US 10,371,859 B2 · Method for simulation of microscopic flow of pre-crosslinked gel suspension liquid in porous medium

Abstract

Disclosed is a method for simulation of a microscopic flow of pre-crosslinked gel suspension liquid in a porous medium, including the steps of: establishing a simulation area of the porous medium based on a two-dimensional core CT slice image and subjecting the simulation area to numerical grid discretization; setting initial position and original shape of pre-crosslinked gel particles to generate virtual boundary mark points; marking the type of numeric grid nodes; calculating the force of the fluid on each virtual boundary mark point according to the momentum change of the numerical grid nodes on the boundary of the pre-crosslinked gel particles; calculating the contact force on each virtual boundary mark point using a particle contact action model; calculating the bending recovery force and the stretching recovery force for each virtual boundary mark point based on the current shape and original shape of the pre-crosslinked gel particles; and calculating the velocity and displacement of each virtual boundary mark point based on Newton's second law, wherein the respective virtual boundary mark points are connected to obtain the overall shape and position of the pre-crosslinked gel particles.

A computer-implemented method for simulation of a microscopic flow of pre-crosslinked gel suspension liquid in a porous medium, the pre-crosslinked gel suspension liquid containing one or more pre-crosslinked gel particles, the method comprises the steps of:

(1) using a processor to generate a simulation area of the porous medium based on a computer-readable two-dimensional core CT slice image and subjecting the simulation area to numerical grid discretization, such that the simulation area has a finite number of computing numeric grid nodes;
(2) setting initial position and original shape of each of the one or more pre-crosslinked gel particles to generate virtual boundary mark points of the each of the one or more pre-crosslinked gel particles;
(3) marking type for numeric grid nodes in the simulation area subjected to the numerical grid discretization, the type including intra-particle node, particle boundary node, intra-fluid node, and fluid boundary node;
(4) calculating a force Ff of fluid on each of the virtual boundary mark points according to momentum change of particle boundary nodes within a control range of each virtual boundary mark point, wherein the force of fluid on each virtual boundary mark point is calculated according to the following formula:
F
f
=
(
Δ
⁢
⁢
x
)
2
Δ
⁢
⁢
t
⁢
∑
k
=
1
p
⁢
⁢
V
s
/
V
t
⁡
(
τ
-
1
/
2
)
(
1
-
V
s
/
V
t
)
+
(
τ
-
1
/
2
)
⁢
∑
j
=
0
8
⁢
⁢
C
j
⁢
l
j
wherein Δx represents a grid step size;
Δt represents a time step size;
p represents a number of particle boundary nodes within control range of the each virtual boundary mark point;
Vt represents a total volume of a control unit having a length of Δx and centered on the particle boundary node;
Vs represents a volume of a portion of the control unit covered by the pre-crosslinked gel particle;
τ represents relaxation time;
Cj represents an additional collision term;
and lj represents a discrete velocity in a j direction;
(5) calculating a contact force Fp on each of the virtual boundary mark points using a particle contact action model;
(6) calculating a bending recovery force Fb and a stretching recovery force Fs for each of the virtual boundary mark points;
(7) calculating a velocity u and a displacement x of each of the virtual boundary mark point based on Newton's second law, the force Ff , the contact force Fp , the bending recovery force Fb and the stretching recovery force Fs of the each virtual boundary mark point, simulating movement of the each virtual boundary mark point according the velocity u and the displacement x thereof, and connecting respective virtual boundary mark points of the each of the one or more pre-crosslinked gel particles to obtain an overall shape and position of the each of the one or more pre-crosslinked gel particles as a simulation result;
(8) repeating steps (4) to (7) and calculating a relative error of the two most recent simulation results therefrom until the relative error is less than 0.01 or a number of repeation iterations is greater than 100,000;
and
(9) outputting the most recent simulation result.

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Method for simulation of microscopic flow of pre-crosslinked gel suspension liquid in porous medium

Life of this patent

Method for simulation of microscopic flow of pre-crosslinked gel suspension liquid in porous medium

Life of this patent

Abstract

Claims6