one of which represents a low porosity and high permeability flow path, called the fracture continuum and the other representing a high storage and low permeability medium, called the matrix blocks. The complexity of the reservoir description and the two phase fluid flow governing equations yields a system of nonlinear differential equations. These equations are solved numerically by the finite element method, utilizing the Galerkin-Newton-Raphson numerical scheme. The developed computer code is initially validated by neglecting the fluid interaction between the two superimposed continua. The resulting two-phase fluid flow description through a conventional unfractured reservoir is verified by comparison with one and two dimensional problems reported in the literature. Furthermore, by evaluating the interaction term coupling the fracture and matrix blocks, dual porosity and dual permeability models are also deduced. For example, in coal seam degasification, two phase fluid (water and gas) flow occurs in the fracture continuum whereas the matrix blocks are virtually impermeable to the flow of water. The desorbed gas from the matrix blocks constitutes distributed sources for the fracture. The finite element formulation for coal seam degasification in the presence of an induced fracture is presented.

• Research Organization: Ohio State Univ., Columbus, OH (USA)
• OSTI ID: 6352716
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
54 ENVIRONMENTAL SCIENCES
540320 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
COMPUTER CODES
DIFFERENTIAL EQUATIONS
EQUATIONS
FINITE ELEMENT METHOD
FLUID FLOW
FRACTURED RESERVOIRS
NUMERICAL SOLUTION
PERMEABILITY
RECOVERY
SIMULATION