Feeding accelerator of drilling fluid high-speed centrifugal machine

Abstract

The invention discloses a feeding accelerator of a drilling fluid high-speed centrifugal machine. An inner barrel is arranged in a rotary drum, spiral blades are arranged on the outer circumference of the inner barrel, radial liquid flow holes are formed in the inner barrel, an accelerator is installed in the inner barrel, a flow guide cone is arranged along the axis of the accelerator, the outer contour of the accelerator is composed of paddles arranged at intervals, and the flow guide cone is located at the tail end of the accelerator and arranged in the direction opposite to the liquid flow direction. The slurry entering the inner cylinder and axially flowing is converted into radial flowing, and is discharged to an annular space between the inner cylinder and the rotary drum through the radial liquid flow holes; the outlet end of the liquid inlet pipe is located in the accelerator. The spiral conveyor has the advantages that the structural design is reasonable, the paddle pushes slurry to flow in the annular space of the spiral conveyor in order in a pressurized mode, and the slurry in the inner cavity of the spiral conveyor is discharged in an accelerated mode; the flow of the liquid outlet of the spiral conveyor is stable, solid-phase particles are accelerated to settle, and the separation efficiency of the centrifugal machine is effectively improved.

Description

Technical Field

[0001] The invention relates to a high-speed centrifuge for drilling fluid, in particular to a feeding accelerator for the high-speed centrifuge for drilling fluid, and belongs to the technical field of oil and gas exploration and development. Background Art

[0002] The centrifuge is a key equipment in the drilling solids control system. The solids separated are generally 2 to 5 μm in size. When the two-stage solids control process of "vibrating screen + centrifuge" is adopted, the processing capacity of the centrifuge needs to be greater than 40m 3 / h, the solid phase separation particle size reaches 2-30μm. In drilling and well repair engineering operations, the 10,000-meter ultra-deep well and large-reach well drilling technology puts forward new demands on solid control and purification equipment. Large-displacement, high-speed centrifuges are the basis for achieving solid control and purification. Large-displacement, high-speed, and intelligent centrifuges are their development trends.

[0003] At present, the centrifuge adopts a liquid supply pump to supply liquid. The mud enters the centrifuge screw conveyor cavity through the liquid inlet pipe. The rotating screw conveyor is provided with a radial discharge port. The mud is accelerated by the rotation of the screw conveyor and thrown into the annulus between the screw conveyor and the drum through the discharge port. The high-speed rotation of the drum accelerates the separation of the mud, forming a solid-liquid two-phase liquid pool in the drum. The screw conveyor pushes the drier solid phase to the slag discharge port of the small diameter area of ​​the drum for discharge, and the liquid phase is discharged through the discharge port of the large diameter area of ​​the drum.

[0004] The liquid flow rate of mud entering the screw conveyor mainly depends on the displacement of the liquid supply pump. The rotating screw conveyor changes the direction of the liquid flow and accelerates the mud to be thrown out. When the liquid supply pump supplies a large amount of liquid, the inner cavity of the screw conveyor is filled and a turbulent area is generated. Since the mud in the inner cavity of the screw conveyor cannot enter the annulus between the screw conveyor and the drum in time, the mud will overflow at the inlet of the liquid inlet pipe. When the mud is discharged through the discharge port of the screw conveyor, the flow rate is unstable, which ultimately affects the separation efficiency. Summary of the invention

[0005] In order to overcome the shortcomings that mud in the inner cavity of the existing screw conveyor cannot enter the annulus between the screw conveyor and the drum in time, mud overflows at the inlet of the liquid inlet pipe, and the flow rate of mud is unstable when it is discharged through the liquid discharge port of the screw conveyor, which ultimately affects the separation efficiency, the present invention provides a feeding accelerator for a drilling fluid high-speed centrifuge.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a feeding accelerator of a drilling fluid high-speed centrifuge, including a screw conveyor, an inner cylinder arranged in a rotating drum, spiral blades arranged on the outer circumference of the inner cylinder, radial liquid flow holes arranged in the inner cylinder, an accelerator installed in the inner cylinder, a guide cone arranged along the axis of the accelerator, the outer contour of the accelerator is composed of blades arranged at intervals, the guide cone is located at the end of the accelerator and is arranged in the opposite direction of the liquid flow, the mud entering the inner cylinder axial flow is converted into radial flow, and discharged to the annulus between the inner cylinder and the rotating drum through the radial liquid flow holes; the outlet end of the liquid inlet pipe is located in the accelerator.

[0007] The outer contour of the accelerator is composed of more than two blades; one end of the blade is connected to the liquid inlet end fixing seat of the accelerator, and the other end is connected to the end fixing seat of the accelerator. The surface of the blade is a spiral surface formed by a composite of double axial curves.

[0008] Furthermore, the biaxial composite curve of the blade cross section is formed by continuous rotation around the Y-axis and the Z-axis.

[0009] Furthermore, the biaxial composite curve of the blade cross section continuously rotates around the Y-axis and the Z-axis at an angle of 10 to 20°.

[0010] Furthermore, the two or more blades are evenly distributed along the circumference of the accelerator.

[0011] The guide cone of the accelerator is arranged on the inner side of the terminal fixing seat, and the cone body of the guide cone is arranged along the axis of the accelerator.

[0012] The guide cone includes more than one section of cones; and there is a smooth transition between more than two sections of cones.

[0013] Furthermore, the length of the guide cone is 2 / 5 to 1 / 2 of the length of the blade.

[0014] The radial liquid flow holes on the inner cylinder are arranged close to the liquid inlet end fixing seat of the accelerator.

[0015] A wear-resistant sleeve is fixedly installed on the outlet end of the liquid inlet pipe.

[0016] The beneficial effects of the present invention are that the structural design is reasonable, the blades push the mud to flow in the annulus of the screw conveyor in an orderly pressurized manner, and the mud in the inner cavity of the screw conveyor is discharged faster; the flow rate of the screw conveyor discharge port is stable, the solid phase particles are accelerated to settle, and the separation efficiency of the centrifuge is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an axonometric view of the feeding accelerator of the present invention.

[0018] Figure 2 It is a structural schematic diagram of the feeding accelerator of the present invention.

[0019] Figure 3 yes Figure 2 BB cross-sectional view.

[0020] Figure 4 It is a structural schematic diagram of the working state of the feeding accelerator of the drilling fluid high-speed centrifuge of the present invention.

[0021] In the figure: 1. end fixing seat, 2. guide cone, 3. blade, 4. liquid inlet end fixing seat, 5. bolt, 6. radial mounting hole, 7. positioning screw, 8. sealing ring, 9. positioning hole, 10. radial liquid flow hole, 11. accelerator, 12. screw conveyor, 13. wear-resistant sleeve, 14. liquid inlet pipe, 15. drum, 16. inner cylinder, 17. spiral blade. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, those skilled in the art should be aware that the present invention is not limited to the specific embodiments listed, and all embodiments should be included in the protection scope of the present invention as long as they conform to the spirit of the present invention.

[0023] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "left", "right", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing or simplifying the description of the present invention, 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 cannot be understood as a limitation on the present invention.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connection", and "seal" should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection, a direct connection, an indirect connection, or an integral connection; it can be a mechanical connection, an indirect connection through an intermediate medium, or a communication between the two components. The seal can be an oil seal, a packing seal, or other forms of seals. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] See attached Figure 4 The present invention provides a feeding accelerator for a drilling fluid high-speed centrifuge, comprising a screw conveyor 12 , an inner cylinder 16 of which is disposed in a rotating drum 15 , a spiral blade 17 is disposed on the outer circumference of the inner cylinder 16 , a radial liquid flow hole 10 is disposed in the inner cylinder 16 , and an accelerator 11 is fixedly installed in the inner cylinder 16 .

[0026] The accelerator 11 includes a guide cone 2, a paddle 3, a liquid inlet end fixing seat 4, and an end fixing seat 1. The guide cone 2 is arranged along the axis of the accelerator 11. The outer contour between the liquid inlet end fixing seat 4 and the end fixing seat 1 of the accelerator 11 is formed by the paddle 3. The guide cone 2 is located at the end of the accelerator 11 and is arranged opposite to the liquid flow direction. As the inner cylinder 16 rotates at a high speed, the accelerator 11 converts the axial flow of the mud entering the inner cylinder 16 into radial flow, and discharges it to the annulus between the inner cylinder 16 and the drum 15 through the radial liquid flow holes 10, and the solid phase of the mud is discharged by the screw conveyor 12; the outlet end of the liquid inlet pipe 14 is located in the accelerator 11.

[0027] See attached Figure 1 , 2 The outer contour of the accelerator 11 is composed of more than two blades 3; one end of the blade 3 is connected to the liquid inlet end fixing seat 4 of the accelerator 11, and the other end is connected to the end fixing seat 1 of the accelerator 11. The surface of the blade 3 is a spiral surface formed by a double axial curve.

[0028] Furthermore, the biaxial composite curve of the cross section of the blade 3 is formed by continuous rotation around the Y-axis and the Z-axis; the biaxial composite curve of the cross section of the blade 3 is continuously rotated around the Y-axis and the Z-axis by an angle of 10 to 20°. Preferably, the biaxial composite curve of the cross section of the blade 3 is continuously rotated around the Y-axis and the Z-axis by an angle of 14 to 15°.

[0029] Furthermore, the two or more blades 3 are evenly distributed along the circumference of the accelerator 11. Preferably, the number of blades 3 is 4 (eg Figure 3 The cross-sectional widths of the blades 3 along the length direction are equal.

[0030] The guide cone 2 of the accelerator 11 is arranged on the inner side of the terminal fixing seat 1 , and the cone of the guide cone 2 is arranged along the axis of the accelerator 11 .

[0031] The guide cone 2 includes more than one section of cone; when the cone has more than two sections, there is a smooth transition between adjacent cones. Preferably, the cone angle of the guide cone 2 close to the end fixing seat 1 is smaller than the cone angle of the front end of the cone. In this embodiment, the guide cone 2 includes two sections, the cone angle close to the end fixing seat 1 is 10-15°, and the cone angle of the front end of the cone is 55-60°.

[0032] The surface of the guide cone 2 may be in an arc shape, which makes it easier for the mud to flow from the axial direction to the radial direction. The end of the guide cone 2 may be hollow to reduce the weight of the accelerator 11.

[0033] Furthermore, the length of the guide cone 2 is 2 / 5 to 1 / 2 of the length of the blade 3 .

[0034] The radial liquid flow holes 10 on the inner cylinder 16 are arranged on the liquid inlet end fixing seat 4 close to the accelerator 11. Preferably, the guide cone 2 and the radial liquid flow holes 10 do not overlap in the radial direction.

[0035] A wear-resistant sleeve 13 is fixedly installed at the outlet end of the liquid inlet pipe 14 . The wear-resistant sleeve 13 is made of high-hardness wear-resistant steel and can reduce the erosion and wear of the particles in the mud on the outlet of the liquid inlet pipe 14 .

[0036] The radial mounting hole 6 of the liquid inlet end fixing seat 4 is fixedly connected to the end surface of the inner cylinder 16 of the screw conveyor 12 by bolts 5. The outer circumference of the terminal fixing seat 1 is provided with positioning holes 9, and the ends of the positioning screws 7 radially installed on the inner cylinder 16 are inserted into the positioning holes 9 to fix the terminal fixing seat 1. A sealing ring 8 is provided in the annular groove on the outer circumference of the terminal fixing seat 1.

[0037] The accelerator 11 in this embodiment is an integral casting, and can be installed in the inner cylinder 16 of the screw conveyor 12 only after the liquid inlet end fixing seat 4 and the end fixing seat 1 at both ends are machined.

[0038] The present invention is applied to a feeding accelerator of a drilling fluid high-speed centrifuge. The inner cylinder of the centrifuge screw conveyor is arranged in a rotary drum, the outer circumference of the inner cylinder is arranged with spiral blades, the inner cylinder is arranged with radial liquid flow holes, the accelerator is fixedly installed in the inner cylinder, the inner cylinder and the rotary drum rotate at high speed, the feeding accelerator rotates at high speed with the inner cylinder, the mud enters the cavity of the feeding accelerator through the liquid inlet pipe and the wear-resistant sleeve jet, the mud entering the accelerator axially impacts the guide cone, with the high-speed rotation of the guide cone, the mud flow is forced to change from axial flow to radial flow, the blades outside the guide cone rotate to steadily accelerate the mud, the accelerated mud is discharged through the radial liquid flow holes of the inner cylinder to the annulus between the inner cylinder and the rotary drum, the mud is separated into solid and liquid phases by the screw conveyor and then discharged. Multiple blades are arranged at intervals along the circumference of the accelerator, and their cross-sections are biaxial composite curves, and the mud is continuously and steadily accelerated and discharged in the flow channel formed when the blades rotate.

[0039] The feeding accelerator of the drilling fluid high-speed centrifuge of the present invention rotates with the screw conveyor, and the accelerator blades push the mud to flow in the annulus in an orderly and pressurized manner, so as to accelerate the discharge of the mud in the screw conveyor cavity; the blades convert the high-speed axial motion of the feeding mud into accelerated radial motion without generating turbulence, so as to avoid the problems of filling and generating turbulence in the screw conveyor cavity, mud overflowing at the inlet of the liquid inlet pipe, and unstable flow rate when the mud is discharged through the screw conveyor discharge port under the condition of large liquid supply, so as to realize the orderly and pressurized flow of the liquid flow in the screw conveyor cavity and the stable flow rate at the screw conveyor discharge port; the solid phase particles are accelerated to settle on the inner wall of the drum, so as to greatly improve the separation effect of the centrifuge.

[0040] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the claims of this patent.

Claims

1. A feeding accelerator for a drilling fluid high-speed centrifuge, comprising a screw conveyor, an inner cylinder arranged in a rotating drum, a spiral blade arranged on the outer circumference of the inner cylinder, and a radial liquid flow hole arranged on the inner cylinder, Its characteristics are: An accelerator is installed in the inner cylinder, and a guide cone is arranged along the axis of the accelerator. The outer contour of the accelerator is composed of blades arranged at intervals. The guide cone is located at the end of the accelerator and is arranged opposite to the direction of liquid flow. The axial flow of mud entering the inner cylinder is converted into radial flow, and discharged to the annulus between the inner cylinder and the drum through the radial liquid flow holes; the outlet end of the liquid inlet pipe is located in the accelerator.

2. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 1, Its characteristics are: The outer contour of the accelerator is composed of more than two blades; one end of the blade is connected to the liquid inlet end fixing seat of the accelerator, and the other end is connected to the end fixing seat of the accelerator. The surface of the blade is a spiral surface formed by a composite of double axial curves.

3. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 2, Its characteristics are: The biaxial composite curve of the blade cross section is formed by continuous rotation around the Y axis and the Z axis.

4. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 3, Its characteristics are: The biaxial composite curve of the blade cross section continuously rotates around the Y axis and the Z axis by an angle of 10 to 20 degrees.

5. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 4, Its characteristics are: The two or more blades are evenly distributed along the circumference of the accelerator.

6. A feed accelerator for a drilling fluid high-speed centrifuge according to any one of claims 3 to 5, Its characteristics are: The guide cone of the accelerator is arranged on the inner side of the terminal fixing seat, and the cone body of the guide cone is arranged along the axis of the accelerator.

7. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 6, Its characteristics are: The guide cone includes more than one section of cones; and there is a smooth transition between more than two sections of cones.

8. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 7, Its characteristics are: The length of the guide cone is 2 / 5 to 1 / 2 of the length of the blade.

9. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 8, Its characteristics are: The radial liquid flow holes on the inner cylinder are arranged close to the liquid inlet end fixing seat of the accelerator.

10. The feed accelerator of the drilling fluid high-speed centrifuge according to claim 1, Its characteristics are: A wear-resistant sleeve is fixedly installed on the outlet end of the liquid inlet pipe.

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