Viscosity reduction device and method for chemical flooding well

Abstract

The invention belongs to the technical field of oil field oil extraction, and discloses a viscosity reduction device and method for a chemical flooding well. Comprising a mechanical shearing viscosity reduction part and a strong magnetic viscosity reduction part, and the mechanical shearing viscosity reduction part comprises an oil pipe coupling, a short section, an upper end overflowing pipe, a vertical rotating impeller, an upper supporting frame, a middle overflowing pipe, an upper pore plate, a lower pore plate, a horizontal rotating impeller set and a lower end overflowing pipe. The strong magnetic viscosity reduction component comprises a connecting coupling, an outer pipe, a strong magnetic alloy set and an inner pipe. The device is simple in process, novel in structural design and high in working reliability, and meets test and site construction requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field production, and particularly relates to a viscosity reduction device and method for a chemical flooding oil well. Background Art

[0002] When using polymer flooding for oil recovery, problems such as polymer formation in production wells and increased well fluid viscosity, leading to increased difficulty in lifting, are common in the later stages. Taking Block Jin 16 of the Liaohe Oilfield as an example, there are 143 chemical flooding production wells, all of which are plagued by polymer formation in the production well fluids. Polymer concentrations in the produced fluids can reach over 500 ppm, leading to a sharp increase in well fluid viscosity. This can lead to the following three problems:

[0003] (1) Pumps frequently get stuck in machine-produced wells, causing rod string tripping and motor burnout in some screw pump production wells. The average pump inspection cycle is only 347 days (733 days for Liaohe Oilfield Company).

[0004] (2) The rod column is difficult to descend, resulting in serious eccentric wear and reduced pump efficiency. Pump inspections due to eccentric wear account for 40% of the total number of pump inspections.

[0005] (3) Conventional chemical viscosity reduction measures are expensive and the implementation process is complex.

[0006] Therefore, a simple and reliable process and method is urgently needed to achieve low-cost and effective viscosity reduction of polymer-containing well fluids, create favorable conditions for lifting the pumping well, reduce the running resistance of the rod string, and avoid unnecessary pump inspections and maintenance operations of the oil well. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, the present invention provides a device and method for reducing viscosity in chemical flooding wells. This simple, low-cost device and method can achieve viscosity reduction in polymer-containing well fluids. It is used to physically reduce the viscosity of polymer-containing well fluids in chemical flooding wells before they enter the pump. The device only needs to be installed below the oil well pump, making it simple to operate and convenient to install.

[0008] The above-mentioned objective of the present invention is achieved through the following technical solution: a viscosity reduction device for chemical flooding oil wells, comprising a mechanical shear viscosity reduction component and a strong magnetic viscosity reduction component. The mechanical shear viscosity reduction component includes a tubing coupling, a short section, an upper flow tube, a vertically rotating impeller, an upper support frame, an intermediate flow tube, upper and lower orifice plates, a horizontally rotating impeller assembly, and a lower flow tube. The strong magnetic viscosity reduction component includes a connecting coupling, an outer tube, a strong magnetic alloy assembly, and an inner tube. The strong magnetic viscosity reduction component is directly connected to the upper portion of the mechanical shear viscosity reduction component via threads. The tubing coupling is directly connected to the lower end of the outer tube, the short section is threadedly connected to the lower end of the tubing coupling, the upper flow tube is threadedly connected to the lower end of the short section, the vertically rotating impeller is welded to the middle position of the upper support frame, the upper support frame is welded to the internal step of the intermediate flow tube, the intermediate flow tube is threadedly connected to the upper flow tube and the lower end to the upper orifice plate, the upper orifice plate is threadedly connected to the lower orifice plate, the horizontally rotating impeller assembly rotates around the central axis at the center circular holes of the upper and lower orifice plates, the lower flow tube is threadedly connected to the lower orifice plate, and the bottom is threaded to allow for further connection to the tubing. The connecting coupling is directly connected to the tubing, the outer tube is threadedly connected to the lower end of the connecting coupling, the inner tube is welded to the inner wall of the outer tube, and the strong magnetic alloy group is regularly placed in the annulus space between the outer and inner tubes.

[0009] Furthermore, the interior of the lower end flow tube is in a semi-bell-mouth shape, and the inner side is a smooth arc surface.

[0010] Furthermore, the interior of the upper orifice plate and the lower orifice plate are laterally designed to be porous.

[0011] Furthermore, the horizontal rotating impeller group is divided into three groups, and the maximum outer diameter of each group is different.

[0012] A further preferred embodiment of the present invention is that each of the three groups of horizontal rotating impellers is divided into 5 blades, which are welded to the central axis at an angle of 45 degrees, and the vertical rotating impeller has 5 larger arc-shaped blades welded to the upper support frame.

[0013] Furthermore, the matrix material of the ferromagnetic alloy group is neodymium iron boron.

[0014] In a further preferred embodiment of the present invention, the ferromagnetic alloy group is cast using a nano-molding process to form a microcrystalline giant magnetic alloy with an annular structure. There are 60 groups in total, which are arranged in an orderly manner in the annular space between the outer tube and the inner tube to form a regional ferromagnetic space as a whole.

[0015] Another object of the present invention is to provide a method for reducing the viscosity of chemically flooded oil wells, which is carried out using the above-mentioned chemically flooded oil well viscosity reduction device. The specific steps are: during oil well production, the chemically flooded oil well viscosity reduction device is directly connected to the bottom of the oil pump. The well fluid flows through the device before entering the pump. Through mechanical shear stress, oscillating stirring and strong magnetic field, the viscosity of the polymer-containing well fluid is significantly reduced.

[0016] Compared to existing technologies, the present invention offers the following advantages: A device and method for reducing viscosity in chemical flooding oil wells primarily addresses the difficulty in lifting oil produced by chemical flooding due to increased viscosity caused by polymer content. Through mechanical shearing and strong magnetic viscosity reduction, the invention effectively reduces the viscosity of polymer-containing fluids, creating favorable conditions for oil well lifting, reducing the risk of rod string wear, conserving pumping unit energy, and avoiding unnecessary pump inspections and maintenance. The invention boasts a simple process, novel structural design, and high operational reliability, meeting the requirements of both testing and field operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a schematic structural diagram of the mechanical shear viscosity reduction component of the chemical flooding oil well viscosity reduction device of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the strong magnetic viscosity reduction component of the viscosity reduction device for chemical flooding oil wells of the present invention.

[0020] In the figure, 1. Oil pipe coupling; 2. Short section; 3. Upper flow tube; 4. Vertically rotating impeller; 5. Upper support frame; 6. Middle flow tube; 7. Upper orifice plate; 8. Lower orifice plate; 9. Horizontally rotating impeller assembly; 10. Lower flow tube; 2-1. Connecting coupling; 2-2. Outer tube; 2-3. Strong magnetic alloy assembly; 2-4. Inner tube. DETAILED DESCRIPTION

[0021] The present invention is described in detail below by specific examples, but the scope of protection of the present invention is not limited. Unless otherwise specified, the experimental methods adopted in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0022] Example 1

[0023] A chemical flooding oil well viscosity reduction device and method (attached Figure 1 、 2), primarily composed of a mechanical shear viscosity reduction component and a strong magnetic viscosity reduction component. The mechanical shear viscosity reduction component primarily includes 1. an oil pipe coupling, 2. a short joint, 3. an upper flow tube, 4. a vertically rotating impeller, 5. an upper support frame, 6. an intermediate flow tube, 7. an upper orifice plate, 8. a lower orifice plate, 9. a horizontally rotating impeller assembly, and 10. The strong magnetic viscosity reduction component primarily includes 2.1. a connecting coupling, 2.2. an outer tube, 2.3. a strong magnetic alloy assembly, and 2.4. an inner tube. The strong magnetic viscosity reduction component is directly connected to the top of the mechanical shear viscosity reduction component via threads. 1. The oil pipe coupling is directly connected to the lower end of the 2-2 outer pipe, 2. The short section is connected to the bottom of the oil pipe coupling by threads, 3. The upper flow pipe is connected to the bottom of the 2 short sections by threads, 4. The vertical rotating impeller is welded to the middle position of the 5 upper support frame, 5. The upper support frame is welded to the internal step of the 6 intermediate flow pipe, 6. The intermediate flow pipe is connected to the upper flow pipe 3 by threads and is connected to the upper orifice plate 7 by threads, the upper orifice plate 7 is connected to the lower orifice plate 8 by threads, 9. The horizontally rotating impeller group rotates at the central circular holes of the upper orifice plate 7 and the lower orifice plate 8 through the central axis, 10. The lower flow pipe is connected to the bottom of the lower orifice plate 8 by threads, and the bottom is threaded, which can continue to connect the oil pipe. The 2-1 connecting coupling is directly connected to the oil pipe, the 2-2 outer pipe is connected to the lower end of the 2-1 connecting coupling through threads, the 2-4 inner pipe is welded to the inner wall of the 2-2 outer pipe, and the 2-3 strong magnetic alloy group is regularly placed in the annular space between the 2-2 outer pipe and the 2-4 inner pipe.

[0024] During oil well production, the device of the present invention is directly connected below the oil well pump. The well fluid flows through the device before entering the pump. Through mechanical shear stress, oscillatory stirring, and the action of a strong magnetic field, the viscosity of the polymer-containing well fluid is significantly reduced, creating favorable conditions for oil well lifting, significantly improving lifting pump efficiency, reducing rod string operating resistance, and avoiding unnecessary pump inspections and maintenance operations, resulting in greater economic and social benefits. This tubing string is suitable for chemical flooding production wells in oil fields.

[0025] Example 2

[0026] Attachment Figure 1 This is a schematic diagram of the structure of the mechanical shear viscosity reduction component, which mainly includes an oil pipe coupling 1, a short section 2, an upper flow pipe 3, a vertical rotating impeller 4, an upper support frame 5, an intermediate flow pipe 6, an upper orifice plate 7, a lower orifice plate 8, a horizontally rotating impeller group 9, and a lower flow pipe 10.

[0027] Attachment Figure 2 This is a structural diagram of a strong magnetic viscosity reduction component, which mainly includes a connecting coupling 2-1, an outer tube 2-2, a strong magnetic alloy group 2-3, and an inner tube 2-4.

[0028] like Figure 1As shown, the interior of the lower flow tube 10 is a semi-bell-mouth shape, and the inner side is a smooth arc surface, forming a sudden diameter-changing channel. The interior of the upper orifice plate 7 and the lower orifice plate 8 is designed to be porous in the horizontal direction. The horizontal rotating impeller group 9 is divided into three groups, and the maximum outer diameter of each group is different. At the same time, each group is divided into 5 blades, which are welded to the central axis at an angle of 45 degrees. The vertical rotating impeller 4 has 5 larger arc-shaped blades and is welded to the upper support frame 5. Both the horizontal rotating impeller group 9 and the vertical rotating impeller 4 can rotate when the fluid passes through. The interior of the middle flow tube 6 and the upper flow tube 3 are designed to be reduced in diameter.

[0029] like Figure 2 As shown, the strong magnetic alloy group 2-3 uses neodymium iron boron as the base material and is cast using a nano-molding process to form a microcrystalline giant magnetic alloy with a ring structure. There are 60 groups in total, which are arranged in an orderly manner and placed in the ring space between the outer tube 2-2 and the inner tube 2-4, forming a regional strong magnetic space as a whole, and the magnetic field strength can reach more than 1300mT.

[0030] During oil well production, mechanical shear viscosity reduction components and strong magnetic viscosity reduction components are sequentially lowered. The wellbore fluid first passes through the mechanical shear viscosity reduction components before entering the oil well pump. When flowing through the sudden variable diameter flow channel, a pressure difference is formed before and after, thereby pulling the polymer molecular chains to break them; then the fluid passes through the horizontal rotating impeller group 9. Driven by the fluid flow rate, the impeller group rotates, causing oscillation and stirring of the fluid. At the same time, the upper and lower orifice plates 7 and 8 above and below the impeller group can form a forced mechanical shear effect on the fluid through the porous structure; when the fluid at the upper end flows through the vertical rotating impeller 4, it also rotates under the action of the fluid flow rate, and is oscillated and stirred again, thereby causing the polymer-containing fluid to change from a grid structure to a supramolecular aggregate morphology under the overall action, the "entanglement" structure between molecules fails, the long molecular chains break, and the viscoelasticity decreases. When the fluid after oscillation and shearing enters the strong magnetic viscosity reduction component, it continues to be affected by the annular strong magnetic field. Under the action of the magnetic field energy, the polymer fluid medium is subjected to the stress generated by the magnetic field, and the polymer molecules are forced to be pulled and arranged. The pulling of the molecules increases the distance between them, further destroying their original shape and causing the viscoelasticity to further decrease.

[0031] The above-described embodiments are only preferred embodiments of the present invention, and are not intended to be all feasible embodiments of the present invention. Any obvious modifications made by a person skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A viscosity reduction device for chemical flooding oil wells, characterized in that: The invention is composed of a mechanical shear viscosity reduction component and a strong magnetic viscosity reduction component. The mechanical shear viscosity reduction component comprises an oil pipe coupling (1), a short section (2), an upper flow pipe (3), a vertical rotating impeller (4), an upper support frame (5), an intermediate flow pipe (6), an upper orifice plate (7), a lower orifice plate (8), a horizontal rotating impeller group (9), and a lower flow pipe (10); the strong magnetic viscosity reduction component comprises a connecting coupling (2-1), an outer pipe (2-2), a strong magnetic alloy group (2-3), and an inner pipe (2-4); wherein the strong magnetic viscosity reduction component is directly connected to the upper part of the mechanical shear viscosity reduction component through a thread; the oil pipe coupling (1) is directly connected to the lower end of the outer pipe (2-2), the short section (2) is connected to the lower part of the oil pipe coupling (1) through a thread, the upper flow pipe (3) is connected to the lower part of the short section (2) through a thread, and the vertical rotating impeller (4) is welded to the upper support frame. (5) In the middle position, the upper support frame (5) is welded to the inner step of the middle flow pipe (6), the middle flow pipe (6) is connected to the upper flow pipe (3) through a thread, and is connected to the upper orifice plate (7) through a thread, the upper orifice plate (7) is connected to the lower orifice plate (8) through a thread, the horizontal rotating impeller group (9) rotates at the center circular hole of the upper orifice plate (7) and the lower orifice plate (8) through the central axis, the lower flow pipe (10) is connected to the bottom of the lower orifice plate (8) through a thread, and the bottom is designed with a thread, which can continue to connect the oil pipe; the connecting collar (2-1) is directly connected to the oil pipe, the outer pipe (2-2) is connected to the lower end of the connecting collar (2-1) through a thread, the inner pipe (2-4) is welded to the inner wall of the outer pipe (2-2), and the strong magnetic alloy group (2-3) is regularly placed in the annular space between the outer pipe (2-2) and the inner pipe (2-4).

2. The viscosity reduction device for chemical flooding oil wells according to claim 1, characterized in that: The interior of the lower end flow tube (10) is in a semi-bell-mouth shape, and the inner side is a smooth arc surface.

3. The viscosity reduction device for chemical flooding oil wells according to claim 1, characterized in that: The interiors of the upper orifice plate (7) and the lower orifice plate (8) are laterally designed to be porous.

4. The viscosity reduction device for chemical flooding oil wells according to claim 1, characterized in that: The horizontal rotating impeller groups (9) are divided into three groups, and the maximum outer diameter of each group is different.

5. The viscosity reduction device for chemical flooding oil wells according to claim 4, characterized in that: Each of the three groups of horizontal rotating impellers (9) is divided into five blades, which are welded to the central axis at an angle of 45 degrees. The vertical rotating impeller (4) has five large arc-shaped blades which are welded to the upper support frame (5).

6. The viscosity reduction device for chemical flooding oil wells according to claim 1, characterized in that: The matrix material of the ferromagnetic alloy group (2-3) is neodymium iron boron.

7. The viscosity reduction device for chemical flooding oil wells according to claim 6, characterized in that: The ferromagnetic alloy group (2-3) is cast into a microcrystalline giant magnetic alloy with a ring structure by using a nano-molding process. There are 60 groups in total, which are arranged in an orderly manner in the ring space of the outer tube (2-2) and the inner tube (2-4), forming a regional ferromagnetic space as a whole.

8. A method for reducing viscosity of a chemical flooding oil well, characterized in that: The chemical flooding oil well viscosity reduction device according to claim 1 is used for the treatment, and the specific steps are as follows: during oil well production, the chemical flooding oil well viscosity reduction device is directly connected to the bottom of the oil pump, and the well fluid flows through the device before entering the pump. Through mechanical shear stress, oscillation stirring and strong magnetic field, the viscosity of the polymer-containing well fluid is greatly reduced.

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