A soluble cementing graded hoop

Abstract

This utility model belongs to the field of oil and gas well cementing technology, and specifically relates to a soluble cementing stage collar, including an outer cylinder, a central tube, an upper connector connected to the upper end of the outer cylinder and the central tube, and a lower connector connected to the lower end. The inner wall of the outer cylinder is connected to a closing sleeve and an opening sleeve from top to bottom through a first shear connector and a second shear connector, respectively. A retaining spring is connected between the upper end of the closing sleeve and the central tube. A soluble closing plug seat is connected inside the central tube. Corresponding circulation holes are provided on both the outer cylinder and the central tube. This utility model provides a soluble cementing stage collar that can reliably dissolve in the downhole environment after cementing operations are completed, avoiding complex operations such as subsequent drilling and removal, while also having good sealing performance, thereby improving the efficiency and quality of cementing operations and reducing operational risks and costs.

Description

Technical Field

[0001] This utility model belongs to the field of oil and gas well cementing technology, and specifically relates to a soluble cementing graded clamp. Background Technology

[0002] In oil and gas drilling and cementing operations, staged cementing technology is commonly used in long well sections or low-pressure, easily lost-circuit formations. It controls annular pressure and reduces the risk of leakage by injecting cement slurry in stages. Traditional staged cementing collars suffer from problems such as the need to drill out internal components after the operation, poor sealing performance, and slurry leakage under high pressure. While existing soluble staged cementing collars avoid the drilling process, they largely rely on the downhole environment for dissolution, making precise control of the dissolution process difficult and posing a risk of premature or delayed dissolution affecting subsequent operations. Furthermore, some staged cementing collars that use dissolving agents have limited dissolution storage capacity, making it difficult to meet the dissolution requirements under complex operating conditions. The pre-filling of storage chambers with dissolving agents also poses a risk of leakage during transportation and installation. Utility Model Content

[0003] This invention provides a soluble cementing grader, which can solve the problems pointed out in the background art.

[0004] A soluble cementing staged collar includes an outer cylinder, a central tube, an upper connector connected to the upper end of the outer cylinder and the central tube, and a lower connector connected to the lower end. The inner wall of the outer cylinder is connected to a closing sleeve and an opening sleeve from top to bottom through a first shear connector and a second shear connector, respectively. A retaining spring is connected between the upper end of the closing sleeve and the central tube. A soluble closing plug seat is connected inside the central tube. Corresponding circulation holes are provided on both the outer cylinder and the central tube.

[0005] Preferably, the soluble closure plug is a soluble aluminum-magnesium alloy closure plug.

[0006] Preferably, both the first shear connector and the second shear connector are shear studs.

[0007] Preferably, the retaining ring is a serrated retaining ring.

[0008] Preferably, a soluble shut-off plug is connected inside the central tube via a set screw.

[0009] Beneficial effects: This utility model provides a soluble cementing graded clamp; it can reliably dissolve in the downhole environment after cementing operations are completed, avoiding complex operations such as subsequent drilling and removal, while having good sealing performance, thereby improving the efficiency and quality of cementing operations and reducing operational risks and costs. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of this utility model. Explanation of reference numerals in the attached figures: The following labels are used in the diagram: Outer cylinder 1; Central tube 2; Upper connector 3; Lower connector 4; First shear connector 5; Second shear connector 6; Closing sleeve 7; Opening sleeve 8; Snap ring 9; Soluble closing plug seat 10; Circulation hole 11; Set screw 12. Detailed Implementation

[0011] The following describes a specific embodiment of the present invention in detail with reference to the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0012] Example: Figure 1 As shown in the figure, the soluble cementing stage collar provided by this utility model includes an outer cylinder 1, a central pipe 2, an upper connector 3 connected to the upper end of the outer cylinder 1 and the central pipe 2, and a lower connector 4 connected to the lower end. The outer cylinder 1, the central pipe 2, etc. are made of high-strength alloy steel, which has good pressure resistance and corrosion resistance, and can withstand the complex pressure and harsh chemical environment downhole. The outer cylinder 1 and the central pipe 2 are connected to the upper connector 3 and the lower connector 4 by threads to ensure that a complete tubing string structure is formed. The inner wall of the outer cylinder 1 is connected from top to bottom by a first shear connector 5 and a second shear connector 6. The second shear connector 6 connects the closing sleeve 7 and the opening sleeve 8. Both the first shear connector 5 and the second shear connector 6 are shear studs, such as copper shear studs. A retaining spring 9 is connected between the upper end of the closing sleeve 7 and the central tube 2. The upper end of the closing sleeve 7 is provided with a serrated internal thread. The retaining spring 9 is a serrated retaining spring. A soluble closing plug seat 10 is connected inside the central tube 2. Specifically, the soluble closing plug seat 10 can be connected inside the central tube 2 through a set screw 12. The outer cylinder 1 and the central tube 2 are respectively provided with circulation holes 11. The soluble closing plug seat 10 is a soluble aluminum-magnesium alloy closing plug seat. When staged cementing operations are required, pressure is transmitted to the opening sleeve 8 through the circulation hole at the lower end of the central tube 2. Under the action of pressure, the second shear force connection 6 between the opening sleeve 8 and the outer cylinder 1 is sheared, allowing the opening sleeve 8 to slide relative to the central tube 2 and the outer cylinder 1, thereby opening the circulation hole 11 and realizing the circulation channel of cement slurry. After the cementing operation is completed, when the closing plug is engaged with the soluble closing plug seat 10, pressure is transmitted to the closing sleeve 7 through the flow hole at the upper end of the central tube 2, and the first shear force connection 5 between the closing sleeve 7 and the outer cylinder 1 is sheared, so that the closing sleeve 7 reaches the closed position. Through the snap ring 9 set at the upper end of the closing sleeve 7, after the closing sleeve 7 reaches the closed position, the snap ring 9 can engage with the sawtooth on the outer circle of the central tube 2, which can prevent the closing sleeve 7 from retracting and prevent the cement slurry from flowing back.

[0013] The soluble shut-off plug 10 is a soluble aluminum-magnesium alloy shut-off plug, which can be AG18. It reacts and dissolves rapidly with the dissolving solution, which is a chloride ion solution, such as sodium chloride or potassium chloride. The specific operation is as follows: chloride ion solution is added to the pre-filled liquid after cement grouting and the replacement liquid after the rubber stopper, and reacts and dissolves with the soluble shut-off plug 10. The soluble plug seat 10 has good stability in conventional downhole fluids and can quickly undergo a chemical reaction after contact with the dissolving liquid, so that the graded clamping components can be dissolved after cementing operations without the need for subsequent drilling operations.

[0014] The above-disclosed embodiments are only a few specific examples of the present utility model. However, the embodiments of the present utility model are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present utility model.

Claims

1. A soluble cementing stage clamp, comprising an outer cylinder (1), a central tube (2), an upper connector (3) connected to the upper end of the outer cylinder (1) and the central tube (2), and a lower connector (4) connected to the lower end. The inner wall of the outer cylinder (1) is connected to a closing sleeve (7) and an opening sleeve (8) from top to bottom by a first shear connector (5) and a second shear connector (6), respectively. A retaining ring (9) is connected between the upper end of the closing sleeve (7) and the central tube (2). A soluble closing plug seat (10) is connected inside the central tube (2). A circulation hole (11) is provided on both the outer cylinder (1) and the central tube (2).

2. The soluble cementing grader according to claim 1, characterized in that: The soluble closure plug (10) is a soluble aluminum-magnesium alloy closure plug.

3. The soluble cementing grader according to claim 1, characterized in that: Both the first shear connector (5) and the second shear connector (6) are shear studs.

4. The soluble cementing grader according to claim 1, characterized in that: The retaining ring (9) is a sawtooth retaining ring.

5. The soluble cementing grader according to claim 1, characterized in that: The central tube (2) is connected to the soluble shut-off plug (10) by a set screw (12).

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