Rotary Flow Positioner

Abstract

This utility model relates to the field of oil and gas drilling technology, specifically a rotary flow stabilizer. This utility model includes a central steel pipe, fixing screws, a rectangular toothed spiral pressure plate, and a spiral rubber wing. The spiral rubber wing is riveted to the outer wall of the central steel pipe by the pressure plate and screws. Its unique feature is that the wing adopts a variable lift angle spiral design, forming a converging flow channel with an upward cross-sectional area. The central steel pipe is the main support structure of this tool, and its inner diameter is slightly larger than the nominal outer diameter of the casing to facilitate its installation on the outside of the casing. The spiral rubber wing is the core functional component. After being lowered into the well, the cement slurry flowing through it is accelerated and transformed into a strong spiral turbulence, generating lateral scouring of the well wall, effectively removing mud cake, breaking the boundary layer, and displacing stagnant drilling fluid, significantly improving the displacement efficiency and cementing quality of "large belly" well sections and oil-bearing sections. This utility model has a reliable structure, is easy to install, and has strong adaptability, making it an effective tool for solving complex wellbore cementing problems.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas drilling technology, and in particular to a rotary flow stabilizer positioner. Background Technology

[0002] After drilling is completed, cementing operations are required. This involves running the casing and injecting cement slurry into the annular space between the casing and the wellbore. Once the cement slurry solidifies, it forms a hard cement sheath that seals the formation, supports the casing, and protects the oil and gas reservoir. The quality of cementing directly affects the long-term safe production and recovery rate of oil and gas wells.

[0003] However, in actual cementing operations, the problem of poor displacement efficiency is often encountered. Especially in well sections with irregular boreholes and enlarged diameters, conventional laminar flow displacement methods often result in cement slurry easily flowing into channels, failing to effectively displace the drilling fluid (mud), leading to poor cement sheath bonding and the formation of micro-gaps or even oil, gas, and water passageways. In addition, the thick mud cake formed on the wellbore surface also severely reduces the bonding strength between the cement slurry and the formation.

[0004] In existing technologies, tools such as centralizers, mud scrapers, and turbulence generators are commonly used to improve displacement efficiency. Centralizers mainly serve a centralizing function and have limited effect on improving fluid flow patterns; mud scrapers can remove some mud cake, but cannot effectively solve the problem of cement slurry channeling in large-diameter well sections; while traditional turbulence generators mostly use rigid blades or simple guide channels, which generate limited turbulence intensity, have a localized effect, and may pose a scraping risk to the well wall, making them unsuitable for complex wellbores.

[0005] Therefore, there is an urgent need in this field for a new type of auxiliary tool that can effectively break up the laminar boundary layer, clean the wellbore, induce strong turbulence, and adapt to different wellbore sizes, so as to fundamentally improve the cement slurry displacement efficiency and sealing quality under complex well conditions. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies, particularly in cementing operations in "large belly" well sections and oil-bearing well sections, such as low cement slurry displacement efficiency, incomplete removal of mud cake from the well wall, and easy occurrence of cement slurry channeling leading to poor cementing quality. Therefore, a rotary flow stabilizing positioner is proposed.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a rotary flow stabilizer, comprising a central steel pipe, a fixing screw, a rectangular toothed spiral pressure plate, and a spiral rubber wing.

[0008] The central steel pipe is the main support structure of this tool. Its inner diameter is slightly larger than the nominal outer diameter of the sleeve so that it can be fitted onto the outside of the sleeve.

[0009] The spiral rubber blades are the core functional components, and there are at least two, preferably four, evenly distributed along the outer circumference of the central steel pipe. The spiral rubber blades extend spirally around the axis of the central steel pipe, and their key feature is that the helix angle varies, gradually decreasing from the lower end to the upper end of the tool. This unique design naturally creates several spiral-shaped flow channels between the multiple spiral rubber blades and the well wall, with the cross-sectional area gradually converging from bottom to top (i.e., gradually expanding from top to bottom).

[0010] The rectangular toothed spiral pressure plate is used to firmly press the spiral rubber wing onto the outer wall of the central steel pipe. Its shape is precisely matched with the spiral direction of the spiral rubber wing, and its lower surface (the side in contact with the rubber wing) is machined with rectangular toothed or other shaped anti-slip serrations to greatly increase the friction between the pressure plate and the rubber wing and provide a strong biting force to prevent the rubber wing from shifting or falling off under the impact of high-pressure fluid.

[0011] The fixing screws pass through the pre-set holes on the rectangular toothed spiral pressure plate and the spiral rubber wings, and finally screw into the threaded hole on the central steel pipe wall, thereby tightly riveting and fixing the entire assembly together.

[0012] The cross-section of the helical rubber wing is one of trapezoidal, rectangular, or semi-elliptical.

[0013] The inner wall of the central steel pipe may be coated with an anti-rust coating or plating.

[0014] The spiral rubber wing is made of wear-resistant, high-temperature resistant, and alkali-resistant nitrile rubber, hydrogenated nitrile rubber, or fluororubber.

[0015] In summary, the beneficial effects of this utility model are as follows: 1. Highly efficient induction of strong turbulence: When cement slurry (or pre-fluid) flows upward through the converging channel formed by the variable-lift-angle helical blade, the flow direction of the fluid is forcibly changed, the flow velocity is significantly enhanced, and the flow instantly changes from laminar flow to strong spiral turbulence. This high-energy turbulence effectively breaks up the laminar boundary layer attached to the wellbore and casing walls, greatly improving the fluid's ability to entrain and suspend drilling fluid and cement slurry particles.

[0016] 2. Comprehensive wellbore cleaning: The strong spiral jet generates a continuous and uniform lateral scouring force on the wellbore, which can effectively remove loose mud cake and drilling fluid residue on the wellbore, creating a clean interface condition for the direct and tight bonding of cement slurry and formation rock, and fundamentally eliminating the problem of deterioration of bonding strength caused by the presence of mud cake.

[0017] 3. Significantly improves displacement efficiency: The spiral-forward flow pattern has a strong lateral sweeping ability, which can effectively displace the drilling fluid retained in the "big belly" section of the well, eliminate the phenomenon of cement slurry channeling, and ensure that the annular space is uniformly and completely filled with high-quality cement slurry.

[0018] 4. Adaptability and protection: The propeller is made of rubber, which has a certain degree of elasticity and wear resistance. It can adapt to the slight changes in different wellbore sizes, ensuring effective contact with the well wall to form a flow channel, while avoiding the risk of scraping or jamming that rigid tools may cause to the well wall (especially in loose formations).

[0019] 5. Simple structure and reliable installation: The tool features an ingenious structural design, using a rectangular toothed pressure plate and screw riveting for a secure and reliable fixation method that can withstand complex fluid forces and vibrations downhole. Installation is simple; just select the appropriate model according to the casing size and fix it at the designed well depth, without any additional complex operations. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the working state of the present invention when it is installed on the casing string and lowered into the "big belly" well section; Legend: 1. Central steel pipe; 2. Fixing screw; 3. Serrated spiral pressure plate; 4. Spiral rubber wing; 5. Casing; 6. Well wall; 7. Well section. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] See Figure 1 A preferred embodiment of the rotary flow stabilizer of this utility model includes: a central steel pipe 1, multiple fixing screws 2, four rectangular toothed spiral pressure plates 3 and four spiral rubber wings 4.

[0023] The central steel pipe 1 is made of high-strength alloy steel, and its length can be designed as needed, for example, 800 mm. The inner diameter is precisely machined according to the casing specifications; for example, for a 5.5-inch casing, its inner diameter is slightly larger than 139.7 mm to ensure smooth insertion. The steel pipe wall thickness has sufficient strength to withstand installation and downhole pressure.

[0024] The spiral rubber blade 4 is integrally vulcanized from hydrogenated nitrile butadiene rubber (HNBR) that is resistant to high temperatures (up to 120°C and above), alkali corrosion, and wear. Its cross-section is preferably trapezoidal to provide good structural strength and flow guidance. Four rubber blades are evenly spaced at 90-degree intervals around the outer wall of the central steel tube 1. The helix angle of each rubber blade smoothly transitions from a larger angle (e.g., 45°) at the bottom of the tool to a smaller angle (e.g., 20°) at the top of the tool. This variable helix angle design is the core of forming the converging flow channel.

[0025] The rectangular toothed spiral pressure plate 3 is made of hardened steel, and its shape perfectly matches the path of the spiral rubber wing 4. Its lower surface is milled with dense rectangular toothed patterns. When the fixing screw 2 is tightened, these teeth can deeply bite into the material of the rubber wing 4, forming a mechanical interlock and providing an anti-slip fixing effect far exceeding that of ordinary friction.

[0026] During assembly, first attach the spiral rubber wing 4 to the outer wall of the central steel pipe 1 according to the design orientation, then align the rectangular tooth spiral pressure plate 3 and cover the rubber wing 4. Use a special tool to pass the fixing screw 2 (such as an internal hexagonal head screw) through the pre-made holes of the pressure plate 3 and the rubber wing 4, and finally screw it into the threaded hole on the central steel pipe 1 and apply the specified torque to tighten it to ensure that the connection is absolutely reliable.

[0027] like Figure 2 As shown, in actual cementing operations, firstly, a rotary flow stabilizer (SLW-5 1 / 2in) of the corresponding model is selected based on the size of the casing string 5 (e.g., 5.5 inches). Based on the location of the "bulge" section 7 or the oil layer section determined by logging data, the tool is fitted onto the outside of the casing 5 and finally secured at the designated depth using the fixing screw 2. After running the casing to the designed well depth, cementing operations begin.

[0028] The cement slurry flows upward under pump pressure. When it flows through the rotary flow stabilizer, it is confined within four spiral guide channels formed by four spiral rubber blades 4 and the well wall 6. As the cross-sectional area of ​​the channels gradually decreases upward, the flow velocity of the cement slurry increases sharply and it is forced to spiral upward, generating a strong centrifugal force that thoroughly flushes the well wall 6, removes mud cake, and agitates and displaces the stagnant drilling fluid, completely transforming laminar flow into high-energy turbulent flow. This greatly improves the displacement efficiency of this critical well section, ultimately resulting in a dense, uniform, and well-bonded cement sheath.

[0029] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A rotary current stabilizer, characterized in that include: A central steel pipe (1), a fixing screw (2), a rectangular toothed spiral pressure plate (3), and at least two spiral rubber wings (4); the central steel pipe (1) is used to be sleeved on the outside of the casing; the spiral rubber wings (4) are fixedly riveted to the outer wall of the central steel pipe (1) by the rectangular toothed spiral pressure plate (3) and the fixing screw (2); the spiral rubber wings (4) extend spirally around the axis of the central steel pipe (1), and their spiral helix angle gradually decreases from bottom to top, thereby forming a spiral guide channel with a converging cross-sectional area from top to bottom between the outside of the tool and the well wall.

2. The rotary current stabilizer positioner of claim 1, wherein, The number of spiral rubber wings (4) is four, which are evenly distributed on the outer circumference of the central steel pipe (1).

3. A rotary current stabilized positioner according to claim 1 or 2, characterized in that The cross-section of the spiral rubber wing (4) is one of trapezoidal, rectangular or semi-elliptical.

4. The rotary current stabilizer positioner of claim 1, wherein, The shape of the rectangular toothed spiral pressure plate (3) matches the spiral direction of the spiral rubber wing (4), and its lower surface is provided with anti-slip teeth to increase friction and engagement depth.

5. The rotary current stabilizer positioner of claim 1, wherein, The inner wall of the central steel pipe (1) may be coated with an anti-rust coating or plating.

6. The rotary current stabilizer positioner of claim 1, wherein, The spiral rubber wing (4) is made of wear-resistant, high-temperature resistant, and alkali-resistant nitrile rubber, hydrogenated nitrile rubber, or fluororubber.

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