Multi-stage filtering high-pressure fracturing hydraulic anchor

Abstract

The utility model discloses a multi-stage filtering high-pressure fracturing hydraulic anchor which comprises a hydraulic anchor body, a plurality of anchor fluke cavities communicated with a center hole channel are formed in the middle section of the hydraulic anchor body, anchoring mechanisms are installed in the anchor fluke cavities respectively, an outer sleeve is embedded in a center hole of the hydraulic anchor body, and an inner sleeve is embedded in the outer sleeve. The upper end of the central hole of the hydraulic anchor body is embedded with a body upper sealing ring which is sealed with the outer wall of the upper part of the outer sleeve, and the lower end of the central hole of the hydraulic anchor body is embedded with a body lower sealing ring which is sealed with the outer wall of the lower part of the inner sleeve; a plurality of inner sleeve linear cutting seams are uniformly formed in the circumference of the upper part of the inner sleeve and are communicated with the inner wall gaps of the outer sleeve; and a plurality of outer sleeve linear cutting seams are uniformly formed in the circumference of the lower part of the outer sleeve and are communicated with the inner wall gaps of the central hole of the hydraulic anchor body. The hydraulic anchor is reliable in anchoring, has a multi-stage filtering and sand prevention function, and thoroughly avoids sand blockage during anchor releasing.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of hydraulic anchors, especially a kind of multistage filtration high-pressure fracturing hydraulic anchor, belong to oil and gas well hydraulic fracturing tool technical field. BACKGROUND

[0002] In the development process of oil and gas reservoir, tight oil and gas reservoir needs to be fractured and reconstructed, and the fracturing and reconstruction string usually needs to be installed with a hydraulic anchor. The hydraulic anchor in the string anchors the string, so that the entire string will not appear to creep during the construction process. While anchoring, the hydraulic anchor in the fracturing string must have sand prevention function to avoid the anchor claw from being unable to be recovered and sand sticking after the construction is completed, which leads to the entire string being unable to be smoothly pulled out.

[0003] The sand prevention pipe in the anchor body of the existing hydraulic anchor is a whole slotted pipe. The gap of the sand prevention pipe is between 0.2 and 0.3. The gap will increase under the influence of pressure in the well, and the fracturing sand will enter from the gap between the sand prevention pipe and the inner wall of the hydraulic anchor, which leads to the anchor claw hole being blocked when the anchor tooth is recovered due to the blocking of the fracturing sand, causing the anchor claw to be unable to be normally recovered, so that the operation string cannot be normally pulled out, and even the oil and water well needs to be overhauled. Another reason for the anchor claw to be unable to be normally recovered is that the spring recovery force is too small.

[0004] The reason why the anchor claw is not firmly anchored is that the direction of all anchor claws is perpendicular to the casing wall. In actual construction, the hydraulic anchor string is sometimes subjected to upward force and sometimes downward force, and the direction of the anchor claw is unreasonable.

[0005] The existing patent CN202220425984.8 sand prevention hydraulic anchor is composed of a pipe body I and a pipe body II. The pipe body I is directly inserted into the anchor body, and the pipe body II is threadedly connected with the anchor body. The up-and-down position gap of the pipe body I in the anchor body can be adjusted through the pipe body II according to different downhole environments. There is no effective sealing structure such as sealing ring, and the sand prevention is unreliable. Moreover, the anchor claw has only one direction.

[0006] The existing patent CN202021664552.X slotted sand prevention hydraulic anchor has a sand prevention pipe gap of 0.2-0.3. The gap will increase under the influence of pressure in the well, thereby causing sand blocking. Moreover, the anchor tooth cannot be normally recovered when it is recovered due to sand sticking, so that the operation string cannot be normally pulled out, and even the oil and water well needs to be overhauled. Moreover, the anchor claw has only one direction. CONTENT OF THE UTILITY MODEL

[0007] The purpose of this part is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part and the abstract of the specification and the utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0008] The utility model discloses a purpose at, overcome the problem in the prior art, provide a kind of multistage filtration high pressure fracturing hydraulic anchor, anchor reliable, and with multistage filtration sand prevention function, thoroughly avoid sand card when unanchoring.

[0009] To solve above technical problem, a kind of multistage filtration high pressure fracturing hydraulic anchor of the utility model, including hydraulic anchor body, the middle section of the hydraulic anchor body is equipped with multiple anchor claw cavities communicated with central hole, anchor claw cavity is respectively installed with anchoring mechanism, the central hole of the hydraulic anchor body is embedded with outer sleeve, the inner sleeve is nested in the outer sleeve, the upper and lower ends of the inner sleeve respectively exceed the port of outer sleeve, the upper end of the central hole of the hydraulic anchor body is embedded with the upper body seal ring and the upper outer wall of outer sleeve is sealed, the lower end of the central hole of the hydraulic anchor body is embedded with the lower body seal ring and the lower outer wall of inner sleeve is sealed, the upper circumference of the inner sleeve is uniformly equipped with multiple inner sleeve wire cutting slits and the inner wall gap of outer sleeve is communicated, the lower circumference of the outer sleeve is uniformly equipped with multiple outer sleeve wire cutting slits and the inner wall gap of the central hole of the hydraulic anchor body is communicated.

[0010] As the improvement of the utility model, the lower end of the inner sleeve abuts on the inner step of the central hole of the hydraulic anchor body, the outer wall of the upper end of the inner sleeve is expanded in diameter to form a large end of the inner sleeve, the lower part of the large end of the inner sleeve is provided with an outer taper surface of the large end of the inner sleeve, the outer taper surface of the large end of the inner sleeve is pressed on the horn mouth at the upper end of the central hole of the hydraulic anchor body, and each inner sleeve wire cutting slit extends to the top of the large end of the inner sleeve.

[0011] As a further improvement of the utility model, the top of the large end of the inner sleeve is a flat surface and a clip spring is pressed on top of it, and the clip spring is embedded in the inner wall ring groove of the central hole of the hydraulic anchor body.

[0012] As a further improvement of the utility model, the upper part of the outer sleeve abuts below the root of the large end of the inner sleeve, and the lower end of the outer sleeve abuts on the inner step of the central hole of the hydraulic anchor body.

[0013] As a further improvement of the utility model, the anchoring mechanism includes an anchoring piston, a pressing strip and a rectangular spring, the anchoring piston is embedded in the corresponding anchor claw cavity and is sealed from each other, the outer end surface of the anchoring piston is provided with anchor claw teeth on both sides, the rectangular spring is embedded in the center blind hole of the outer end surface of the anchoring piston, the outer end head of the rectangular spring abuts on the inner wall of the middle part of the pressing strip, and the upper and lower ends of the pressing strip are fixed on the hydraulic anchor body by fastening screws.

[0014] As a further improvement of the utility model, each said anchor jaw tooth is welded with a hard alloy tooth.

[0015] As a further improvement of the utility model, the anchor mechanism is provided with three groups along the height direction of the hydraulic anchor body, and the anchor jaw teeth of the three groups of anchor mechanisms are upward, central and downward from top to bottom.

[0016] As a further improvement of the utility model, the cooperation gap between the inner sleeve and the outer sleeve and the cooperation gap between the outer sleeve and the central hole of the hydraulic anchor body are H10 / d10 or H10 / c10.

[0017] As a further improvement of the utility model, the seam width of the inner sleeve wire cutting seam and the outer sleeve wire cutting seam is 0.2-0.3mm.

[0018] Compared with the prior art, the utility model has the following beneficial effects: 1, the inner sleeve and the outer sleeve are used to realize two-layer four-way filtration for sand prevention, the inner sleeve, the outer sleeve and the cooperation gap H10 / d10 or H10 / c10 between the outer sleeve and the central hole of the hydraulic anchor body, in the fracturing construction process, the pressure is increased, the liquid enters the gap between the inner sleeve and the outer sleeve from the inner sleeve wire cutting seam, then enters the gap between the inner wall of the hydraulic anchor body and the outer sleeve through the outer sleeve wire cutting seam, and then enters the anchor piston cavity, the liquid acts to push the anchor piston and the anchor sleeve. The double-layer filtration of the inner sleeve and the outer sleeve has good sand prevention effect.

[0019] 2, the anchor mechanism is designed as three groups, the anchor jaw teeth are upward, central and downward from top to bottom, and the anchoring effect is better. For the high-pressure fracturing well, in order to further improve the anchoring force of the hydraulic anchor, the hard alloy is welded on the anchor jaw, and since the hard alloy has high hardness, the anchoring force is greatly improved.

[0020] 3, the rectangular spring structure is used to increase the resilience of the anchor jaw of the hydraulic anchor, and the anchor jaw is easy to retract. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the drawings without creative labor, and the drawings are provided for reference and illustration only, not to limit the utility model. Among them:

[0022] Fig. 1 It is a sectional view of the multi-stage filtration high-pressure fracturing hydraulic anchor of the utility model;

[0023] Fig. 2 It is a cross-sectional view of the anchor mechanism embodiment one in the utility model;

[0024] Fig. 3 This is a cross-sectional view of Embodiment 2 of the anchoring mechanism in this utility model;

[0025] In the diagram: 1. Hydraulic anchor body; 1a. Upper sealing ring of the body; 1b. Lower sealing ring of the body;

[0026] 2. Snap ring;

[0027] 3. Outerwear; 3a. Outerwear seam cut;

[0028] 4. Inner sleeve; 4a. Inner sleeve seam cutting opening;

[0029] 5. Fastening screws; 6. Pressure strips; 7. Rectangular springs;

[0030] 8. Anchor piston; 8a. Piston seal ring;

[0031] 9. Anchor claw teeth; 10. Carbide teeth. Detailed Implementation

[0032] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0033] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0034] 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 is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] like Figs. 1 to 3 As shown, the multi-stage filtration high-pressure fracturing hydraulic anchor of this utility model includes: a hydraulic anchor body 1, a retaining spring 2, an outer sleeve 3, an inner sleeve 4, a fastening screw 5, a pressure strip 6, a rectangular spring 7, an anchoring piston 8, anchor claw teeth 9, and carbide teeth 10. The hydraulic anchor body 1 serves as the basic frame of the entire device and is used to install and fix other components.

[0036] The outer sleeve 3 is located in the center hole of the hydraulic anchor body, and the lower end of the outer sleeve 3 abuts against the inner step of the center hole of the hydraulic anchor body. The upper part of the center hole of the hydraulic anchor body is embedded with the upper body sealing ring 1a and the upper outer wall of the outer sleeve 3 to realize sealing between the outer wall of the outer sleeve 3 and achieve the sealing performance of the device.

[0037] The inner sleeve 4 abuts against the inner wall of the outer sleeve 3, the lower end of the inner sleeve 4 extends from the lower end of the outer sleeve 3 and abuts against the inner step of the center hole of the hydraulic anchor body, and the upper part of the center hole of the hydraulic anchor body is embedded with the lower body sealing ring 1b and the lower outer wall of the inner sleeve 4 to realize sealing. The upper outer wall of the inner sleeve 4 is expanded in diameter to form a large end of the inner sleeve, the lower part of the large end of the inner sleeve is provided with an outer taper surface of the large end of the inner sleeve, the outer taper surface of the large end of the inner sleeve is pressed on the bell mouth at the upper end of the center hole of the hydraulic anchor body, the top of the large end of the inner sleeve is a flat surface and is pressed by a circlip 2, the circlip 2 is embedded in the annular groove below the tapered female thread at the upper end of the hydraulic anchor body 1, and the upper part of the outer sleeve 3 abuts below the root of the large end of the inner sleeve. In this way, the inner sleeve 4 and the outer sleeve 3 are prevented from moving, and the stability of the assembly during operation is ensured.

[0038] A plurality of inner sleeve wire cutting slits 4a are uniformly arranged on the upper periphery of the inner sleeve 4, the slit width of each inner sleeve wire cutting slit 4a is 0.2-0.3mm, and the inner sleeve wire cutting slit 4a extends to the top of the large end of the inner sleeve 4, which is used to guide the liquid flow into the gap between the inner sleeve 4 and the outer sleeve 3.

[0039] A plurality of outer sleeve wire cutting slits 3a are uniformly arranged on the lower periphery of the outer sleeve 3, the slit width of each outer sleeve wire cutting slit 3a is 0.2-0.3mm, which is used to guide the liquid flow into the gap between the outer sleeve 3 and the inner wall of the center hole of the hydraulic anchor body. The inner and outer of the outer sleeve 3 are the hydraulic anchor body 1 and the inner sleeve 4 respectively. When the liquid enters, the outer sleeve 3 is limited by the inner and outer, which prevents the outer sleeve wire cutting slit 3a from expanding and limits the entry of the fracturing sand.

[0040] A plurality of anchor claw cavities communicating with the center channel are arranged on the periphery of the hydraulic anchor body 1, and an anchoring piston 8 is embedded in each anchor claw cavity. The circumferential wall of the anchoring piston 8 is embedded with a piston sealing ring 8a and the inner wall of the anchor claw cavity to realize sealing. A counterbore is arranged at the center of the outer end face of the anchoring piston 8, and a rectangular spring 7 is embedded in the counterbore. The outer end head of the rectangular spring 7 abuts against the inner wall of the middle part of the pressing strip 6. The pressing strip 6 extends along the axial direction of the hydraulic anchor body 1, and the upper and lower ends of the pressing strip 6 are fixed on the hydraulic anchor body 1 by fastening screws 5.

[0041] Anchor claw teeth 9 are arranged on both sides of the outer end face of the anchoring piston 8, and the pressing strip 6 is located between the two anchor claw teeth 9. When the center channel of the pipe string is pressurized, the liquid pushes the anchoring piston 8 to extend radially after multi-stage filtration, so that the anchor claw teeth 9 extend from both sides of the pressing strip 6 and are anchored to the inner wall of the sleeve.

[0042] The pressure strip 6 is used to press the outer end of the rectangular spring 7, which provides the resilience for the anchoring piston 8, ensuring that the anchoring jaw 9 can retract in time when the pressure changes, thereby releasing the anchoring.

[0043] For high-pressure fracturing wells, in order to further improve the anchoring force of the hydraulic anchor, hard alloy teeth 10 are welded on the anchoring jaw 9. Due to the high hardness and good wear resistance of the hard alloy, the friction between the anchoring jaw and the inner wall of the casing is greatly enhanced, thereby significantly improving the anchoring ability of the hydraulic anchor and ensuring stable anchoring under high pressure conditions.

[0044] The anchoring process is as follows: the sand-preventing hydraulic anchor is lowered into the well together with the fracturing string. When the string reaches the designed position, the fracturing operation begins. During the operation, when the pressure in the string reaches the setting pressure of the hydraulic anchor, the liquid pushes the anchoring piston 8 to automatically extend radially against the elastic force of the rectangular spring 7. The anchoring jaw 9 tightly clamps onto the inner wall of the casing, and the anchoring is achieved through the friction between the anchoring jaw and the casing, preventing the relative displacement between the tubing string and the casing.

[0045] The unseating process is as follows: after the fracturing operation is completed, when the pressure in the string decreases to less than the setting pressure of the hydraulic anchor, the anchoring piston 8 retracts under the action of the rectangular spring 7, and the hydraulic anchor is unseated, allowing the string to be smoothly pulled up.

[0046] Double-layer multi-channel filtration is achieved using the inner sleeve 4 and the outer sleeve 3. The fitting gap between the inner sleeve 4 and the outer sleeve 3 is H10 / d10 or H10 / c10, and the fitting gap between the outer sleeve 3 and the central hole of the hydraulic anchor body is also H10 / d10 or H10 / c10.

[0047] During the fracturing operation, the pressure in the central passage increases. After the liquid is filtered by the inner sleeve linear cutting seam 4a for the first time, it flows downward between the inner sleeve 4 and the outer sleeve 3 for the second time,

[0048] and then flows upward between the outer sleeve 3 and the central hole of the hydraulic anchor body for the fourth time, finally entering the anchoring jaw cavity to push the anchoring piston 8 and the anchoring jaw 9 to extend. The above design ensures that the liquid is filtered four times before entering the anchoring jaw cavity, effectively preventing impurities such as sand from entering the anchoring jaw cavity and protecting the normal operation of the anchoring jaw.

[0049] The anchoring jaw direction of the traditional hydraulic anchor is perpendicular to the inner wall of the casing, but in actual operation, the force direction of the hydraulic anchor string may be upward or downward, resulting in an unreasonable anchoring jaw direction. The anchoring mechanism of the present hydraulic anchor is designed as three groups, with the anchoring jaw teeth pointing upward, centrally, and downward from top to bottom. This multi-directional design enables the anchoring jaw to effectively anchor under different force conditions, significantly improving the anchoring effect.

[0050] The above merely describes preferred and feasible embodiments of the present application, shows and describes the basic principles, main features and advantages of the present application, and is not intended to limit the patent protection scope of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments. In addition to the above embodiments, the present application can also have other implementation manners without departing from the spirit and scope of the present application. The present application can also have various changes and improvements, and any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present application. The protection scope of the present application is defined by the appended claims and their equivalents. The technical features not described in the present application can be realized by or using the prior art, and will not be described here.

Claims

1. A multi-stage filtration high pressure fracturing hydraulic anchor, comprising a hydraulic anchor body, a middle section of the hydraulic anchor body is provided with a plurality of anchor claw cavities communicated with a central channel, and an anchoring mechanism is respectively installed in each anchor claw cavity, characterized in that: The outer sleeve is embedded in the center hole of the hydraulic anchor body, the inner sleeve is nested in the outer sleeve, the upper and lower ends of the inner sleeve respectively exceed the ports of the outer sleeve, the upper end of the center hole of the hydraulic anchor body is embedded with the upper sealing ring of the body and sealed with the upper outer wall of the outer sleeve, the lower end of the center hole of the hydraulic anchor body is embedded with the lower sealing ring of the body and sealed with the lower outer wall of the inner sleeve, the upper circumference of the inner sleeve is uniformly provided with a plurality of inner sleeve wire cutting slits which are communicated with the inner wall gap of the outer sleeve, and the lower circumference of the outer sleeve is uniformly provided with a plurality of outer sleeve wire cutting slits which are communicated with the inner wall gap of the center hole of the hydraulic anchor body.

2. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 1, wherein: The lower end of the inner sleeve abuts against the inner step of the center hole of the hydraulic anchor body, the upper end of the outer wall of the inner sleeve is expanded in diameter to form the large end of the inner sleeve, the lower part of the large end of the inner sleeve is provided with an outer taper surface of the large end of the inner sleeve, the outer taper surface of the large end of the inner sleeve is pressed on the bell mouth at the upper end of the center hole of the hydraulic anchor body, and each inner sleeve wire cutting slit extends to the top of the large end of the inner sleeve.

3. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 2, wherein: The top of the large end of the inner sleeve is a flat surface and is pressed from above by a snap spring, and the snap spring is embedded in the inner wall ring groove of the center hole of the hydraulic anchor body.

4. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 2, wherein: The upper part of the outer sleeve abuts below the root of the large end of the inner sleeve, and the lower end of the outer sleeve abuts against the inner step of the center hole of the hydraulic anchor body.

5. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 1, wherein: The anchoring mechanism comprises an anchoring piston, a pressing strip and a rectangular spring, the anchoring piston is embedded in the corresponding anchor jaw cavity and is sealed from each other, the outer end surface of the anchoring piston is provided with anchor jaw teeth on both sides, the rectangular spring is embedded in the center hole of the outer end surface of the anchoring piston, the outer end head of the rectangular spring abuts against the inner wall of the middle part of the pressing strip, and the upper and lower ends of the pressing strip are respectively fixed on the hydraulic anchor body by fastening screws.

6. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 5, wherein: Hard alloy teeth are respectively welded on each of the anchor jaw teeth.

7. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 5, wherein: The anchoring mechanism is provided with three groups in the height direction of the hydraulic anchor body, and the anchor jaw teeth of the three groups of anchoring mechanisms are respectively upward, central and downward from top to bottom.

8. The multi-stage filtered high pressure fracturing hydraulic anchor of claim 1, wherein: The cooperation gap between the inner sleeve and the outer sleeve and the cooperation gap between the outer sleeve and the center hole of the hydraulic anchor body are both H10 / d10 or H10 / c10.

9. The multi-stage filtered high-pressure fracturing hydraulic anchor according to any one of claims 1 to 8, characterized in that: The slit width of the inner sleeve wire cutting slit and the outer sleeve wire cutting slit is respectively 0.2-0.3mm.

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