Repeatable opening and closing mechanism for intelligent fracturing sliding sleeve

Abstract

The utility model relates to the technical field of fracturing sliding sleeve opening and closing, in particular to a repeatable opening and closing mechanism for an intelligent fracturing sliding sleeve. In order to adapt to different working conditions and reduce the use of electrical elements, the following scheme is adopted: the device comprises an outer shell, a central pipe is detachably connected in the outer shell, a spring sleeves the central pipe, the upper end of the spring abuts against the inner part of the outer shell, a wedge-shaped pushing piece is inserted into the central pipe, and a guide rail, a clamping block and a guide rail are fixedly connected to the lower end of the wedge-shaped pushing piece; the transverse position of the clamping block can be changed while the clamping block can longitudinally slide relative to the guide rail; an inserting groove is formed in the outer wall of the center pipe, a pin hole is formed in the limiting ring, a shear pin fixedly connected to the limiting ring is arranged in the pin hole, and the shear pin is inserted into the inserting groove; a baffle ring located below the limiting ring is inserted into the outer shell, and the baffle ring is detachably connected with the center pipe. By means of a mechanical mechanism, the clamping block is used for opening the fracture or closing the sliding sleeve, and the reliability of underground work is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fracturing sleeve switches, and more specifically to a repeatable switch mechanism for an intelligent fracturing sleeve. Background Art

[0002] The horizontal well staged fracturing technology is an engineering technology that has developed along with the development of unconventional oil and gas such as shale gas, tight gas, and tight oil. At present, the most commonly used technology is the open hole horizontal well packer + sliding sleeve technology, which opens the fracturing sleeve by inserting balls of different diameters to implement fracturing operations. The current staged fracturing technology has shortcomings. It requires the insertion of balls of different diameters and ball seats to open the sleeve, and the number of staged levels is limited. The tubing cannot achieve full bore, which increases the friction resistance generated when the fracturing fluid flows in the tubing. The ball seat of the sleeve needs to be drilled out during subsequent well repair construction, which is complicated and increases the risk.

[0003] In order to overcome the shortcomings of existing fracturing technology, an infinite-stage fracturing sleeve was developed. Commonly used fracturing sleeves require the use of flying dart tools to pressurize and open the fracturing sleeve. The use of flying dart tools during fracturing is cumbersome and poses a safety hazard. In addition, due to the complex structure of flying dart tools, they often need to be combined with electrical components, which greatly reduces the working reliability in the high temperature and high pressure environment underground. Utility Model Content

[0004] The utility model provides a repeatable switch mechanism for an intelligent fracturing sleeve, which aims to open or close the fracturing sleeve by means of a mechanical mechanism, thereby improving the reliability of underground work.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A repeatable switch mechanism for an intelligent fracturing sliding sleeve comprises an outer shell, a center tube is detachably connected to the outer shell, a spring is sleeved on the center tube, the upper end of the spring is against the outer shell, a wedge-shaped push piece is plugged into the center tube, the spring provides elastic force to the wedge-shaped push piece, so that the wedge-shaped push piece has a tendency to move downward, a guide rail is fixedly connected to the lower end of the wedge-shaped push piece, a transverse opening is provided on the outer shell, a locking block is provided in the opening, a limit ring capable of longitudinal sliding is plugged into the outer shell, a transverse slideway is formed between the upper end surface of the limit ring and the upper edge of the outer shell opening, the locking block can slide transversely along the transverse slideway, the distance between the outer peripheral inclined surface of the guide rail and the axis of the outer shell increases from bottom to top, an inclined groove matching the guide rail is provided on the locking block, the guide rail is plugged in the inclined groove, so that the locking block can slide longitudinally relative to the guide rail;

[0007] A slot is provided on the outer wall of the central tube, a pin hole is provided in the limiting ring, a shear pin fixed to the limiting ring is provided in the pin hole, and the shear pin is inserted in the slot;

[0008] A retaining ring located below the limiting ring is inserted into the outer shell, and the retaining ring is detachably connected to the central tube.

[0009] The utility model has the following beneficial effects:

[0010] 1. The repeatable switch mechanism of the intelligent fracturing sleeve is brought into the well by the coiled tubing to open / close the specified fracturing sleeve, which improves the stability of the sleeve opening and also provides an effective means for closing the sleeve when plugging water.

[0011] 2. The utility model adopts a mechanical locking structure. When locking, the switch mechanism can be locked in the inner core of the fracturing sleeve without pressing the pipe string. The fracturing sleeve can be closed / opened by lifting or lowering the pipe string.

[0012] 3. After the locking block is retracted, it can be unlocked by lifting the pipe string, and it can be unloaded from the well with the oil pipe without other operating switch mechanisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of a repeatable switch mechanism for an intelligent fracturing sliding sleeve of the utility model;

[0014] Figure 2 for Figure 1 Sectional view at QQ;

[0015] Figure 3 A schematic diagram showing the shear pin being fixed in the inner core of the sliding sleeve;

[0016] Figure 4 This is a schematic diagram of opening the fracturing sliding sleeve of the utility model;

[0017] Figure 5 This is a schematic diagram of the closed fracturing sleeve of the utility model;

[0018] Figure 6 It is a schematic diagram of the retraction of the locking block;

[0019] Figure 7 This is a schematic diagram of the position of the locking block after the utility model is disengaged;

[0020] In the figure: A1, outer shell; A2, retaining ring; A3, limit ring; A4, shear pin; A5, locking block; A6, wedge-shaped push piece; A7, spring; A8, center tube; A9, continuous oil pipe; b1, inner core of sliding sleeve. DETAILED DESCRIPTION

[0021] A repeatable switch mechanism for intelligent fracturing sliding sleeve, reference Figure 1, comprising an outer shell A1, a first diameter-reduced section is provided on the upper side of the inner part of the outer shell A1 to form a first shoulder, so that the top of the central pipe A8 is connected to the first diameter-reduced section by threads, a second diameter-reduced section is provided inside the outer shell A1 to connect to the upper end of the first diameter-reduced section to form a second shoulder, so that the top of the coiled tubing A9 abuts against the lower end of the second shoulder, a third diameter-reduced section is provided inside the outer shell A1 to connect to the upper end of the second diameter-reduced section, and an internal thread is provided on the inner circumference of the outer shell A1 at the third diameter-reduced section for realizing a detachable connection with the coiled tubing A9 by threaded cooperation;

[0022] A spring A7 in a compressed state is sleeved on the central tube A8, and the upper end of the spring A7 abuts against the lower end of the first shoulder. A wedge-shaped push piece A6 is inserted into the central tube A8, and the lower end of the spring A7 abuts against the upper end of the wedge-shaped push piece A6. The spring A7 provides elastic force to the wedge-shaped push piece A6, so that the wedge-shaped push piece A6 has a tendency to move downward. The lower end of the wedge-shaped push piece A6 is fixedly connected with guide rails evenly distributed around the circumference. The number of guide rails is preferably four. For example, four guide rails evenly distributed around the circumference are provided on the outer shell A1. The outer shell A1 has an opening, in which a locking block A5 is arranged, and a limiting ring A3 capable of longitudinal sliding is inserted in the outer shell A1, and a transverse slideway is formed between the upper end surface of the limiting ring A3 and the upper edge of the opening of the outer shell A1, and the locking block A5 can slide transversely along the transverse slideway, and the distance between the outer peripheral inclined surface of the guide rail and the axis of the outer shell A1 increases from bottom to top, and an inclined groove matching the guide rail is arranged on the locking block A5, and the guide rail is inserted in the inclined groove, so that the locking block A5 can slide longitudinally relative to the guide rail, and the locking block A5 can slide longitudinally relative to the guide rail. Figure 7 When the wedge-shaped push piece A6 drives the guide rail to move upward, the guide rail pushes the locking block A5 to move toward the axis of the outer shell A1, so that the locking block A5 is retracted into the opening; when the wedge-shaped push piece A6 drives the guide rail to move downward, the guide rail drives the locking block A5 to move away from the axis of the outer shell A1, so that the locking block A5 is moved out of the opening;

[0023] A slot is provided on the outer wall of the center tube A8, and two mirror-symmetrical pin holes are provided in the limit ring A3. The pin holes are connected to the openings, and a shear pin A4 fixed to the limit ring A3 is provided in the pin holes, and the shear pin A4 is inserted in the slot;

[0024] A retaining ring A2 located below the opening and the limit ring A3 is inserted into the outer shell A1, the inner circumference of the retaining ring A2 is provided with an internal thread, the outer circumference of the lower end of the center tube A8 is provided with an external thread, the retaining ring A2 and the center tube A8 are detachably connected through threaded cooperation, the inner circumference of the retaining ring A2 is provided with an integrally connected fourth shoulder, the lower outer circumference of the center tube A8 is provided with an integrally connected fifth shoulder, and the upper end of the fourth shoulder is in contact with the lower end of the fifth shoulder.

[0025] refer to Figure 3 , 45. A mechanical locking structure is adopted. When locking, there is no need to pressurize the tubing string. The repeatable switch mechanism of the intelligent fracturing sleeve can be locked in the sleeve inner core b1 of the fracturing sleeve. A groove is provided on the inner wall of the sleeve inner core b1. The locking block A5 is extended and locked in the groove. At this time, the repeatable switch mechanism of the intelligent fracturing sleeve moves downward to drive the sleeve valve core b1 downward to open the sleeve. The repeatable switch mechanism of the intelligent fracturing sleeve moves upward to drive the sleeve valve core b1 upward to close the sleeve.

[0026] After the intelligent fracturing sleeve is fixed in the sleeve inner core b1 with a repeatable switch mechanism, the shear pin A4 is sheared by applying pressure to the tubing string, thereby opening the fracturing sleeve. The sleeve inner core b1 moves downward under the action of pressure to the limit position, at which time the fracturing sleeve is fully opened.

[0027] See also Figure 6 After the intelligent fracturing sleeve is opened and closed with the repeatable opening and closing mechanism, the coiled tubing A9 is lifted up. At this time, the shear pin A4 is sheared off by force. At this time, the limit ring A3 can move on the center pipe A8. The coiled tubing A9 is lifted up. The locking block A5 moves downward relative to the entire opening and closing mechanism under the action of the inner core b1 of the sleeve, pushing the limit ring A3 seat to move downward until it contacts the retaining ring A2 and stops moving.

Claims

1. A repeatable switch mechanism for an intelligent fracturing sleeve, comprising an outer shell (A1), a central tube (A8) being detachably connected to the outer shell (A1), characterized in that: A spring (A7) is sleeved on the central tube (A8), the upper end of the spring (A7) is against the outer shell (A1), a wedge-shaped push piece (A6) is inserted into the central tube (A8), the spring (A7) provides elastic force to the wedge-shaped push piece (A6), so that the wedge-shaped push piece (A6) has a tendency to move downward, and a guide rail is fixed to the lower end of the wedge-shaped push piece (A6), a transverse opening is provided on the outer shell (A1), a locking block (A5) is provided in the opening, and the outer shell (A1) 1) A limiting ring (A3) capable of longitudinal sliding is inserted therein, a transverse slideway is formed between the upper end surface of the limiting ring (A3) and the upper edge of the opening of the outer shell (A1), the locking block (A5) can slide transversely along the transverse slideway, the distance between the outer peripheral inclined surface of the guide rail and the axis of the outer shell (A1) increases from bottom to top, the locking block (A5) is provided with an inclined groove cooperating with the guide rail, the guide rail is inserted in the inclined groove, so that the locking block (A5) can slide longitudinally relative to the guide rail; A slot is provided on the outer wall of the central tube (A8), a pin hole is provided in the limiting ring (A3), a shear pin (A4) fixedly connected to the limiting ring (A3) is provided in the pin hole, and the shear pin (A4) is inserted into the slot; A retaining ring (A2) located below the limiting ring (A3) is inserted into the outer shell (A1), and the retaining ring (A2) is detachably connected to the central tube (A8).

2. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1 is characterized in that: A first reduced diameter section is provided on the upper side of the interior of the outer shell (A1) to form a first shoulder, so that the top of the central tube (A8) can be detachably connected in the first reduced diameter section, and the upper end of the spring (A7) abuts against the lower end of the first shoulder.

3. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 2 is characterized in that: The outer shell (A1) is provided with a second diameter-reducing section connected to the upper end of the first diameter-reducing section to form a second shoulder, so that the top of the coiled tubing (A9) abuts against the lower end of the second shoulder.

4. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 3 is characterized in that: A third diameter-reducing section connected to the upper end of the second diameter-reducing section is arranged inside the outer shell (A1).

5. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1 is characterized in that: The outer shell (A1) is provided with an internal thread on the inner circumference of the third reduced diameter section.

6. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1, characterized in that: There are four guide rails, the circumference of which is evenly distributed on the wedge-shaped push piece (A6), and each guide rail is matched with a locking block (A5).

7. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1, characterized in that: When the wedge-shaped push piece (A6) drives the guide rail to move upward, the guide rail drives the locking block (A5) to move toward the axis of the outer shell (A1), so that the locking block (A5) is retracted into the opening; when the wedge-shaped push piece (A6) drives the guide rail to move upward, the guide rail drives the locking block (A5) to move in a direction away from the axis of the outer shell (A1), so that the locking block (A5) is moved out of the opening.

8. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1, characterized in that: The number of the pin holes is two, and the two pin holes are arranged in mirror symmetry.

9. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1, characterized in that: The pin hole is in conduction with the opening.

10. The repeatable switch mechanism for the intelligent fracturing sleeve according to claim 1, characterized in that: The inner periphery of the retaining ring (A2) is provided with an integrally connected fourth shoulder, and the lower outer periphery of the central tube (A8) is provided with an integrally connected fifth shoulder, and the upper end of the fourth shoulder contacts the lower end of the fifth shoulder.

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