Device and method for preparing microbubble dispersion fluid for oil displacement

Abstract

The invention provides a device and method for preparing microbubble dispersion fluid for oil displacement, and relates to the technical field of oil exploitation, the device comprises: a cylinder, the side wall of which is provided with a liquid inlet and an air inlet, and the tail end of which is provided with a bubble discharge port; the stirring unit comprises a stirrer and a stirring assembly connected with the stirrer, and the stirring assembly is arranged in the barrel; the gas-liquid dispersion unit comprises a gas release ring, a threaded rotary vane and a microporous screen which are arranged in the cylinder body, the gas release ring is connected with the gas inlet, and the threaded rotary vane is arranged between the gas release ring and the microporous screen and is used for guiding gas-liquid mixture formed by gas dispersed by the gas release ring and liquid flowing into the cylinder body through the liquid inlet; and gas and liquid are mixed to form high-speed rotational flow. The method adopts the preparation device of the microbubble dispersion fluid for oil displacement, and can simulate the conditions of an offshore platform to realize preparation of microbubble dispersion fluid with different bubble diameters.

Description

Technical Field

[0001] The present invention relates to the technical field of oil extraction, and particularly to a device and method for preparing a microbubble dispersed fluid for oil displacement. Background Art

[0002] A microbubble dispersed fluid refers to a gas-liquid two-phase dispersion system with microbubbles as the dispersed phase and water or surfactant as the continuous phase. The microbubbles have a micron size and belong to the category of foam systems. The microscale characteristics brought by the microbubbles endow it with many properties different from conventional foams, such as a long half-life, a high interfacial ζ potential, high stability, high mass transfer efficiency, pressure increase and solubilization, strong salt, temperature, and oil resistance, etc. In addition, the microbubbles are small in size and have good injectability into the formation. Later, as the formation flowing pressure decreases, the Jamin effect of the microbubbles appears, which can play a good role in deep profile control and displacement in the reservoir.

[0003] Currently, the methods for preparing microbubble dispersed fluids indoors mainly include high-speed stirring, sand-packed tube foaming method, and microfluidic method. The microbubble systems prepared by these methods show good plugging ability and oil displacement effect in indoor physical model displacement experiments. However, the diameter of the microbubbles generated by the high-speed stirring method is not easy to control and has a wide distribution. The microbubble systems prepared by the sand-packed tube foaming method and microfluidic method are only suitable for indoor experimental research and are not applicable to field working conditions. Industrial-grade microbubble preparation devices under normal temperature and pressure (low pressure) are relatively mature and are mainly used in air flotation water purification, environmental protection treatment, etc., and cannot be applied to the reservoir conditions of high temperature and high pressure in offshore oilfields. The existing microbubble dispersed fluid devices for oil fields use a porous membrane dispersion method, and the prepared microbubbles have a large size and a single regulation factor.

[0004] Therefore, there is an urgent need for a device and method for preparing a microbubble dispersed fluid for oil displacement to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a device and method for preparing a microbubble dispersed fluid for oil displacement, which can simulate the preparation of microbubble dispersed fluids for oil displacement under different conditions and the microbubble size is adjustable. It is prepared and injected into the formation online by simulating the conditions of offshore oilfield platforms, with strong practicability, and has certain guiding significance for the technology of applying microbubble dispersed fluids to improve oil recovery in offshore oilfields. The many technical effects that can be produced by the preferred technical solutions among the many technical solutions provided by the present invention are described in detail below.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A device for preparing a microbubble dispersed fluid for oil displacement provided by the present invention includes:

[0008] A cylinder body, an inlet for liquid and an inlet for gas are arranged on the side wall of the cylinder body, and an air outlet is arranged at the end of the cylinder body;

[0009] A stirring unit, comprising a stirrer and a stirring assembly connected to the stirrer, the stirring assembly being disposed inside the cylinder;

[0010] A gas-liquid dispersion unit, comprising a gas release ring, a threaded rotating vane and a microporous screen disposed inside the cylinder, the gas release ring being connected to the air inlet, the threaded rotating vane being disposed between the gas release ring and the microporous screen for guiding the gas-liquid mixture formed by the gas dispersed through the gas release ring and the liquid flowing into the cylinder through the liquid inlet, and causing the gas-liquid mixture to form a high-speed swirl.

[0011] Preferably, the cylinder comprises:

[0012] A preparation main body, wherein the stirring assembly and the gas-liquid dispersion unit are both disposed inside the preparation main body;

[0013] A monitoring main body, one end being connected to the end of the preparation main body, and the other end being provided with the bubble discharge port.

[0014] Preferably, a viewing window is provided on the monitoring main body for observing the preparation of the microbubble-dispersed fluid after passing through the microporous screen.

[0015] Preferably, it further comprises a camera assembly and a terminal device communicatively connected to the camera assembly, the camera assembly being capable of recording the preparation of the microbubble-dispersed fluid through the viewing window, and the terminal device being used for analyzing the microbubble size and distribution state..

[0016] Preferably, it further comprises a temperature-controlled heating belt, the temperature-controlled heating belt being disposed outside the preparation main body.

[0017] Preferably, the air inlet can be connected to a high-pressure gas storage tank;

[0018] The liquid inlet can be connected to a water injection pipeline of an offshore platform;

[0019] The bubble discharge port can be connected to a wellhead pipeline of a water injection well on an offshore platform.

[0020] Preferably, the stirring assembly comprises:

[0021] A stirring shaft, connected to the stirrer;

[0022] Stirring blades, disposed on the stirring shaft.

[0023] Preferably, there are four pairs of the stirring blades, and the two stirring blades in each pair are symmetrically disposed on the stirring shaft, and the included angle between the stirring blade and the axis of the stirring shaft is 10°-20°.

[0024] Preferably, the angle between the stirring paddle and the axis of the stirring shaft is 12°.

[0025] A method for preparing a microbubble-dispersed fluid for oil displacement, using the above-mentioned device for preparing a microbubble-dispersed fluid for oil displacement, includes the following steps:

[0026] Step 1: Turn on the camera assembly and the terminal device, and align the focus of the camera assembly with the viewing window;

[0027] Step 2: Turn on the temperature control heating tape and set the experimental temperature;

[0028] Step 3: Open the liquid inlet, so that the liquid flows in and fills the entire preparation main body, and keep the liquid flowing out from the bubble discharge port at a specified flow rate;

[0029] Step 4: Turn on the mixer and set the stirring component to rotate at a lower speed;

[0030] Step 5: Open the gas inlet, so that the gas enters the preparation main body at a specified flow rate;

[0031] Step 6: Observe and analyze the preparation situation of the microbubble-dispersed fluid through the viewing window, the camera assembly and the terminal device, and control the microbubble size and distribution by adjusting the rotation speed of the mixer and the gas-liquid displacement of the gas inlet and the liquid inlet;

[0032] Step 7: After the experiment is over, first close the gas inlet, then close the mixer and the liquid inlet, and finally close the camera assembly and the terminal device.

[0033] The device for preparing a microbubble-dispersed fluid for oil displacement provided by the present invention includes a cylinder body, a stirring unit and a gas-liquid dispersion unit. The side wall of the cylinder body is provided with a liquid inlet and a gas inlet, the end of the cylinder body is provided with a bubble discharge port, the stirring unit includes a mixer and a stirring component connected to the mixer, the stirring component is arranged in the cylinder body, the gas-liquid dispersion unit includes a gas release ring, a threaded vane and a microporous sieve mesh arranged in the cylinder body, the gas release ring is connected to the gas inlet, the threaded vane is arranged between the gas release ring and the microporous sieve mesh, the gas flows into the cylinder body from the gas inlet, is dispersed by the gas release ring and mixed with the liquid flowing into the cylinder body through the liquid inlet, the gas-liquid mixed fluid forms a high-speed swirl through the diversion of the threaded vane, collides with the high-speed rotating stirring component driven by the mixer, disperses the gas into tiny bubbles and distributes them in the liquid, filters out the bubbles with larger sizes through the microporous sieve mesh, and the prepared microbubble-dispersed fluid flows out from the bubble discharge port. By controlling the gas-liquid stirring and dispersion intensity through the rotation speed of the mixer, the conditions of an offshore platform can be simulated, and the preparation of microbubble-dispersed fluids with different bubble diameters can be realized.

[0034] The method for preparing the microbubble dispersion fluid for enhanced oil recovery provided by the present invention, by using the above-mentioned device for preparing the microbubble dispersion fluid for enhanced oil recovery, can simulate the preparation of the microbubble dispersion fluid under high-pressure conditions, can simulate the preparation of the microbubble dispersion fluid under formation temperature conditions, and can achieve the preparation of the microbubble dispersion fluid with different bubble diameters, can achieve real-time monitoring of the preparation of the microbubble dispersion fluid, can simulate offshore platform conditions, and can prepare the microbubble dispersion fluid online and inject it into the formation. Brief Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 is a schematic structural diagram of an embodiment of the device for preparing the microbubble dispersion fluid for enhanced oil recovery of the present invention;

[0037] Figure 2 is a schematic structural diagram of the shaft support in the device for preparing the microbubble dispersion fluid for enhanced oil recovery of the present invention.

[0038] In the figure: 1, agitator; 2, sealing ring; 3, first bolt; 4, air inlet; 5, liquid inlet; 6, gas release ring; 7, threaded vane; 8, preparation main body; 9, stirring blade; 10, stirring shaft; 11, shaft support; 12, second bolt; 13, micro-porous sieve; 14, visual window; 15, monitoring main body; 16, bubble discharge port; 17, temperature control heating belt; 18, camera assembly; 19, terminal device. Detailed Embodiments

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0041] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Figure 1 is a schematic structural diagram of this embodiment, as Figure 1 shown, this embodiment provides a device for preparing a microbubble dispersion fluid for oil displacement, which includes a cylinder body, a stirring unit, and a gas-liquid dispersion unit.

[0043] Among them, a liquid inlet 5 and a gas inlet 4 are provided on the side wall of the cylinder body, and a bubble discharge port 16 is provided at the end of the cylinder body. The cylinder body in this embodiment adopts a steel pressure-resistant cylinder body, and both the liquid inlet 5 and the gas inlet 4 are made of high-temperature and pressure-resistant materials to simulate the high-temperature and high-pressure conditions of an offshore platform.

[0044] The stirring unit includes a stirrer 1 and a stirring assembly connected to the stirrer 1, and the stirring assembly is arranged inside the cylinder body. The stirrer 1 in this embodiment adopts a magnetic stirrer, and the magnetic stirrer is connected to the cylinder body through a first bolt 3, and the magnetic stirrer and the cylinder body are sealed through a sealing ring 2.

[0045] The gas-liquid dispersion unit includes a gas release ring 6, a threaded vane 7, and a microporous screen 13 arranged inside the cylinder body. Among them, the gas release ring 6 is connected to the gas inlet 4, and the threaded vane 7 is arranged between the gas release ring 6 and the microporous screen 13. The threaded vane 7 in this embodiment is inserted and fixed inside the cylinder body, and is used to guide the gas-liquid mixture formed by the gas dispersed through the gas release ring 6 and the liquid flowing into the cylinder body through the liquid inlet 5, and make the gas-liquid mixture form a high-speed swirl, which can simulate the preparation of a microbubble dispersion fluid with different bubble diameters under high-pressure conditions, and can solve the problems that the existing industrial microbubble preparation device cannot simulate the preparation of a microbubble dispersion fluid under high-pressure conditions, and the microbubble size is large and the control factors are single.

[0046] As an alternative embodiment, the cylinder body in this embodiment includes a preparation main body 8 and a monitoring main body 15, and the preparation main body 8 and the monitoring main body 15 are connected by a second bolt 12. Among them, the stirring assembly and the gas-liquid dispersion unit are both arranged in the preparation main body 8; the monitoring main body 15 adopts a steel frame, one end is connected to the end of the preparation main body 8, and the other end is provided with a bubble discharge port 16.

[0047] Specifically, a viewing window 14 is arranged on the monitoring main body in this embodiment, and the viewing window 14 is fixed in the steel frame for observing the preparation situation of the microbubble-dispersed fluid after passing through the microporous sieve mesh 13.

[0048] As an alternative embodiment, this microbubble-dispersed fluid preparation device for enhanced oil recovery further includes a camera assembly 18 and a terminal device 19 communicatively connected to the camera assembly 18, and the camera assembly 18 can record the preparation situation of the microbubble-dispersed fluid through the viewing window 14.

[0049] The camera assembly 18 in this embodiment adopts a camera, which can take pictures and videos, and the terminal device 19 adopts a computer. During use, observe the preparation situation of the microbubble-dispersed fluid after passing through the microporous sieve mesh 13 through the viewing window 14, record the pictures by the camera assembly 18, and analyze the microbubble size and distribution state through the terminal device 19, so as to realize the real-time monitoring of the preparation situation of the microbubble-dispersed fluid; it can solve the problem that the existing industrial-grade microbubble preparation device cannot realize the online monitoring of the online preparation situation of the microbubble-dispersed fluid.

[0050] As an alternative embodiment, this microbubble-dispersed fluid preparation device for enhanced oil recovery further includes a temperature-controlled heating belt 17. The temperature-controlled heating belt 17 can be set at different temperatures to provide heating and maintain a constant temperature environment for the fluid inside the preparation main body 8, and can simulate the preparation of microbubble-dispersed fluid under different formation temperature conditions.

[0051] Specifically, the temperature-controlled heating belt 17 in this embodiment is arranged on the outer side of the preparation main body 8 for simulating the preparation of microbubble-dispersed fluid under formation temperature conditions, and solves the problem that the existing industrial-grade microbubble preparation device cannot simulate the preparation of microbubble-dispersed fluid under high-temperature conditions.

[0052] As an alternative embodiment, the air inlet 4 can be connected to a high-pressure gas storage tank; the liquid inlet 5 can be connected to the water injection pipeline of an offshore platform; the bubble discharge port 16 can be connected to the wellhead pipeline of an injection well on the offshore platform, so as to realize the on-line preparation and injection of microbubble-dispersed fluid for enhanced oil recovery into the formation, and can solve the problems of large floor area of the existing industrial-grade microbubble preparation device, inability to connect to the water injection process of the offshore platform, and non-compliance with the injection process requirements of offshore oilfields.

[0053] As an alternative embodiment, the stirring assembly in this embodiment includes a stirring shaft 10 and stirring blades 9. Optionally, as Figure 2As shown in the figure, it also includes a shaft support 11. Among them, the mixer 1 is connected to the front end of the stirring shaft 10; the end of the stirring shaft 10 is placed at the center of the shaft support 11, the stirring blades 9 are fixed on the stirring shaft 10, and the mixer 1 drives the stirring shaft 10 and the stirring blades 9 to rotate.

[0054] In this embodiment, there are four pairs of stirring blades 9. The two stirring blades 9 in each pair are fixed on the stirring shaft 10 symmetrically, and the angle between the stirring blade 9 and the axis of the stirring shaft 10 is 10° - 20°.

[0055] Preferably, the angle between the stirring blade 9 and the axis of the stirring shaft 10 is 12°. The adjacent two pairs of stirring blades 9 are arranged at 90°.

[0056] During use, by adjusting the rotation speed of the mixer 1, the stirring intensity of the stirring blade 9 can be controlled to simulate different gas-liquid dispersion degrees, so as to realize the preparation of microbubble-dispersed fluids with different bubble diameters.

[0057] For this microbubble-dispersed fluid preparation device for enhanced oil recovery, gas flows into the cylinder body from the air inlet 4, is dispersed by the gas release ring 6 and mixed with the liquid flowing into the cylinder body through the liquid inlet 5. The gas-liquid mixed fluid forms a high-speed swirl through the diversion of the threaded vane 7, collides with the high-speed rotating stirring blade 9 driven by the mixer 1, disperses the gas into tiny bubbles and distributes them in the liquid, filters out the larger-sized bubbles through the microporous sieve 13 to form a microbubble-dispersed fluid, and the prepared microbubble-dispersed fluid flows out from the bubble discharge port 16. By controlling the gas-liquid stirring and dispersion intensity through the rotation speed of the mixer 1, the preparation of microbubble-dispersed fluids with different bubble diameters can be realized. It can simulate the conditions of an offshore platform, prepare microbubble-dispersed fluids for enhanced oil recovery with different bubble diameters, monitor the size and distribution state of microbubbles in the microbubble-dispersed fluid in real time through the viewing window 14, and regulate the internal fluid temperature of the steel pressure-resistant cylinder body in real time through the temperature control heating belt 17. It can simulate the actual situation under different temperature and pressure conditions of an offshore platform, prepare microbubble-dispersed fluids for enhanced oil recovery online and monitor the preparation situation in real time, which has certain guiding significance for the technology of applying microbubble-dispersed fluids to improve oil recovery in offshore oilfields.

[0058] This embodiment also provides a method for preparing a microbubble-dispersed fluid for enhanced oil recovery, using the above-mentioned microbubble-dispersed fluid preparation device for enhanced oil recovery, which includes the following steps:

[0059] Step 1: Turn on the camera assembly 18 and the terminal device 19, and align the focus of the camera assembly 18 with the viewing window 14;

[0060] Step 2: Turn on the temperature control heating belt 17 and set the required experimental temperature;

[0061] Step 3: Open the liquid inlet 5 to allow the liquid to flow in and fill the entire preparation main body, and keep the liquid flowing out from the bubble discharge port 16 at a certain flow rate;

[0062] Step 4: Turn on the blender 1 and set the stirring paddle 9 of the stirring assembly to rotate at a low speed; wherein, the low speed refers to the lowest gear speed of the blender 1.

[0063] Step 5: Open the air inlet 4 to allow gas to enter the preparation main body at a specified flow rate;

[0064] Step 6: Observe and analyze the preparation of the microbubble dispersion fluid through the visual window 14, the camera assembly 18 and the terminal device 19, and control the microbubble size and distribution by adjusting the rotation speed of the blender 1 and the gas-liquid displacement of the air inlet 4 and the liquid inlet 5;

[0065] Step 7: After the experiment, first close the air inlet 4, then close the blender 1 and the liquid inlet 5, and finally close the camera assembly 18 and the terminal device 19.

[0066] By adopting this method for preparing the microbubble dispersion fluid for enhanced oil recovery, it is possible to simulate the preparation of the microbubble dispersion fluid under high-pressure conditions, simulate the preparation of the microbubble dispersion fluid under formation temperature conditions, and can achieve the preparation of the microbubble dispersion fluid with different bubble diameters, can achieve real-time monitoring of the preparation of the microbubble dispersion fluid, can simulate offshore platform conditions, and on-line prepare the microbubble dispersion fluid and inject it into the formation.

[0067] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A device for preparing microbubble dispersion fluid for oil displacement, characterized in that: include: A cylinder, wherein a liquid inlet and an air inlet are arranged on the side wall of the cylinder, and a bubble discharge port is arranged at the end of the cylinder; A stirring unit, comprising a stirrer and a stirring assembly connected to the stirrer, wherein the stirring assembly is disposed in the cylinder; The gas-liquid dispersion unit includes a gas release ring, a threaded vane and a microporous screen arranged in the cylinder body, the gas release ring is connected to the gas inlet, and the threaded vane is arranged between the gas release ring and the microporous screen to guide the gas dispersed by the gas release ring and the liquid flowing into the cylinder body through the liquid inlet to form a gas-liquid mixture, and make the gas-liquid mixture form a high-speed vortex.

2. A device for preparing microbubble dispersion fluid for oil displacement according to claim 1, characterized in that: The cylinder comprises: A preparation body, wherein the stirring assembly and the gas-liquid dispersion unit are both arranged in the preparation body; The monitoring body has one end connected to the end of the preparation body and the other end provided with the bubble discharge port.

3. A device for preparing microbubble dispersion fluid for oil displacement according to claim 2, characterized in that: A visual window is provided on the monitoring body to observe the preparation of the microbubble dispersion fluid after passing through the microporous screen.

4. A device for preparing microbubble dispersion fluid for oil displacement according to claim 3, characterized in that: It also includes a camera component and a terminal device that is communicatively connected to the camera component. The camera component can record the preparation of the microbubble dispersion fluid through the visual window, and the terminal device is used to analyze the size and distribution state of the microbubbles.

5. A device for preparing microbubble dispersion fluid for oil displacement according to claim 4, characterized in that: It also includes a temperature-control heating belt, which is arranged on the outside of the preparation body.

6. A device for preparing a microbubble dispersion fluid for oil displacement according to any one of claims 1 to 5, characterized in that: The air inlet can be connected to a high-pressure gas storage tank; The liquid inlet can be connected to the water injection pipeline of the offshore platform; The bubble discharge port can be connected to the wellhead pipeline of the offshore platform water injection well.

7. A device for preparing a microbubble dispersion fluid for oil displacement according to any one of claims 1 to 5, characterized in that: The stirring assembly comprises: A stirring shaft connected to the stirrer; The stirring blade is arranged on the stirring shaft.

8. The device for preparing a microbubble dispersion fluid for oil displacement according to claim 7, characterized in that: The stirring blades include four pairs, and the two stirring blades in each pair are symmetrically arranged on the stirring shaft, and the angle between the stirring blades and the axis of the stirring shaft is 10°-20°.

9. The device for preparing a microbubble dispersion fluid for oil displacement according to claim 8, characterized in that: The angle between the stirring blade and the axis of the stirring shaft is 12°.

10. A method for preparing a microbubble dispersed fluid for oil displacement, characterized in that: The device for preparing microbubble dispersion fluid for oil displacement according to any one of claims 5 to 9 is characterized in that it comprises the following steps: Step 1: Open the camera assembly and the terminal device, and focus the camera assembly on the visual window; Step 2: Turn on the temperature-controlled heating belt and set the experimental temperature; Step 3: Open the liquid inlet to allow the liquid to flow into and fill the entire preparation body, and keep the liquid flowing out of the bubble outlet at a specified flow rate; Step 4: Turn on the mixer and set the stirring assembly to rotate at a lower speed; Step 5: Open the gas inlet to allow gas to enter the preparation body at a specified flow rate; Step 6: Observe and analyze the preparation of the microbubble dispersion fluid through the visual window, the camera assembly and the terminal device, and control the size and distribution of the microbubbles by adjusting the rotation speed of the mixer and the gas-liquid displacement of the gas inlet and the liquid inlet; Step 7: After the experiment is over, first close the air inlet, then close the blender and the liquid inlet, and finally close the camera assembly and the terminal device.

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