Method for molding a screw pump stator rubber and screw pump stator

Abstract

The application provides a screw pump stator rubber forming method and a screw pump stator, wherein the method comprises the following steps: coating adhesive on the inner wall of a stator shell; injecting heated and softened fluorine rubber into the stator shell; and after the fluorine rubber is fluidly vulcanized and shaped, milling treatment is performed to form an inner cavity structure of the screw pump stator at the center of the fluorine rubber solid, wherein a plurality of connecting pieces are embedded in the stator shell for fixing the fluorine rubber or fixing the fluorine rubber through a fixed mesh steel pipe, and the method can also inject the heated and softened fluorine rubber into a rubber injection mold and then perform installation. The screw pump stator produced by using the forming method can solve the problems of fluorine rubber used for heavy oil thermal recovery wells, such as the problem of rubber peeling caused by poor adhesion of the fluorine rubber or the problem of rubber injection cavity caused by poor flowability of the fluorine rubber, and can significantly improve the service life of the stator rubber.

Description

Technical Field

[0001] This invention relates to the field of single-screw oil pump technology, and in particular to a method for molding rubber for a screw pump stator and a screw pump stator. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this invention and does not constitute prior art.

[0003] In the extraction of heavy oil and viscous oil wells, thermal recovery is often required, with well temperatures typically exceeding 200°C. Currently, conventional screw pump stators typically use nitrile rubber or hydrogenated nitrile rubber, whose temperature resistance is insufficient for the thermal recovery requirements of heavy oil wells. Fluororubber, due to its unique CF bond structure, exhibits excellent physical and chemical stability, superior temperature and corrosion resistance, and can withstand temperatures exceeding 200°C. Therefore, fluororubber is widely used in heavy oil wells and other oil well applications.

[0004] Currently, in the process of using fluororubber, due to its poor flowability and poor adhesion, the poor flowability can lead to unfilled cavities during injection, and the poor adhesion can cause the stator rubber to detach from the stator housing during use. These phenomena seriously affect the efficiency of the actual production process and the use of equipment. Therefore, how to solve these problems is a current challenge in the field of heavy oil well single screw pump technology.

[0005] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a method for molding rubber for a screw pump stator and a screw pump stator, which solves the problems of debonding caused by poor adhesion and injection cavity caused by poor flow of fluororubber stators used in heavy oil wells and turbid oil wells in the field of single-screw oil pump technology, and can significantly improve the service life of stator rubber.

[0007] The above-mentioned objectives of this invention are mainly achieved by the following technical solutions:

[0008] A method for molding rubber for a screw pump stator, the method comprising:

[0009] An adhesive is applied to the inner wall of the stator housing;

[0010] The heated and softened fluororubber fluid medium is injected into the stator housing so that the fluororubber fluid medium fills the inner cavity of the stator housing;

[0011] The fluororubber fluid is subjected to vulcanization and shaping treatment;

[0012] The vulcanized fluororubber solid is milled to form the internal cavity structure of the screw pump stator at the center of the fluororubber solid.

[0013] In one specific embodiment, the method further includes: after milling the vulcanized fluororubber solid, embedding a plurality of connectors into the stator housing, wherein the plurality of connectors can extend into the fluororubber solid.

[0014] In one specific embodiment, the method further includes embedding a plurality of connectors on the stator housing before injecting the heated and softened fluororubber fluid medium into the stator housing.

[0015] In one specific embodiment, the method further includes: before injecting the heated and softened fluororubber fluid medium into the stator housing, inserting a perforated steel pipe into the stator housing, so that during the injection of the heated and softened fluororubber fluid medium into the stator housing, the fluororubber fluid medium can leak through the perforated steel pipe and combine with the adhesive on the inner wall of the stator housing.

[0016] A method for molding rubber for a screw pump stator, the method comprising:

[0017] A fluororubber fluid medium that is heated and softened is injected into the fluororubber injection mold, which is provided to match the inner cavity size of the stator housing.

[0018] The fluororubber fluid is subjected to vulcanization and shaping treatment;

[0019] The vulcanized fluororubber solid is milled to form the inner cavity structure of the screw pump stator at the center of the fluororubber solid;

[0020] An adhesive is applied to the inner wall of the stator housing, and the milled fluororubber solid with the internal cavity structure of the screw pump stator is inserted into the stator housing. The fluororubber solid is bonded to the stator housing by the adhesive.

[0021] In one specific embodiment, after the fluororubber solid is installed into the stator housing, a plurality of connectors are embedded in the stator housing, and the plurality of connectors can extend into the fluororubber solid.

[0022] In one specific embodiment, before injecting the heated and softened fluororubber fluid medium into the injection mold, a perforated steel pipe is inserted into the injection mold. During the injection process, the heated and softened fluororubber fluid medium can leak through the perforated steel pipe and, after cooling, form a steel pipe-fluororubber solid together with the perforated steel pipe.

[0023] After the steel tube-fluororubber solid is installed into the stator housing, multiple connectors are embedded in the stator housing. The mesh steel tube of the steel tube-fluororubber solid can be fixedly connected to the stator housing through the multiple connectors, and the fluororubber solid of the steel tube-fluororubber solid can be bonded to the adhesive on the inner wall of the stator housing.

[0024] A screw pump stator, manufactured using the aforementioned screw pump stator rubber molding method, comprises:

[0025] A stator housing having an inner cavity, wherein an adhesive layer is coated on the inner wall of the stator housing;

[0026] A fluororubber cylinder is inserted into the inner cavity, and the fluororubber cylinder is connected to the stator shell through the adhesive layer.

[0027] The stator housing is provided with multiple connectors, which can be embedded in the wall of the fluororubber cylinder.

[0028] The fluororubber cylinder contains a perforated steel tube, and the stator housing is embedded with multiple connectors that can fix the perforated steel tube to the stator housing.

[0029] Compared with the prior art, the technical solution of the present invention has the following characteristics and advantages:

[0030] 1. The present invention can achieve a fixed connection between the stator housing and the fluororubber cylinder by means of mechanical fixing, such as by bolts or other connecting parts, and / or by inserting a mesh steel pipe between the stator housing and the fluororubber cylinder, which can significantly improve the service life of the fluororubber cylinder and avoid delamination and other phenomena caused by its poor adhesion during long-term use.

[0031] 2. This invention can improve the problem of incomplete filling of cavities that are very easy to occur during the injection molding of fluororubber by using the method of injection molding inside the shell and then processing it, thereby improving product quality. Attached Figure Description

[0032] Figure 1 A flowchart of the first embodiment of the screw pump stator rubber molding method of the present invention;

[0033] Figure 2This is a flowchart of a second embodiment of the screw pump stator rubber molding method of the present invention;

[0034] Figure 3 This is a schematic diagram of the screw pump stator of the present invention having a connecting member inserted through it;

[0035] Figure 4 This is a schematic diagram showing the forming of a connecting member passing through the stator of the screw pump of the present invention;

[0036] Figure 5 This is a schematic diagram of the structure of the screw pump stator of the present invention, which has a perforated steel pipe inside.

[0037] Figure 6 This is a schematic diagram showing the forming of a perforated steel tube inside the stator of the screw pump of the present invention;

[0038] Figure 7 This is a structural diagram of the perforated steel tube of the screw pump stator of the present invention.

[0039] Explanation of icon numbers:

[0040] 1. Stator housing; 12. Adhesive layer; 13. Internal cavity structure;

[0041] 2. Solid fluororubber; 21. Fluororubber cylinder;

[0042] 3. Connectors;

[0043] 4. Mesh steel pipe; 41. Clamping clamp;

[0044] 5. Steel pipe - fluororubber solid. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0046] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0048] Implementation Method 1

[0049] like Figure 1 , Figure 3 and Figure 4 As shown, the present invention provides a method for molding rubber for a screw pump stator, the method comprising:

[0050] Step S1: Apply adhesive to the inner wall of the stator housing 1;

[0051] Step S2: Inject the heated and softened fluororubber fluid medium into the stator housing 1 so that the fluororubber fluid medium fills the inner cavity of the stator housing 1;

[0052] Step S3: Perform vulcanization and shaping treatment on the fluororubber fluid;

[0053] Step S4: Mill the vulcanized fluororubber solid 2 to form the inner cavity structure 13 of the screw pump stator at the center of the fluororubber solid 2, that is, to form a fluororubber cylinder 21.

[0054] By using this screw pump stator rubber molding method, the fluororubber can form a solid fluororubber 2 that fills the inner cavity of the stator shell 1 after cooling. Therefore, it can significantly solve the cavity problem caused by the small injection gap and large flow resistance in the fluororubber injection process in the prior art. It avoids the premature failure of the fluororubber cylinder 21 due to irregular stress during operation caused by the cavity, and improves the service life of the fluororubber cylinder 21.

[0055] like Figure 3 , Figure 4 As shown, specifically, in a feasible embodiment, after step S4, i.e., after milling the vulcanized fluororubber solid 2, multiple connectors 3 are embedded in the stator housing 1. These connectors 3 can extend into the fluororubber solid 2. In this invention, the connectors 3 can be bolts, but are not limited to this. These connectors 3 are driven from the stator housing 1 into the inner cavity of the stator housing 1 and extend into the fluororubber solid 2, without penetrating the inner cavity structure 13 of the screw pump stator. Of course, in other embodiments, multiple connectors 3 can also be embedded in the stator housing 1 between steps S3 and S4, and these connectors 3 can extend into the fluororubber solid 2; this is not a limitation. This invention achieves a stable connection between the fluororubber solid 2 and the stator housing 1 through multiple connectors 3.

[0056] In another feasible embodiment, such as Figure 3 , Figure 4 As shown, before step S2, that is, before injecting the heated and softened fluororubber fluid medium into the stator housing 1, multiple connectors 3 are embedded in the stator housing 1. In this invention, the connectors 3 can be bolts, but are not limited thereto; that is, the connectors 3 are driven into the inner cavity of the stator housing 1 from the stator housing 1, and the bolt length is selected so as not to penetrate the inner cavity structure 13 of the screw pump stator after subsequent processing. After embedding, the heated and softened fluororubber fluid medium is injected into the stator housing 1, and the part of the bolt in the inner cavity of the stator housing 1 can be bonded to the fluororubber fluid medium. Using this embodiment, the fluororubber solid 2 and the connectors 3 can be bonded more tightly, and the connection effect between the two is better.

[0057] In yet another feasible embodiment, such as Figure 5 , Figure 6 As shown, before step S2, that is, before injecting the heated and softened fluororubber fluid medium into the stator housing 1, a perforated steel tube 4 is inserted into the stator housing 1. The perforated steel tube 4 is generally a tube structure with a grid-like through hole. The outer diameter of the perforated steel tube 4 is smaller than the inner diameter of the stator housing 1, and the inner diameter of the perforated steel tube 4 is larger than the outer diameter of the inner cavity structure 13 of the screw pump stator. (See reference...) Figure 7 As shown, clamps 41 are spaced apart on the perforated steel pipe 4. After the perforated steel pipe 4 is fixedly installed, the heated and softened fluororubber fluid medium is injected into the stator housing 1. The fluororubber fluid medium can seep through the perforated steel pipe 4 and bond with the adhesive layer 12 on the inner wall of the stator housing 1. At the same time, the fluororubber fluid medium can bond with the perforated steel pipe 4. By setting the perforated steel pipe 4 between the stator housing 1 and the fluororubber solid 2, the structural stability of the screw pump stator after processing and forming can be effectively improved.

[0058] Furthermore, in this embodiment, after the perforated steel pipe 4 is inserted into the stator housing 1, multiple connectors 3 are embedded in the stator housing 1 so that the multiple connectors 3 can be bolted to the perforated steel pipe 4 by the clamp 41 of the perforated steel pipe 4, so as to fix the perforated steel pipe 4 to the stator housing 1 and prevent the possible change in position of the perforated steel pipe 4 when the fluororubber fluid medium is injected later.

[0059] Implementation Method 2

[0060] like Figure 2 As shown, the present invention also provides a method for molding rubber for a screw pump stator, the method comprising:

[0061] Step S11: Provide a slurry mold that matches the inner cavity size of the stator housing 1, and inject the heated and softened fluororubber fluid medium into the slurry mold;

[0062] Step S21: The fluororubber fluid is vulcanized and shaped to form fluororubber solid 2;

[0063] Step S31: Mill the vulcanized fluororubber solid 2 to form the inner cavity structure 13 of the screw pump stator at the center of the fluororubber solid 2.

[0064] Step S41: Apply adhesive to the inner wall of the stator housing 1, and insert the milled fluororubber solid 2 with the inner cavity structure 13 of the screw pump stator into the stator housing 1. The fluororubber solid 2 is bonded to the stator housing 1 through the adhesive layer 12.

[0065] This molding method can further improve the molding effect of fluororubber through molds, solve the problem of unfilled cavities that are easy to occur under conventional injection molding methods, and can also be installed into the inner cavity of stator housing 1 after the fluororubber fluid medium has cooled and molded, avoiding delamination or cavity problems caused by cold shrinkage.

[0066] Specifically, such as Figure 4 As shown, after step S41, that is, after the fluororubber solid 2 is installed into the stator housing 1, a plurality of connectors 3 are embedded in the stator housing 1. These connectors 3 can extend into the fluororubber solid 2. In this invention, the connectors 3 can be bolts, but are not limited to this. Simultaneously, the connectors 3 are driven from the stator housing 1 into the inner cavity of the stator housing 1, extending into the fluororubber solid 2, but do not penetrate the inner cavity structure 13 of the screw pump stator. This invention achieves a stable connection between the fluororubber solid 2 and the stator housing 1 through the plurality of connectors 3.

[0067] Furthermore, such as Figure 6 As shown, before step S11, that is, before injecting the heated and softened fluororubber fluid medium into the injection mold, a perforated steel tube 4 is inserted into the injection mold. The outer diameter of the perforated steel tube 4 is smaller than the inner diameter of the stator housing 1, and the inner diameter of the perforated steel tube 4 is larger than the outer diameter of the inner cavity structure 13 of the screw pump stator. (See reference...) Figure 7 As shown, clamps 41 are spaced apart on the perforated steel pipe 4. During the injection process of the heated and softened fluororubber fluid medium into the injection mold, it can seep through the mesh of the perforated steel pipe 4 and fill the entire injection mold. At the same time, the fluororubber fluid medium can bond with the perforated steel pipe 4. After cooling, it forms a steel pipe-fluororubber solid 5 together with the perforated steel pipe 4. After milling, the steel pipe-fluororubber solid 5 is installed into the stator housing 1. At the same time, multiple connectors 3 are embedded in the stator housing 1. The multiple connectors 3 can be bolted to the clamps 41 of the perforated steel pipe 4 to fix the perforated steel pipe 4 to the stator housing 1. The fluororubber solid 2 wrapped on the outside of the perforated steel pipe 4 can bond with the adhesive layer 12 on the inner wall of the stator housing 1.

[0068] Implementation Method 3

[0069] like Figures 3 to 6 As shown, the present invention also provides a screw pump stator, which is manufactured using the screw pump stator rubber molding method of Embodiment 1 or Embodiment 2, the screw pump stator comprising:

[0070] The stator housing 1 has an inner cavity 11, and an adhesive layer 12 is coated on the inner wall of the stator housing 1;

[0071] The fluororubber cylinder 21 is inserted into the inner cavity 11 and is connected to the stator housing 1 through the adhesive layer 12.

[0072] The screw pump stator of the present invention is manufactured using the screw pump stator rubber molding method of Embodiment 1 or Embodiment 2. It can effectively overcome the problems of degumming and cavities caused by the use of fluororubber screw pump stators in heavy oil wells and viscous oil wells due to the characteristics of fluororubber, thus enabling the screw pump to produce more efficiently.

[0073] Specifically, multiple connectors 3 are provided on the outer shell body. The multiple connectors 3 can be embedded in the cylinder wall of the fluororubber cylinder 21, and the connectors 3 do not penetrate the inner cavity structure 13 of the screw pump stator. In this invention, the connectors 3 can be bolts, but are not limited thereto.

[0074] Furthermore, the fluororubber cylinder 21 is equipped with a perforated steel pipe 4. The perforated steel pipe 4 is generally a pipe with a grid-like network of through holes. Please refer to the attached document for further details. Figure 7 As shown, clamps 41 are spaced apart on the perforated steel pipe 4, and the perforated steel pipe 4 and fluororubber are solidified and bonded together as a whole. The perforated steel pipe 4 does not penetrate the inner cavity structure 13 of the screw pump stator. At the same time, multiple connectors 3 are embedded on the outer shell body. The multiple connectors 3 can be bolted to the perforated steel pipe 4 and the outer shell body to fix the perforated steel pipe 4 to the outer shell body.

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for molding rubber for a screw pump stator, characterized in that, The method includes: An adhesive is applied to the inner wall of the stator housing; The heated and softened fluororubber fluid medium is injected into the stator housing so that the fluororubber fluid medium fills the inner cavity of the stator housing; The fluororubber fluid is subjected to vulcanization and shaping treatment; The vulcanized fluororubber solid is milled to form the inner cavity structure of the screw pump stator at the center of the fluororubber solid; Before injecting the heated and softened fluororubber fluid medium into the stator housing, a perforated steel pipe is inserted into the stator housing. During the injection of the heated and softened fluororubber fluid medium into the stator housing, the fluororubber fluid medium can leak through the perforated steel pipe and combine with the adhesive on the inner wall of the stator housing.

2. The method for molding rubber of a screw pump stator according to claim 1, characterized in that, Also includes: After the vulcanized fluororubber solid is milled, a plurality of connectors are embedded in the stator housing, and the plurality of connectors can extend into the fluororubber solid.

3. The method for molding rubber of a screw pump stator according to claim 1, characterized in that, Also includes: Before injecting the heated and softened fluororubber fluid medium into the stator housing, a plurality of connectors are embedded in the stator housing.

4. A method for molding rubber for a screw pump stator, characterized in that, The method includes: A fluororubber fluid medium that is heated and softened is injected into the fluororubber injection mold, which is provided to match the inner cavity size of the stator housing. The fluororubber fluid is subjected to vulcanization and shaping treatment; The vulcanized fluororubber solid is milled to form the inner cavity structure of the screw pump stator at the center of the fluororubber solid; An adhesive is applied to the inner wall of the stator housing, and the milled fluororubber solid with the internal cavity structure of the screw pump stator is inserted into the stator housing. The fluororubber solid is bonded to the stator housing by the adhesive.

5. The method for molding rubber of a screw pump stator according to claim 4, characterized in that, After the fluororubber solid is installed into the stator housing, a plurality of connectors are embedded in the stator housing, and the plurality of connectors can extend into the fluororubber solid.

6. The method for molding rubber of a screw pump stator according to claim 4, characterized in that, Before injecting the heated and softened fluororubber fluid medium into the injection mold, a perforated steel pipe is inserted into the injection mold. During the injection process, the heated and softened fluororubber fluid medium can seep through the perforated steel pipe and, after cooling, form a steel pipe-fluororubber solid together with the perforated steel pipe. After the steel tube-fluororubber solid is installed into the stator housing, multiple connectors are embedded in the stator housing. The mesh steel tube of the steel tube-fluororubber solid can be fixedly connected to the stator housing through the multiple connectors, and the fluororubber solid of the steel tube-fluororubber solid can be bonded to the adhesive on the inner wall of the stator housing.

7. A screw pump stator, characterized in that, The screw pump stator is manufactured using the rubber molding method described in any one of claims 1-6, wherein the screw pump stator comprises: A stator housing having an inner cavity, wherein an adhesive layer is coated on the inner wall of the stator housing; A fluororubber cylinder is inserted into the inner cavity, and the fluororubber cylinder is connected to the stator shell through the adhesive layer.

8. The screw pump stator according to claim 7, characterized in that, The stator housing is provided with multiple connectors, which can be embedded in the cylinder wall of the fluororubber cylinder.

9. The screw pump stator according to claim 7, characterized in that, The fluororubber cylinder is equipped with a perforated steel tube, and the stator shell is embedded with multiple connectors, which can fix the perforated steel tube to the stator shell.

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