Effect of Fracture Intensity and Longitudinal Dispersivity on Mass Transfer in Fractured Reservoirs

2012 ◽  
Author(s):  
Amin Sharifi Haddad ◽  
Hassan Hassanzadeh ◽  
Jalal Abedi ◽  
Zhangxing Chen
Keyword(s):  
Mass Transfer ◽  
Fractured Reservoirs ◽  
Longitudinal Dispersivity ◽  
Fracture Intensity

Modeling Gas-Phase Mass Transfer Between Fracture and Matrix in Naturally Fractured Reservoirs

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 795-811 ◽  
Author(s):  
A.. Jamili ◽  
G.P.. P. Willhite ◽  
D.W.. W. Green
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Mass Transfer ◽  
Fractured Reservoirs ◽  
Porous Matrix ◽  
Naturally Fractured Reservoirs ◽  
Gravity Drainage ◽  
Liquid Phases ◽  
The Matrix ◽  
Diffusion And Convection

Summary Gas injection in naturally fractured reservoirs maintains the reservoir pressure and increases oil recovery primarily by gravity drainage and to a lesser extent by mass transfer between the flowing gas in the fracture and the porous matrix. Although gravity drainage has been studied extensively, there has been limited research on mass-transfer mechanisms between the gas flowing in the fracture and fluids in the porous matrix. This paper presents a mathematical model that describes the mass transfer between a gas flowing in a fracture and a matrix block. The model accounts for diffusion and convection mechanisms in both gas and liquid phases in the porous matrix. The injected gas diffuses into the porous matrix through gas and liquid phases, causing the vaporization of oil in the porous matrix, which is transported by convection and diffusion to the gas flowing in the fracture. Compositions of equilibrium phases are computed using the Peng-Robinson EOS. The mathematical model was validated by comparing calculations to two sets of experimental data reported in the literature (Morel et. al. 1990; Le Romancer et. al. 1994), one involving nitrogen (N2) flow in the fracture and the second with carbon dioxide (CO2) flow. The matrix was a chalk. The resident fluid in the porous matrix was a mixture of methane and pentane. In the N2-diffusion experiment, liquid and vapor phases were initially present, while in the CO2 experiment, the matrix was saturated with liquid-hydrocarbon and water phases. Calculated results were compared with the experimental data, including recovery of each component, saturation profiles, and pressure gradient between matrix and fracture. Agreement was generally good. The simulation revealed the presence of countercurrent flow inside the block. Diffusion was the main mass-transfer mechanism between matrix and fracture during N2 injection. In the CO2 experiment, diffusion and convection were both important.

A Critical Review for Proper Use of Water/Oil/Gas Transfer Functions in Dual-Porosity Naturally Fractured Reservoirs: Part I

2009 ◽  
Vol 12 (02) ◽  
pp. 200-210 ◽  
Author(s):  
Benjamin Ramirez ◽  
Hossein Kazemi ◽  
Mohammed Al-kobaisi ◽  
Erdal Ozkan ◽  
Safian Atan
Keyword(s):  
Mass Transfer ◽  
Oil Recovery ◽  
Transfer Functions ◽  
Fractured Reservoirs ◽  
Gas Injection ◽  
Naturally Fractured Reservoirs ◽  
Dual Porosity ◽  
Fine Grid ◽  
Matrix Block ◽  
The Matrix

Summary Accurate calculation of multiphase-fluid transfer between the fracture and matrix in naturally fractured reservoirs is a crucial issue. In this paper, we will present the viability of the use of simple transfer functions to account accurately for fluid exchange resulting from capillary, gravity, and diffusion mass transfer for immiscible flow between fracture and matrix in dual-porosity numerical models. The transfer functions are designed for sugar-cube or match-stick idealizations of matrix blocks. The study relies on numerical experiments involving fine-grid simulation of oil recovery from a typical matrix block by water or gas in an adjacent fracture. The fine-grid results for water/oil and gas/oil systems were compared with results obtained with transfer functions. In both water and gas injection, the simulations emphasize the interaction of capillary and gravity forces to produce oil, depending on the wettability of the matrix. In gas injection, the thermodynamic phase equilibrium, aided by gravity/capillary interaction and, to a lesser extent, by molecular diffusion, is a major contributor to interphase mass transfer. For miscible flow, the fracture/matrix mass transfer is less complicated because there are no capillary forces associated with solvent and oil; nevertheless, gravity contrast between solvent in the fracture and oil in the matrix creates convective mass transfer and drainage of oil. Using the transfer functions presented in this paper, fracture- and matrix-flow calculations can be decoupled and solved sequentially--reducing the complexity of the computation. Furthermore, the transfer-function equations can be used independently to calculate oil recovery from a matrix block.

Influence of Wettability and Flow Rate Changes in the Mass Transfer for Simulation of Fractured Reservoirs

2020 ◽  
Author(s):  
Sharon A. R. Soler ◽  
Luís F. Lamas ◽  
Erika T. Koroishi ◽  
Eddy Ruidiaz ◽  
Osvair Vidal Trevisan ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Fractured Reservoirs
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