Visualization system and method for multiphase fluids displacement experiment with large viscosity difference in complex pore structure

Patent metadata

Field	Value
Publication number	US-11307131-B2
Application number	US-202017296998-A
Country	US
Kind code	B2
Filing date	Apr 26, 2020
Priority date	Apr 26, 2020
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

A visualization system and method for a multiphase fluids displacement seepage experiment with large viscosity difference in a complex pore structure. The visualization system includes: an injection pump assembly, a visualized complex pore model, a vacuum pressure pump and an image acquisition device; the system and method are printed by a 3D printing device to form the visualized complex pore model with at least two permeability, and displacement fluid mediums of different viscosities are injected into the visualized complex pore model through different injection pumps during an experiment, so that not only is the penetration of the same viscosity in the complex pore structure with different permeability observed, but also the displacement and plugging effect of different viscosities successively entering the complex pore structure with different permeability is realized.

First claim

What is claimed is:

1. A visualization system for a multiphase fluids displacement seepage experiment with large viscosity difference in a complex pore structure, wherein the visualization system comprises: an injection pump assembly, a visualization complex pore model, a vacuum pressure device and an image acquisition device;
the visualization complex pore model comprises an inlet and an outlet, and an interior comprises at least two parts of a complex pore structure, and the permeability of each part of the complex pore structure is different;
the injection pump assembly comprises at least two injection pumps, outlets of the injection pumps are configured to be communicated with the inlet of the visualization complex pore model; the at least two injection pumps are configured to inject fluid mediums of different viscosities;
the vacuum pressure device is configured to provide a vacuum environment which allows a displaced fluid medium to be injected into the complex pore structure of the visualization complex pore model; and
the image acquisition device is configured to capture an experimental image inside the visualization complex pore model in a seepage process in real time, wherein the visualization complex pore model is formed by the following method:
scanning experimental samples with different permeability through a laboratory micro CT scanning system to obtain CT scanning images of the complex pore structure with different permeability;
capturing the CT scanning images respectively corresponding to different permeability in accordance with a predetermined ratio to form a grayscale image of the overall structure model by splicing;
performing image binarization processing on the grayscale image of the overall structure model formed by splicing to obtain a binary image constituting the complex pore structure; and
performing three-dimensional reconstruction of the binary image by a three-dimensional modeling software to obtain a digital model of the complex pore structure, and printing and forming the visualization complex pore model by using transparent materials in accordance with the digital model of the complex pore structure.

2. The visualization system for the multiphase fluids displacement seepage experiment with large viscosity difference in the complex pore structure according to claim 1 , wherein a first permeability zone, a second permeability zone, . . . and a Nth permeability zone are respectively captured from N CT scanning images, and the N permeability zone are successively spliced along a direction perpendicular to the flow of the medium to form the grayscale image of the overall structure, and the permeability decreases successively.

3. The visualization system for the multiphase fluids displacement seepage experiment with large viscosity difference in the complex pore structure according to claim 1 , wherein the visualization complex pore model is a cuboid with a rectangular cross section, and the inlet and outlet of the visualization complex pore model are respectively sealed with a first conical joint and a second conical joint, the outlets of the injection pumps are communicated with an inlet of the first conical joint, and an outlet of the second conical joint is communicated with a liquid accommodating component at outside, and the liquid accommodating component is configured to accommodate the liquid flowing out of the visualization complex pore model.

4. The visualization system for the multiphase fluids displacement seepage experiment with large viscosity difference in the complex pore structure according to claim 3 , wherein an outer end of the first conical joint defines ports in one-to-one correspondence with the injection pumps, and an interior of the first conical joint defines channels in one-to-one correspondence with the ports, and the channels are isolated from each other, inner ends of the channels are communicated with the inlet of the visualization complex pore model, and one injection pump is communicated with one of the ports through an independently arranged pipe.

5. The visualization system for the multiphase fluids displacement seepage experiment with large viscosity difference in the complex pore structure according to claim 3 , wherein an inlet pipe segment of the visualization complex pore model is inserted into the first conical joint and the visualization complex pore model and the first conical joint are circumferentially sealed; an outlet pipe segment of the visualization complex pore model is inserted into the second conical joint, and the visualization complex pore model and the second conical joint are circumferentially sealed.

6. The visualization system for the multiphase fluids displacement seepage experiment with large viscosity difference in the complex pore structure according to claim 3 , wherein two ends of an outer circumferential surface of the visualization complex pore model are also formed with mounting bosses, and the mounting bosses are formed with bolt mounting holes for mounting bolts locking to the first conical joint or the second conical joint.

7. A method for a multiphase fluids displacement seepage experiment with large viscosity difference in a complex pore structure, the method specifically comprising:
using a 3D printing device to print a visualization complex pore model, wherein the visualization complex pore model comprises an inlet and an outlet, and an interior of the visualization complex pore model comprises at least two parts of a complex pore structure, and the permeability of each part of the complex pore structure is different;
putting the entire printed visualization complex pore model into an ultrasonic cleaning machine for vibration cleaning;
injecting cleaning liquid into the visualization complex pore model at a predetermined pressure after vibration cleaning, and repeating it several times until support material in the visualization complex pore model is completely removed;
connecting outlets of a first injection pump, a second injection pump and a third injection pump to the inlet of the visualization complex pore model through independent pipes;
injecting a displaced fluid medium into the visualization complex pore model through the first injection pump, and stopping injection of the visualization complex pore model until the displaced fluid medium reaches the outlet of the visualization complex pore model, and moving the entire system comprising the visualization complex pore model and the injection pump to an interior of a vacuum pressure device for vacuuming, and stopping vacuuming until bubbles inside the visualization complex pore model move outside the complex pore structure during a vacuuming process;
taking the entire system out of the vacuum pressure device, turning on the first injection pump to continue injecting the visualization complex pore model with the displaced fluid medium, using gravity and density difference between the displaced fluid medium and the air to control a placement direction of the visualization complex pore model to allow the bubbles to be discharged from the outlet;
injecting a first driving fluid into the visualization complex pore model through the second injection pump, until the first driving fluid flows out of the outlet of the visualization complex pore model; wherein the viscosity of the first driving fluid is lower than the viscosity of the displaced fluid medium;
injecting a second driving fluid into the visualization complex pore model through the third injection pump, until the second driving fluid flows out of the outlet of the visualization complex pore model; wherein the viscosity of the second driving fluid is higher than the viscosity of the displaced fluid medium; and
when the first injection pump, the second injection pump, and

Assignees

• Univ China Mining

Inventors

• Ju Yang
• Zheng Jiangtao
• Chang Wei
• Xi Chaodong

Classifications

• G01N2015/0846

  by use of radiation, e.g. transmitted or reflected light · CPC title

• G01N15/082

  Investigating permeability by forcing a fluid through a sample · CPC title

• G01N2223/419

  computed tomograph · CPC title

• G01N2223/405

  mapping of a material property · CPC title

• G01N2223/401

  image processing · CPC title