Soluble plunger

Abstract

The utility model discloses a soluble plunger, which relates to the technical field of oil and gas well fracturing, is hollow inside, has two closed ends, and comprises a front seat, an elastic tube and a rear seat which are sequentially in threaded connection, a plurality of elastic sheets are arrayed on the outer wall of the elastic tube along the circumferential direction, one end, facing the front seat, of each elastic sheet is an acute angle, and the other end of each elastic sheet is an obtuse angle. The two sides of the elastic piece are each provided with a strip-shaped groove, and the strip-shaped grooves penetrate through the side wall of the elastic pipe. According to the scheme, the soluble plunger is clamped in the sliding sleeve at the corresponding position through the elastic piece, and the opening and closing effect on the sliding sleeve is achieved; the pressure bearing level of the soluble plunger is 70 MPa.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas well fracturing, in particular to a soluble plunger. Background Art

[0002] In order to achieve multi-stage fracturing, accurately control the position of the fracturing sleeve, and reduce operating costs and complexity, a large-diameter fracturing sleeve system was developed and designed. The specific steps are as follows: multiple different casings are assembled into a sleeve, and the multiple sleeves are assembled in sequence according to a specific order; the multiple sleeves are lowered into the oil and gas layer in the well, and the inner wall of the sleeve has a groove, and the length of each sleeve groove decreases step by step from bottom to top; after cementing, the plungers are lowered in sequence according to a specific order, and the plungers are stuck in the corresponding sleeves; after pressure is applied to the plungers, the fracturing holes of the sleeves are opened, and multi-layer staged fracturing begins.

[0003] The problem is that the shape and size of the plunger required by the system must be compatible with the corresponding sleeve, be able to seal the sleeve, and be able to withstand sufficiently large pressure. The plungers in the existing technology cannot meet the requirements, so this solution designs a soluble plunger. Utility Model Content

[0004] In order to solve the deficiencies of the prior art, the utility model provides a soluble plunger that can be stuck in a corresponding sliding sleeve, is easy to construct, and can withstand high-level pressure.

[0005] In order to achieve the purpose of this utility model, the following scheme is proposed:

[0006] A soluble plunger is hollow inside and closed at both ends. It includes a front seat, an elastic tube, and a rear seat that are threadedly connected in sequence. The outer wall of the elastic tube is arranged with multiple elastic sheets in an array along the circumferential direction. The elastic sheet has an acute-angle structure at one end facing the front seat and an obtuse-angle structure at the other end. A strip groove is provided on each side of the elastic sheet, and the strip groove runs through the side wall of the elastic tube.

[0007] Furthermore, a plurality of elastic blocks are arrayed along the circumferential direction on the outer wall of the elastic tube. The number and position of the elastic blocks correspond to the elastic sheet one by one. The elastic block is located between the elastic sheet and the front seat, and one end of the strip groove is located between the elastic block and the front seat.

[0008] Furthermore, the soluble plunger is made of a soluble metal material.

[0009] Furthermore, one end of the elastic block facing the front seat is in an obtuse angle structure, and the other end is also in an obtuse angle structure.

[0010] Furthermore, the first end of the rear seat is closed, and the second end is threadedly connected to the inner wall of the elastic tube. The outer diameter of the first end of the rear seat is larger than the outer diameter of the elastic tube and smaller than the outer diameter of the elastic sheet.

[0011] Furthermore, the first end of the front seat is closed, the second end is threadedly connected to the inner wall of the elastic tube, and the first end of the front seat is rounded.

[0012] Furthermore, the outer wall of the elastic sheet is arc-shaped, and the center of the arc is located on the central axis of the elastic tube.

[0013] The beneficial effects of the present invention are:

[0014] 1. The soluble plunger has a pressure rating of 70 MPa and withstands pressure in two ways: one is through the elastic piece being stuck in the slot of the sliding sleeve, and the other is through the large-sized back seat being stuck in the sliding sleeve.

[0015] 2. The soluble plunger can be directly put into the well without the assistance of other equipment, which greatly saves costs.

[0016] 3. The sliding sleeve in the well is opened and closed by the soluble plunger. During the fracturing construction, only the soluble plunger remains in the wellbore, which can effectively reduce construction accidents.

[0017] 4. The soluble plunger is made of soluble metal. After fracturing is completed, the soluble plunger will be dissolved so that the diameter inside the sliding sleeve can be maintained, which is convenient for subsequent well repair operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A diagram of the soluble plunger structure is shown;

[0019] Figure 2 A cross-sectional view of a soluble plunger is shown;

[0020] Figure 3 A top view of a soluble plunger is shown;

[0021] Figure 4 A schematic diagram showing the soluble plunger being stuck in the sliding sleeve is shown. DETAILED DESCRIPTION

[0022] like Figure 1 As shown, this embodiment provides a soluble plunger, which is hollow inside and includes a front seat 73, an elastic tube 72 and a rear seat 71 that are threadedly connected in sequence, and the end surfaces of the front seat 73 and the rear seat 71 are both closed.

[0023] Specifically, such as Figure 1-Figure 3 As shown, the outer wall of the elastic tube 72 is arrayed with multiple elastic sheets 721 in the circumferential direction. The outer wall of the elastic sheet 721 is arc-shaped, and the center of the arc is located on the central axis of the elastic tube 72. The end of the elastic sheet 721 facing the front seat 73 is an acute-angle structure for hooking the corresponding slot of the sliding sleeve, and the other end of the elastic sheet 721 is an obtuse-angle structure. A strip groove 722 is provided on each side of the elastic sheet 721. The strip groove 722 runs through the side wall of the elastic tube 72. The function of the strip groove 722 is to ensure that the elastic tube 72 can undergo elastic deformation.

[0024] Specifically, such as Figure 1 、 Figure 2 As shown, the outer wall of the elastic tube 72 is further arrayed with a plurality of elastic blocks 723 along the circumferential direction. The number and position of the elastic blocks 723 correspond one-to-one to the elastic sheet 721. The outer wall of the elastic block 723 is also arc-shaped, and the center of the arc is also located on the central axis of the elastic tube 72. The elastic block 723 is located between the elastic sheet 721 and the front seat 73. One end of the elastic block 723 facing the front seat 73 is an obtuse-angle structure, and the other end is also an obtuse-angle structure. One end of the strip groove 722 is located between the elastic block 723 and the front seat 73.

[0025] Specifically, the first end of the rear seat 71 is closed, and the second end of the rear seat 71 is threadedly connected to the inner wall of the elastic tube 72 . The outer diameter of the first end of the rear seat 71 is larger than the outer diameter of the elastic tube 72 and smaller than the outer diameter of the elastic sheet 721 .

[0026] Figure 4 This is a schematic diagram of the soluble plunger being stuck in the corresponding sliding sleeve. When the soluble plunger is lowered into the well, in order to ensure that the soluble plunger can smoothly pass through the unmatched sliding sleeve and finally reach the matching sliding sleeve, the outer diameter of the back seat 71 of each soluble plunger increases step by step from bottom to top, and the outer diameter of the back seat 71 should be larger than the inner diameter of the corresponding casing in the corresponding sliding sleeve, so that the back seat 71 is stuck at the top of the corresponding casing in the corresponding sliding sleeve; in addition, the length of the elastic sheet 721 of each soluble plunger decreases step by step from bottom to top, so that the elastic sheet 721 is stuck in the card groove of the corresponding sliding sleeve.

[0027] The soluble plunger provided in this embodiment has a pressure rating of 70 MPa. This pressure is supported by two means: first, the elastic sheet 721 is retained within the corresponding sleeve's slot, and second, the large back seat 71 is retained against the top of the corresponding sleeve's sleeve. When retained against the top of the sleeve's sleeve, the large back seat 71 also seals the sleeve.

[0028] Specifically, the first end of the front seat 73 is closed, and the second end is threadedly connected to the inner wall of the elastic tube 72. The first end of the front seat 73 is rounded, and the front seat 73 plays a guiding role, making it easier to lower the soluble plunger to a specific position in the well.

[0029] Specifically, the soluble plunger is made of a soluble metal material, such as a magnesium-aluminum alloy. After the fracturing is completed, the soluble plunger is dissolved so that the diameter of the sleeve is still maintained, which is convenient for subsequent well repair operations.

[0030] The soluble plunger provided in this embodiment has the following performance advantages:

[0031] ①Adapt to different temperature ranges of 38℃~178℃ (100F-350F);

[0032] ② A variety of material combination designs can be provided to meet the requirements of different blocks;

[0033] ③ The pressure level is 70MPa (10,000PSI), the design is simple, and the integrated anti-premature setting design can be set in the sliding sleeve at a specific position;

[0034] ④100% metal soluble material, completely dissolved within 5 days (dissolution time can be adjusted according to site needs);

[0035] ⑤ Fine treatment of metal surface, surface coating treatment, acid-resistant, water-soluble, anti-corrosion surface spraying to adapt to the construction wells of acid injection immersion;

[0036] ⑥Applicable to all current casing steel grades (P110 / 125 / 140, etc.);

[0037] ⑦ The maximum inner diameter design is conducive to flowback after fracturing without affecting production.

[0038] The above embodiments are only used to illustrate the technical ideas and features of the present invention and are not intended to be exclusive or limitative of the present invention. It should be understood by those skilled in the art that various changes or equivalent replacements made to the present invention without departing from the scope of the present invention are within the scope of protection of the present invention.

Claims

1. A soluble plunger, characterized in that: It is hollow inside and closed at both ends, and comprises a front seat (73), an elastic tube (72) and a rear seat (71) which are threadedly connected in sequence; The outer wall of the elastic tube (72) is provided with a plurality of elastic sheets (721) arranged in an array along the circumferential direction. One end of the elastic sheet (721) facing the front seat (73) is in an acute angle structure, while the other end is in an obtuse angle structure. A strip groove (722) is provided on each side of the elastic sheet (721), and the strip groove (722) penetrates the side wall of the elastic tube (72).

2. The soluble plunger according to claim 1, wherein The outer wall of the elastic tube (72) is further provided with a plurality of elastic blocks (723) arranged in an array along the circumferential direction. The number and position of the elastic blocks (723) correspond to the elastic sheet (721) one by one. The elastic block (723) is located between the elastic sheet (721) and the front seat (73). One end of the strip groove (722) is located between the elastic block (723) and the front seat (73).

3. The soluble plunger according to claim 1, wherein The soluble plunger is made of soluble metal material.

4. The soluble plunger according to claim 1, wherein One end of the elastic block (723) facing the front seat (73) is in an obtuse angle structure, and the other end is also in an obtuse angle structure.

5. The soluble plunger according to claim 1, wherein The first end of the rear seat (71) is closed, and the second end is threadedly connected to the inner wall of the elastic tube (72). The outer diameter of the first end of the rear seat (71) is larger than the outer diameter of the elastic tube (72) and smaller than the outer diameter of the elastic sheet (721).

6. The soluble plunger according to claim 1, wherein: The first end of the front seat (73) is closed, the second end is threadedly connected to the inner wall of the elastic tube (72), and the first end of the front seat (73) is rounded.

7. The soluble plunger according to claim 1, wherein: The outer wall of the elastic sheet (721) is arc-shaped, and the center of the arc is located on the central axis of the elastic tube (72).

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