A thick oil drag reducing liquid ring generator suitable for pipe bends with controllable thickness

Abstract

The present invention relates to a thick oil drag reduction liquid ring generator suitable for bends and with controllable thickness. The device consists of a straight pipe, a bend, a reducing pipe, an annular titanium steel sheet, a hoop, bolts, nuts, a multi-layer guide ring, a differential pressure transmitter, and a real-time data acquisition system. The device can control the thickness of the lubricating layer during the drag reduction process of heavy oil pipeline transportation, and at the same time ensure the stability of the flow state of the central thick oil-liquid ring after passing through the bend under different lubricating layer thicknesses. The thickness of the liquid ring can be controlled by tightening the bolts to tighten or expand the annular titanium steel sheet, thereby increasing or decreasing the gap between the reducing pipe and the annular titanium steel sheet. The stability of the liquid ring can be achieved by the multi-layer guide ring, thereby ensuring the controllability of the lubricating layer thickness and the stability of the flow through the bend.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy oil pipeline transportation, and relates to a device capable of controlling the thickness of a lubricating layer during the heavy oil lubrication and drag reduction process and ensuring that a liquid ring stably passes through a bend pipe. Background Art

[0002] As conventional oil resources become increasingly depleted, unconventional heavy crude oil will be a strategic replacement resource for global oil and gas development in the 21st century. However, the high density, high viscosity, and low fluidity of heavy oil present significant challenges and difficulties in its extraction and transportation, often requiring specialized methods to reduce flow resistance. Conventional methods for heavy oil gathering and transportation primarily rely on heating, dilution, and upgrading, but these methods are generally limited by high throughput, energy consumption, and operating costs. Currently, heavy oil liquid ring transportation is considered one of the most economical, energy-efficient, and efficient methods for reducing heavy oil flow resistance, significantly improving transportation efficiency.

[0003] Liquid ring conveying primarily involves injecting lubricating fluid into the liquid ring generator to form a lubricating layer, isolating the heavy oil from the pipe wall. However, the thickness of the liquid ring significantly impacts the drag reduction effect on heavy oil. The optimal liquid ring thickness varies depending on the heavy oil type, flow rate, pipe diameter, or temperature, and existing liquid ring generators cannot effectively adjust it. Therefore, adjusting the liquid ring thickness is a primary consideration.

[0004] At the same time, due to environmental and geological factors, buried heavy oil pipelines cannot remain completely straight. When the heavy oil-liquid ring flows through a bend, the wall surface forces the flow direction to change, making the liquid ring difficult to stabilize and significantly reducing transportation efficiency. Ensuring the stability of the liquid ring flow through the bend is also key to achieving lubrication and drag reduction in pipeline transportation of heavy oil.

[0005] Therefore, the present invention designs a thick oil drag reducing liquid ring generator which is applicable to pipe bends and has controllable thickness and can be used for experimental research or field application. Summary of the Invention

[0006] The present invention aims to provide a thick oil drag reducing liquid ring generator suitable for pipe bends with controllable thickness, which can adjust the thickness of the lubricating liquid ring transported by the thick oil pipeline while ensuring that the liquid ring can pass through the pipe bend stably.

[0007] To achieve the above functions, the technical method of the present invention is as follows:

[0008] A thick oil drag-reducing liquid ring generator suitable for pipe bends with controllable thickness. The device consists of a straight pipe, a curved pipe, a reducing pipe, an annular titanium steel sheet, a band, bolts, nuts, a multi-layer guide ring, a differential pressure transmitter, and a real-time data acquisition system. The reducing pipe, straight pipe, and curved pipe are connected together to form a test pipe section. The straight pipe section is equipped with a differential pressure transmitter, which is connected to the real-time data acquisition system to continuously record changes in pressure drop within the pipe. The reducing pipe has a circular hole on each side: the side hole B connects to the oil pipeline, and the upper hole A connects to the lubricating liquid pipeline.

[0009] A variable-diameter oil distribution ring is installed inside the reducing pipe. It consists of a band, an annular titanium steel sheet, bolts, and nuts. The band is in the shape of a slender, non-angular rectangular parallelepiped with a long gap on the slender side. The annular titanium steel sheet passes through the middle. Three threaded holes penetrate below the long gap, and three bolts are inserted into each. The left and right bolts clamp the annular titanium steel sheet. The middle bolt can fix the entire piece to the reducing pipe. Nuts are installed on the top of the three bolts to prevent the bolts from falling. There are multiple slots on both sides of the annular titanium steel sheet for engaging with the threads of the bolts. One side of the annular titanium steel sheet is concentric with the circular hole B on the side of the reducing pipe. The diameter is always larger than the circular hole B, but always smaller than the minimum diameter of the reducing pipe.

[0010] The multi-layer guide ring is aligned with the bend angle and fixed at the center of the bend. It consists of small rings of varying diameters, all with a consistent shape and a common axis. As the central heavy oil-liquid ring flows through the bend, the multi-layer guide ring separates the heavy oil and liquid rings. After the flow is diverted through the bend, it converges and re-establishes a central heavy oil-liquid ring flow pattern. Furthermore, even if the thickness of the liquid ring changes, the multi-layer ring structure ensures that the liquid ring and heavy oil flow through the bend are fully separated.

[0011] The annular titanium steel sheet is a composite material of titanium and steel, which has good flexibility. All other devices are made of stainless steel.

[0012] Using a thickness-controllable thick oil drag-reducing liquid ring generator suitable for pipe bends, the thickness of the drag-reducing lubricating layer for thick oil pipeline transportation can be controlled while ensuring the lubricating layer's stable flow through the bend. To determine the optimal thickness of the drag-reducing liquid ring for pipeline transportation under different thick oil types and flow rates, lubricating liquid is first injected through circular hole A. The lubricating liquid flows through the gap between the reducer and the annular titanium steel sheet before entering the straight pipe. The reducer accelerates liquid flow and provides a certain centrifugal force, ensuring the shape of the liquid ring is stable. After the differential pressure transmitter detects a stable pressure drop in the lubricating liquid, the thick oil flows through circular hole B into the annular titanium steel sheet and further into the straight pipe. Once the overall pressure drop stabilizes, the three bolts on the band are simultaneously tightened. The threads of the left and right bolts engage with the slots, tightening or expanding the annular titanium steel sheet. The center bolt controls the position of the annular titanium steel sheet, ensuring its side faces are always concentric with circular hole B in the reducer. All three bolts extend beyond the reducer, forming a helical, sealed connection to the reducer. When the annular titanium steel sheet contracts, the lubricant flow gap increases, thickening the liquid ring. When the annular titanium steel sheet expands, the liquid ring thins, thus achieving controllable liquid ring thickness. When the annular titanium steel sheet is adjusted to a certain size, the pressure drop across the differential pressure transmitter is minimized, indicating the optimal thickness for the drag-reducing liquid ring used in heavy oil pipeline lubrication. When the central heavy oil-liquid ring flows through the bend, the heavy oil flows into the annular gap at or near the center of the multi-layer guide plate, while the lubricant flows into the annular gap on the outer side of the multi-layer guide plate, thereby separating the heavy oil and lubricant. After flowing out of the multi-layer guide plate, the heavy oil and lubricant remain in the center and wall of the pipe, respectively, maintaining the flow state of the central heavy oil-liquid ring, effectively preventing the lubricant from failing after flowing into the bend.

[0013] The present invention adopts the above technical solution and has the following advantages:

[0014] 1. When lubricating and reducing drag in heavy oil pipelines, different heavy oil types, oil flow rates, and pipe diameters require different lubricant thicknesses. The present invention can adjust the thickness of the liquid ring to ensure that the optimal thickness can be adjusted under different conditions.

[0015] 2. The diameter of the reducer is continuously reduced. When the lubricating liquid flows through it, the liquid flow rate can be increased, thereby improving the formation efficiency of the liquid ring. At the same time, the reducer can provide a certain centrifugal force for the liquid, making the liquid ring more stable.

[0016] 3. When the central thick oil-liquid ring flows through the bend, the liquid ring is easily damaged, thereby rendering the lubrication and drag reduction ineffective. The present invention can ensure the stability of the liquid ring after flowing through the bend, thereby greatly improving the transportation efficiency and is expected to be applied in experiments or on-site. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view of the center of the device;

[0018] Figure 2 It is a three-dimensional diagram of the entire device;

[0019] Figure 3 It is a three-dimensional image of a ring-shaped titanium steel sheet;

[0020] Figure 4 It is a three-dimensional diagram of a multi-layer guide ring;

[0021] Figure 5 It is a stereoscopic diagram of the connection of the band, bolts and nuts;

[0022] Figure 6 A three-dimensional diagram of a variable-diameter oil distribution ring connected by a band and an annular titanium steel sheet.

[0023] Among them: 1. Bend; 2. Straight pipe; 3. Reduced pipe; 4. Annular titanium steel sheet; 5. Hoop; 6. Round hole A; 7. Round hole B; 8. Bolts on both sides of the hoop; 9. Bolts in the middle of the hoop; 10. Annular gap of the multi-layer guide plate; 11. Connecting block for fixing the multi-layer guide plate and the bent pipe; 12. Slot; 13. Long gap connecting the hoop and the annular titanium steel sheet; 14. Differential pressure transmitter; 15. Real-time data acquisition system; 16. Nut; 17. Multi-layer guide ring. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] A thick oil drag reducing liquid ring generator suitable for bend pipes with controllable thickness. The supporting device consists of a straight pipe, a bend pipe, a reducing pipe, an annular titanium steel sheet, a hoop, bolts, nuts, a multi-layer guide ring, a differential pressure transmitter, and a real-time data acquisition system. The bend pipe (1), the straight pipe (2) and the reducing pipe (3) are connected together to form the supporting device, such as Figure 2 As shown. A differential pressure transmitter (14) is installed in the straight pipe section, which is connected to a real-time data acquisition system (15) to record the pressure drop change in the pipe at all times. There is a circular hole on each side of the reducing pipe, the side circular hole B (7) is connected to the oil pipe, and the upper circular hole A (6) is connected to the lubricating liquid pipe.

[0026] A variable diameter oil distribution ring is installed inside the reducing pipe, such as Figure 6As shown, the hoop is composed of a band (5), an annular titanium steel sheet (4), a middle bolt (9) of the band, bolts (8) on both sides and nuts (16). The band is in the shape of an elongated rectangular parallelepiped without edges and corners, with a long gap (13) on the elongated surface. The annular titanium steel sheet passes through the middle, and three threaded holes are penetrated below the long gap, and three bolts are inserted respectively. The bolts (8) on both sides clamp the annular titanium steel sheet, and the middle bolt (9) can fix the whole on the reducing pipe. Nuts (16) are installed on the tops of the three bolts to prevent the bolts from falling, and the three bolts extend outside the reducing pipe and are connected to the reducing pipe spirally. There are multiple slots (12) on both sides of the annular titanium steel sheet for engaging with the threads of the bolts; one side of the annular titanium steel sheet is concentric with the circular hole B (7) on the side of the reducing pipe, and the diameter is always larger than the circular hole B, but smaller than the minimum diameter of the reducing pipe.

[0027] Multi-layer guide ring (17) such as Figure 4 As shown, it is consistent with the bending angle of the bend and is fixed at the center of the bend. The multi-layer guide ring is composed of small bends of different diameters. All the bends have the same shape and have the same axis to form an annular gap (10). When the central heavy oil-liquid ring flows through the bend, the multi-layer guide ring can separate the heavy oil and the liquid ring, and when the diversion converges through the bend, it can re-form the flow state of the central heavy oil-liquid ring. At the same time, when the thickness of the liquid ring changes, the structural design of the multi-layer circular ring can still ensure that the liquid ring and the heavy oil are fully separated when flowing through the bend, ensuring that the liquid ring is formed again when converging. The annular titanium steel sheet is a composite material of titanium steel, and all other devices are made of stainless steel.

[0028] The invention relates to a thick oil drag-reducing liquid ring generator suitable for pipe bends and having controllable thickness. The thickness of the thick oil pipeline drag-reducing lubricating layer can be controlled while ensuring that the lubricating layer passes through the pipe bend stably. To determine the optimal thickness of the pipeline drag-reducing liquid ring under different thick oil types and flow rates, lubricating liquid is first injected from the circular hole A (6). The lubricating liquid flows through the gap between the reducing pipe (3) and the annular titanium steel sheet (4) and then flows into the straight pipe. The reducing pipe can accelerate the flow of liquid and provide a certain centrifugal force to ensure the stable formation of the liquid ring. After the differential pressure transmitter (14) detects that the pressure drop of the lubricating fluid is stable, the heavy oil flows from the circular hole B (7) into the annular titanium steel sheet and further into the straight pipe (2). After the pressure drop is stable, the three bolts on the hoop are simultaneously turned, and the threads of the bolts (8) on the left and right sides are engaged with the slots (12), which can tighten or expand the annular titanium steel sheet (4). The middle bolt (9) is used to ensure that the annular titanium steel sheet is in the center of the reducing pipe (3) so that its side is always concentric with the circular hole B (7) of the reducing pipe. When the annular titanium steel sheet is tightened, the flow gap of the lubricating fluid increases and the liquid ring becomes thicker. When the annular titanium steel sheet is expanded, the liquid ring becomes thinner, thereby achieving controllable liquid ring thickness. When the annular titanium steel sheet is adjusted to a certain size, the pressure drop of the differential pressure transmitter (14) is minimum, and this is the optimal thickness of the lubricating drag reducing liquid ring for the heavy oil pipeline. When the central heavy oil-liquid annular flow passes through the elbow, the heavy oil flows into the annular gap (10) at or near the center of the multi-layer guide plate, while the lubricating liquid flows into the annular gap on the outer side of the multi-layer guide plate, thereby achieving separation of the heavy oil and the lubricating liquid. After flowing out of the multi-layer guide plate, the heavy oil and the lubricating liquid remain in the center of the pipe and on the pipe wall, respectively, and the flow state of the central heavy oil-liquid annular flow can still be guaranteed, thereby effectively avoiding lubrication failure after flowing into the elbow.

Claims

1. A thick oil drag-reducing liquid ring generator suitable for pipe bends with controllable thickness, capable of adjusting the thickness of the lubricating liquid ring for lubricating and reducing drag in heavy oil pipelines, while ensuring stable flow of the central thick oil-liquid ring through the pipe bend, characterized by: The supporting device is composed of a straight pipe, a curved pipe, a reducing pipe, an annular titanium steel sheet, a hoop, bolts, nuts, a multi-layer guide ring, a differential pressure transmitter, and a real-time data acquisition system; the curved pipe (1), the straight pipe (2) and the reducing pipe (3) are connected together to form the supporting device; the straight pipe section is equipped with a differential pressure transmitter (14), which is connected to the real-time data acquisition system (15) and can record the pressure drop change in the pipe at all times; the reducing pipe has a circular hole on both sides, the side circular hole B (7) is connected to the oil delivery pipe, and the upper circular hole A (6) is connected to the lubricating liquid delivery pipe; a variable diameter oil distribution ring is installed inside the reducing pipe, and the variable diameter oil distribution ring is composed of a hoop (5), an annular titanium steel sheet (4), a bolt in the middle of the hoop (9), bolts on both sides (8) and nuts (16); the hoop is in the shape of a slender rectangular parallelepiped without edges and corners, and the slender surface has a long gap (13), the annular titanium steel sheet (4) passes through the long gap, and the bottom of the long gap passes through Three threaded holes are passed through, and three bolts are inserted respectively. The bolts (8) on both sides clamp the annular titanium steel sheet, and the middle bolt (9) can fix the whole on the reducing pipe. Nuts (16) are installed on the top of the three bolts to prevent the bolts from falling, and the three bolts are extended to the outside of the reducing pipe and are connected to the reducing pipe spiral seal; multiple grooves (12) are provided on both sides of the annular titanium steel sheet for engaging with the threads of the bolts; one side of the annular titanium steel sheet is concentric with the circular hole B (7) on the side of the reducing pipe, and the diameter is always larger than the circular hole B, but always smaller than the minimum diameter of the reducing pipe; the multi-layer guide ring (17) is consistent with the bending angle of the bend pipe and is fixed at the center of the bend pipe; the multi-layer guide ring is composed of small bend rings of different diameters, all of which have the same shape and the same axis, forming an annular gap (10) and fixed at the center of the bend pipe; the annular titanium steel sheet is a composite material of titanium and steel and has good flexibility, and all other devices are made of stainless steel.

2. A thick oil drag reducing liquid ring generator suitable for pipe bends and with controllable thickness as claimed in claim 1 is used, characterized in that: In order to determine the optimal thickness of the pipe-transported drag-reducing liquid ring under different heavy oil types and flow rates, the lubricating liquid is first injected from the circular hole A (6), and the lubricating liquid flows through the gap between the reducing pipe (3) and the annular titanium steel sheet (4) and then flows into the straight pipe; after the differential pressure transmitter (14) measures the pressure drop of the lubricating liquid flow to be stable, the heavy oil flows from the circular hole B (7) into the annular titanium steel sheet and further into the straight pipe (2). After the overall pressure drop is stable, the three bolts on the hoop are simultaneously screwed, and the threads of the bolts (8) on the left and right sides are engaged with the grooves (12), which can tighten or expand the annular titanium steel sheet (4). The middle bolt (9) is used to ensure that the annular titanium steel sheet is in the reducing pipe (3). The center of the multi-layer guide plate is formed so that its side surface is always concentric with the circular hole B (7) of the reducing pipe; when the annular titanium steel sheet is tightened, the flow gap of the lubricating liquid increases and the liquid ring becomes thicker, and when the annular titanium steel sheet is expanded, the liquid ring becomes thinner; the optimal lubricating thickness is determined by the minimum pressure drop measured by the differential pressure transmitter (14); when the central heavy oil-liquid ring flows through the bend, the heavy oil flows into the annular gap (10) at the center or near the center of the multi-layer guide plate, and the lubricating liquid flows into the annular gap on the outer side of the multi-layer guide plate, thereby achieving separation of the heavy oil and the lubricating liquid; after flowing out of the multi-layer guide plate, the heavy oil and the lubricating liquid are still in the center of the pipeline and on the side of the pipe wall respectively, and the flow state of the central heavy oil-liquid ring can still be guaranteed.

3. The thick oil drag reducing liquid ring generator suitable for pipe bends and with controllable thickness as claimed in claim 1 is characterized in that: The inner diameter of the reducing pipe (3) is continuously reduced, which can increase the flow rate of the lubricating liquid and promote the formation of the liquid ring; and the continuous reduction of the pipe diameter can provide a certain centrifugal force for the lubricating liquid, making the liquid ring more stable.

4. The thick oil drag reducing liquid ring generator suitable for pipe bends and with controllable thickness as claimed in claim 1 is characterized in that: The thickness of the lubricating liquid required for different thick oil types, oil flow rates and pipe diameters is different. By turning the bolts (8) on both sides, the annular titanium steel sheet (4) can be reduced or expanded, and the gap between the liquid ring and the straight pipe (2) can be reduced or increased, thereby controlling the thickness of the liquid ring. The thickness under the minimum pressure drop is then measured by the differential pressure transmitter (14), ensuring that the best lubrication effect can be achieved under different conditions.

5. The thick oil drag reducing liquid ring generator suitable for pipe bends and with controllable thickness as claimed in claim 1 is characterized in that: When the central heavy oil-liquid ring flows through the elbow, the multi-layer guide ring can separate the heavy oil and the liquid ring, and when the heavy oil flows out of the elbow and converges, the flow state of the central heavy oil-liquid ring can be re-formed. When the thickness of the liquid ring changes, the annular gap (10) occupied by the heavy oil increases or decreases, but the structural design of the multi-layer annular gap can still ensure that the liquid ring and the heavy oil are effectively separated when flowing through the elbow, and maintain the flow state of the central heavy oil-liquid ring.

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