Report 96(simulation Of N2 Diffusion Exp. With Convection At M-f Boundary)

1 Ahmad Jamili

Report # 96

Date: 11/10/09

Subject: Simulating the diffusion experiment Conclusion: Comparing magnitude of diffusion and convection mechanisms at 8 day and 28 day showed: 1-

At 8 day, gas molecular diffusion is the most important mechanism in transporting N2 and C1 in the porous media. Oil convection is the dominant mechanism responsible for C5 flow in the core. This conclusion is valid for both with and without convection at matrix-fracture boundary.

2- At 28 day, gas molecular diffusion still is the most important mechanism when no convection boundary applied between matrix and fracture. However, gas convection becomes the most important mechanisms in the case of convection boundary between matrix and fracture. 3- At 28 day, oil convection still is the main mechanism for carrying C5 in porous media. The role of gas convection is noticeable especially at the end of the core when convection between matrix and fracture is allowed. 4- When convection flow between matrix and fracture included in the model, the role of gas convection from fracture to matrix becomes important as time advances. This mechanism contributes negatively to recovery of C1 and C5 from the core.

Problem description

2 L(m) nx dx(m) dz(m) dy(m) Matrix Porosity Matrix permeability (md) Matrix Vp,m3 Fracture V, m3 dx(m), Fracture Total Vp,m3

0.357 20 0.01785 0.031937439 0.031937439 0.4 2 0.000145656 0.00001 0.0098039 0.000155656

Initial conditions So, matrix Sg, matrix So, fracture Sg, fracture Overall composition, Z C1 Overall composition, Z C5 yC5, matrix yC1, matrix xC5, matrix xC1, matrix gasdens,matrix (kg/m3) gasdens, fracture (kg/m3) oildens, matrix (kg/m3) MWg, fracture MWg, matrix Mwo, matrix C5mole C1mole Total mole Total mass IFT0 (dynes/cm) IFT, initial (dynes/cm) Initial pressure (psi) Temperature (F)

0.749 0.251 1.00E-15 1.000000 52.4 47.6 0.055467826 0.944532174 0.541821364 0.458178636 94.3 113.3259166 489.4 28.47351662 19.15518877 46.4435131 0.00063291 0.00069673 0.0013 0.0568 2.9 2.3406 1479 100.33

Problem Layout Fractur

Matrix

3 e Mass transfer coefficient between fracture and matrix: N2 C1 C5

mol/day 4.67x10^-5 12.02x10^-5 20.64x10^-5

m3/day 1.169x10^-5 3.004x10^-5 5.159x10^-5

kg/day 1.31x10^-3 3.37x10^-3 5.8x10^-3

C1

C5

4

5