Cementing and fracturing device, fracturing sliding sleeve and opening key

Abstract

The application provides a well cementation fracturing device, a fracturing sliding sleeve and an opening key, the well cementation fracturing device comprising a fracturing pipe column and an opening key; the fracturing pipe column comprising a float shoe, a float collar, a pressure-encountering seat and a fracturing sliding sleeve; the fracturing sliding sleeve comprising an upper joint, an outer cylinder, a lower joint and a sliding sleeve, the upper joint, the outer cylinder and the lower joint being sequentially connected from top to bottom, the side wall of the outer cylinder being provided with a fracturing hole, and the sliding sleeve being locked in the outer cylinder and blocking the fracturing hole; the inner wall of the sliding sleeve being provided with axially distributed upper and lower positioning grooves; at least one fracturing sliding sleeve being a stage sliding sleeve, the inner wall of the sliding sleeve of the stage sliding sleeve being provided with a locking groove; the outer wall of the opening key being provided with an upper positioning ring for cooperating with the upper positioning groove, a lower positioning ring for cooperating with the lower positioning groove and a locking ring for cooperating with the locking groove, and the opening key being capable of being elastically contracted inward. Through the application, the technical problem of low fracturing efficiency in segmented fracturing in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploitation devices, and particularly relates to a well cementation fracturing device, a fracturing sliding sleeve and an opening key. BACKGROUND

[0002] When an oil reservoir with abnormally high temperature, high pressure, low porosity and low permeability is exploited, high-deviation wells and horizontal wells are mainly used as production wells, and staged fracturing must be performed before production.

[0003] At present, a ball-drop type staged fracturing is generally used for casing completion. This fracturing method is beneficial to improving the flow conductivity of a reservoir and increasing the production of a production well or the injection of an injection well. However, the ball-drop type staged fracturing also has some disadvantages: (1) the ball-drop type staged fracturing technology needs to drop fracturing balls with different diameters into a pipe string. Due to the limitation of the diameter of the pipe string, the controllable fracturing stages are very limited, and it is difficult to meet the needs of the formation to be transformed; (2) the ball-drop type staged fracturing technology cannot realize high-displacement fracturing construction due to the restriction of the inner diameter of a tool, which affects the transformation effect and reduces the transformation scale; (3) the ball-drop type staged fracturing has poor targeting, and the construction cycle is long and the cost is high; (4) anchor shoe type tools are prone to downhole accidents such as card sealing and layer channeling; and (5) the perforation process is complex, and when the production reaches a certain degree, the opening degree is not perfect, and it is difficult to control the layer to be transformed. SUMMARY

[0004] The present application aims to provide a well cementation fracturing device, a fracturing sliding sleeve and an opening key to alleviate the technical problem of low fracturing efficiency of the staged fracturing in the prior art.

[0005] The above-mentioned technical problem of the present application can be solved by the following technical solutions.

[0006] The present application provides a well cementation fracturing device, which comprises a fracturing pipe string and an opening key for carrying a soluble ball.

[0007] The fracturing pipe string comprises a float shoe, a float collar, a pressure-encountering seat and a fracturing sliding sleeve.

[0008] The fracturing sliding sleeve comprises an upper joint, an outer cylinder, a lower joint and a sliding sleeve, the upper joint, the outer cylinder and the lower joint are connected in sequence from top to bottom, a side wall of the outer cylinder is provided with a fracturing hole, and the sliding sleeve is locked in the outer cylinder and blocks the fracturing hole.

[0009] An inner wall of the sliding sleeve is provided with axially distributed upper and lower positioning grooves, and an inner wall of the sliding sleeve of at least one stage sliding sleeve is provided with a locking groove.

[0010] The outer wall of the opening key is provided with an upper positioning ring for cooperating with the upper positioning groove, a lower positioning ring for cooperating with the lower positioning groove, and a locking ring for cooperating with the locking groove, and the opening key can be elastically contracted inward.

[0011] In a preferred embodiment, at least two of the fracturing sliding sleeves are cluster sliding sleeves, and the at least two cluster sliding sleeves are connected in sequence from top to bottom, the inner wall of the lowermost cluster sliding sleeve in the same cluster is provided with a locking groove; the cementing and fracturing device comprises a plurality of opening keys; the upper positioning ring and the lower positioning ring of the same opening key can match a plurality of cluster sliding sleeves in the same cluster; the upper positioning ring and the lower positioning ring of the opening key matched with the cluster sliding sleeve are different from the upper positioning ring and the lower positioning ring of the opening key matched with the stage sliding sleeve.

[0012] In a preferred embodiment, the distance between the upper positioning groove and the lower positioning groove in the plurality of cluster sliding sleeves in the same cluster is equal; the distance between the upper positioning groove and the lower positioning groove in the cluster sliding sleeve is different from the distance between the upper positioning groove and the lower positioning groove in the stage sliding sleeve.

[0013] In a preferred embodiment, the cluster sliding sleeve comprises a baffle installed on the fracturing hole, the baffle is provided with a baffle hole, and the baffle is configured to be eroded by fracturing medium.

[0014] In a preferred embodiment, the lower inner wall of the locking groove is inclined downward in a radially outward direction, and the lower wall of the locking ring is inclined downward in a radially outward direction.

[0015] In a preferred embodiment, the lower wall of the upper positioning ring is inclined upward in a radially outward direction, and the lower wall of the lower positioning ring is inclined upward in a radially outward direction.

[0016] In a preferred embodiment, the outer diameter of the upper positioning ring is greater than the outer diameter of the locking ring, and the outer diameter of the lower positioning ring is greater than the outer diameter of the locking ring.

[0017] In a preferred embodiment, the upper positioning ring, the locking ring, and the lower positioning ring are sequentially distributed from top to bottom.

[0018] The present application provides a fracturing sliding sleeve, comprising: an upper joint, an outer cylinder, a lower joint, and a sliding sleeve, the upper joint, the outer cylinder, and the lower joint are sequentially connected from top to bottom, the side wall of the outer cylinder is provided with a fracturing hole, and the sliding sleeve is locked in the outer cylinder and blocks the fracturing hole; the inner wall of the sliding sleeve is provided with an axially distributed upper positioning groove and a lower positioning groove.

[0019] The present invention provides an opening key, which has a bearing portion for carrying a soluble ball; the opening key can be inserted into the fracturing sleeve mentioned above, and the outer wall of the opening key is provided with an upper positioning ring, a lower positioning ring and a locking ring, the upper positioning ring is used to cooperate with the upper positioning groove, the lower positioning ring is used to cooperate with the lower positioning groove, and the opening key can elastically retract inward.

[0020] The features and advantages of this invention are:

[0021] This cementing and fracturing device can be equipped with multiple stages of sliding sleeves, with multiple opening keys corresponding to each stage. Unlike the ball-drop fracturing process, the inner diameters of the multiple stages of sliding sleeves in this cementing and fracturing device do not need to be set in a gradually decreasing manner from top to bottom. Therefore, the number of fracturing stages in this cementing and fracturing device is not limited by the inner diameter of the tubing string, enabling unlimited fracturing stages; furthermore, the tubing diameter does not need to gradually decrease downwards, resulting in a larger operational displacement; this cementing and fracturing device also has advantages such as high fracturing efficiency, high tool reliability, ease of operation, safety and environmental friendliness, adaptability to high-temperature environments, and low construction risk. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the fracturing tubing string in the cementing and fracturing device provided by the present invention.

[0024] Figure 2 for Figure 1 The diagram shows the structure of the primary sliding sleeve in the fracturing tubing string;

[0025] Figures 3-4 for Figure 1 The diagram shows the structure of the clustered sliding sleeve in the fracturing tubing string.

[0026] Figure 5 for Figure 3 The diagram shows the structure of the baffle in the cluster sliding sleeve;

[0027] Figure 6 for Figure 5 The left view;

[0028] Figure 7 for Figure 5 A bottom view;

[0029] Figure 8 A schematic diagram of the opening key in the cementing and fracturing device provided by the present invention;

[0030] Figure 9 is a partial enlarged view of B in Figure 8

[0031] Figure 10 is a partial enlarged view of A in Figure 2

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 11, float shoe; 12, float collar; 13, pressure seat; 14, casing; 15, cementing sliding sleeve;

[0034] 20, fracturing sliding sleeve; 21, stage sliding sleeve; 22, cluster sliding sleeve;

[0035] 31, upper joint; 32, outer cylinder; 321, fracturing hole; 322, locking ring; 323, retreat stop ring; 33, lower joint; 34, transition joint; 35, baffle; 351, baffle hole;

[0036] 40, sliding sleeve; 41, upper positioning groove; 42, lower positioning groove; 43, locking groove; 431, lower inner wall of locking groove;

[0037] 50, opening key; 501, bearing part; 502, axial groove;

[0038] 51, upper positioning ring; 52, lower positioning ring; 53, locking ring; 531, lower wall of locking ring. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0040] Scheme one

[0041] The present application provides a cementing and fracturing device, which comprises a fracturing pipe column and an opening key 50 for bearing a soluble ball, as shown in Figure 1 ​​As shown, the fracturing pipe string comprises a float shoe 11, a float collar 12, a pressure-encountering seat 13 and a fracturing sliding sleeve 20; the fracturing sliding sleeve 20 comprises an upper joint 31, an outer cylinder 32 and a lower joint 33, which are connected in sequence from top to bottom, and the side wall of the outer cylinder 32 is provided with a fracturing hole 321, and the sliding sleeve 40 is locked in the outer cylinder 32 and blocks the fracturing hole 321; the inner wall of the sliding sleeve 40 is provided with axially distributed upper positioning grooves 41 and lower positioning grooves 42; at least one fracturing sliding sleeve 20 is a stage sliding sleeve 21, as shown in Figure 2 As shown, the inner wall of the sliding sleeve 40 of the stage sliding sleeve 21 is provided with a locking groove 43; as shown in Figure 8 As shown, the outer wall of the opening key 50 is provided with an upper positioning ring 51 for cooperating with the upper positioning grooves 41, a lower positioning ring 52 for cooperating with the lower positioning grooves 42 and a locking ring 53 for cooperating with the locking groove 43, and the opening key 50 can be elastically deformed inwardly.

[0042] The soluble ball is placed on the top of the opening key 50, and the soluble ball and the opening key 50 are put into the fracturing pipe string together, the opening key 50 is elastically deformed inwardly under pressure, the opening key 50 moves to the stage sliding sleeve 21 matched therewith, the upper positioning ring 51 and the lower positioning ring 52 on the opening key 50 enter the upper positioning grooves 41 and the lower positioning grooves 42 of the stage sliding sleeve 21 matched therewith respectively, and at the same time, the locking ring 53 enters the locking groove 43, thereby locking the opening key 50 and the soluble ball. Through pressure holding, the soluble ball and the opening key 50 drive the sliding sleeve 40 to move downwardly, thereby opening the stage sliding sleeve 21 matched with the opening key 50, and fracturing construction is performed on the corresponding layer.

[0043] In the cementing and fracturing device, when the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53 on the opening key 50 are matched with the upper positioning grooves 41, the lower positioning grooves 42 and the locking groove 43 on the fracturing sliding sleeve 20, the opening key 50 is locked with the sliding sleeve 40 in the fracturing sliding sleeve 20, and by adjusting the setting form of the upper positioning grooves 41, the lower positioning grooves 42 and the locking groove 43 on the fracturing sliding sleeve 20, the locking position of the opening key 50 can be controlled, thereby controlling the layer of fracturing.

[0044] The well cementation and fracturing device can be provided with multiple stage sliding sleeves 21, and multiple opening keys 50 correspond to the stage sliding sleeves 21. In the ball-drop staged fracturing process, the pipe diameters of the sliding sleeves gradually decrease from top to bottom, so that the soluble balls of different diameters are locked in the sliding sleeves of different layers. Unlike the ball-drop staged fracturing process, the inner diameters of the multiple stage sliding sleeves 21 in the well cementation and fracturing device do not need to be gradually reduced from top to bottom. Therefore, the fracturing stages of the well cementation and fracturing device are not limited by the inner diameters of the pipe strings, and unlimited-stage fracturing can be achieved; and the pipe diameters and the pipe diameters do not need to be gradually reduced downward, and the construction discharge is relatively large; the well cementation and fracturing device also has the advantages of high fracturing efficiency, high tool reliability, easy operation, safety and environmental protection, adaptation to high-temperature environment, and low construction risk.

[0045] As shown in Figure 1 The float shoe 11, the float collar 12, the pressure-encountering seat 13, and the fracturing sliding sleeve 20 are sequentially distributed from bottom to top, and are connected through the casing 14 between adjacent ones.

[0046] In an embodiment, at least two fracturing sliding sleeves 20 are cluster sliding sleeves 22, and the at least two cluster sliding sleeves 22 are sequentially connected from top to bottom, and only the inner wall of the sliding sleeve 40 of the lowermost cluster sliding sleeve 22 in the same cluster is provided with the locking groove 43.

[0047] The well cementation and fracturing device includes multiple opening keys 50, each stage sliding sleeve 21 has a unique opening key 50 corresponding thereto, and each cluster of cluster sliding sleeves 22 also has a unique opening key 50 corresponding to the cluster. The upper positioning ring 51 and the lower positioning ring 52 of the same opening key 50 can match the multiple cluster sliding sleeves 22 in the same cluster; the upper positioning ring 51 and the lower positioning ring 52 of the opening key 50 matched with the cluster sliding sleeve 22 are different from the upper positioning ring 51 and the lower positioning ring 52 of the opening key 50 matched with the stage sliding sleeve 21.

[0048] The upper positioning groove 41 and the lower positioning groove 42 of the multiple cluster sliding sleeves 22 in the same cluster are arranged in the same way, so that the same opening key 50 can match the multiple cluster sliding sleeves 22 in the same cluster. The upper positioning groove 41 and the lower positioning groove 42 of the cluster sliding sleeve 22 are arranged in a different way from the upper positioning groove 41 and the lower positioning groove 42 of the stage sliding sleeve 21, so that the stage sliding sleeve 21 and the cluster sliding sleeve 22 need to be opened by different opening keys 50.

[0049] Only the lowermost cluster sleeve 22 in the same cluster of cluster sleeves 22 is provided with a locking groove 43. When the opening key 50 moves to the cluster sleeve 22 above, the upper positioning ring 51 and the lower positioning ring 52 enter the upper positioning groove 41 and the lower positioning groove 42 of the cluster sleeve 22 above, respectively. Since the cluster sleeve 22 above is not provided with a locking groove 43 matched with the locking ring 53, the opening key 50 and the cluster sleeve 22 above are semi-locked. Pressurization in the fracturing string is achieved by transmitting power to the sliding sleeve 40 through the upper positioning ring 51 and the lower positioning ring 52, and the dissolvable ball and the opening key 50 drive the sliding sleeve 40 to move downward, thereby opening the cluster sleeve 22 above. Increasing the discharge capacity in the fracturing string, the upper positioning ring 51 and the lower positioning ring 52 are separated from the upper positioning groove 41 and the lower positioning groove 42, respectively, and the semi-locked state between the opening key 50 and the cluster sleeve 22 is released. The opening key 50 and the dissolvable ball can continue to move downward, thereby sequentially opening each cluster sleeve 22 downward. When the opening key 50 moves to the lowermost cluster sleeve 22, the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53 of the opening key 50 enter the upper positioning groove 41, the lower positioning groove 42 and the locking groove 43 of the lowermost cluster sleeve 22, respectively. The opening key 50 and the cluster sleeve 22 are locked, thereby opening the lowermost cluster sleeve 22 and performing fracturing construction on each cluster sleeve 22 in the same cluster and the corresponding layer. The fracturing operation is more flexible and convenient to operate.

[0050] The cementing and fracturing device can include a plurality of stage sleeves 21 or a plurality of cluster sleeves 22. The upper positioning groove 41 and the lower positioning groove 42 of each stage sleeve 21 and the upper positioning groove 41 and the lower positioning groove 42 of each cluster sleeve 22 are different from each other, so that one opening key 50 can only open one corresponding stage sleeve 21 or one cluster sleeve 22.

[0051] The sliding sleeve 40 of the fracturing sleeve 20 is provided with the upper positioning groove 41 and the lower positioning groove 42. When the setting mode of the upper positioning ring 51 and the lower positioning ring 52 on the opening key 50 is matched with the setting mode of the upper positioning groove 41 and the lower positioning groove 42 of the fracturing sleeve 20, the opening key 50 can push the sliding sleeve 40 to move downward and open the fracturing sleeve 20 by transmitting force through the upper positioning ring 51 and the lower positioning ring 52.

[0052] For the stage sleeve 21 and the cluster sleeve 22 provided with the locking groove 43, when the setting mode of the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53 on the opening key 50 is matched with the setting mode of the upper positioning groove 41, the lower positioning groove 42 and the locking groove 43 of the fracturing sleeve 20, the opening key 50 can push the sliding sleeve 40 to move downward and open the fracturing sleeve 20, thereby performing fracturing construction.

[0053] For the clustered sliding sleeve 22 without a locking groove 43, after the sliding sleeve 40 is pushed down by the opening key 50 and the clustered sliding sleeve 22 is opened, since the pressure inside the tubing during fracturing is greater than the pressure required to push the sliding sleeve 40 down, by increasing the pressure inside the tubing or increasing the displacement, the upper positioning ring 51 and the lower positioning ring 52 can be disengaged from the upper positioning groove 41 and the lower positioning groove 42 respectively, thereby disengaging the opening key 50 from the clustered sliding sleeve 22, and the opening key 50 continues to move down.

[0054] The setting method of the upper positioning ring 51 and the lower positioning ring 52 includes parameters such as the shape and size of the upper positioning ring 51, the shape and size of the lower positioning ring 52, and the relative position and distance between the upper positioning ring 51 and the lower positioning ring 52. The setting method of the upper positioning ring 51 and the lower positioning ring 52 is the same, which means that all the above parameters are the same or compatible.

[0055] The setting method of the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53 includes parameters such as the shape and size of the upper positioning ring 51, the shape and size of the lower positioning ring 52, the shape and size of the locking ring 53, and the relative position and distance of the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53. The setting method of the upper positioning ring 51, the lower positioning ring 52 and the locking ring 53 being the same or compatible means that all the above parameters are the same or compatible.

[0056] Furthermore, the arrangement of the upper positioning ring 51 and the lower positioning ring 52 can be adjusted by controlling the distance between them. For example... Figure 2 , Figure 4 and Figure 8 As shown, when the upper positioning ring 51 and lower positioning ring 52 of the opening key 50 enter the upper positioning groove 41 and lower positioning groove 42 of the fracturing sleeve 20 respectively, the opening key 50 rebounds outward under its own elasticity, and the locking ring 53 returns to its original outer diameter size, locking in the locking groove 43 of the fracturing sleeve 20, ensuring that the fracturing operation of this section can be carried out. Preferably, in each stage of the sleeve 21, the distance between the upper positioning groove 41 and the lower positioning groove 42 is in an arithmetic sequence, increasing from bottom to top; correspondingly, the distance between the upper positioning ring 51 and the lower positioning ring 52 of the opening key 50 is also in this manner.

[0057] The distance between the upper positioning groove 41 and the lower positioning groove 42 in the first-stage fracturing sliding sleeve 20 is denoted as X, and the distance between the upper positioning ring 51 and the lower positioning ring 52 in the opening key 50 matched with the first-stage fracturing sliding sleeve 20 is also X. The distance between the upper positioning groove 41 and the lower positioning groove 42 in the second-stage fracturing sliding sleeve 20 is increased or decreased by a distance from X, for example, the distance between the upper positioning groove 41 and the lower positioning groove 42 in the second-stage fracturing sliding sleeve 20 and the distance between the upper positioning ring 51 and the lower positioning ring 52 in the opening key 50 matched with the second-stage fracturing sliding sleeve 20 are both (X+60) mm; the distance of the third-stage fracturing sliding sleeve is (X+120) mm, and so on. The inner diameters of the strings do not need to be decreased successively, and the matching of the axial distances can be used to control which fracturing sliding sleeve 20 is matched with the opening key 50, so that the design of unlimited stages can be realized.

[0058] In an embodiment, the distances between the upper positioning groove 41 and the lower positioning groove 42 in the plurality of cluster sliding sleeves 22 in the same cluster are equal; the distances between the upper positioning groove 41 and the lower positioning groove 42 in the cluster sliding sleeves 22 are different from the distances between the upper positioning groove 41 and the lower positioning groove 42 in the stage sliding sleeves 21. The plurality of cluster sliding sleeves 22 in the same cluster use one opening key 50 to open, so the distances between the two positioning grooves in each cluster sliding sleeve 22 are the same. Only the lowermost cluster sliding sleeve 22 in the plurality of cluster sliding sleeves 22 is provided with a locking groove 43 corresponding to the locking ring 53 of the opening key 50.

[0059] The cementing and fracturing device includes a plurality of stage sliding sleeves 21 and a plurality of cluster sliding sleeves 22, and the plurality of cluster sliding sleeves 22 in the same cluster form one stage. The distances between the upper positioning groove 41 and the lower positioning groove 42 in each stage sliding sleeve 21 and each cluster sliding sleeve 22 are also different.

[0060] In an embodiment, the cluster sliding sleeve 22 includes a baffle 35 installed on the fracturing hole 321, as shown in FIGS. 1 and 2, the baffle 35 is provided with a baffle hole 351, and the baffle 35 is configured to be eroded by the fracturing medium. Figure 3 and Figures 5-7 The upper cluster sliding sleeve 22 in the same cluster is opened first, and the opening key 50 is moved to the lower cluster sliding sleeve 22. At this time, the fracturing hole 321 of the upper cluster sliding sleeve 22 is blocked by the baffle 35, only a small amount of fluid flows out through the baffle hole 351, the pressure in the string is large, and the flow rate to the next cluster sliding sleeve 22 is large, which is beneficial to the opening of the lower cluster sliding sleeve 22 by the opening key 50. After each cluster sliding sleeve 22 in the same cluster is opened, the fracturing sand can quickly erode the baffle 35 in the low sand ratio stage in the early stage of fracturing, increase the flow area, and ensure that the fracturing medium flows to the formation through the fracturing hole 321 to perform fracturing.

[0061] As shown in FIG. 3, the fracturing sliding sleeve 20 is provided with a locking groove 43 corresponding to the locking ring 53 of the opening key 50. Figures 5-7As shown, the baffle 35 is in the shape of an arc plate, and a plurality of baffles 35 are uniformly distributed on the circumference of the outer cylinder 32 of the cluster sliding sleeve 22. The baffle 35 is made of soft and non-wear-resistant non-ferrous metal material, which can be eroded by the fracturing sand during fracturing operation, for example, an aluminum alloy material can be used.

[0062] As shown, Figures 2-4 The fracturing sliding sleeve 20 includes a locking ring 322 installed outside the outer cylinder 32. The outer cylinder 32 is connected with the lower joint 33 through a transition joint 34. The outer cylinder 32 is provided with a stop ring 323 between the outer cylinder 32 and the sliding sleeve 40. The sliding sleeve 40 and the outer cylinder 32 can be connected by a shear pin, which locks the sliding sleeve 40 on the outer cylinder 32. After the shear pin is cut, the sliding sleeve 40 can slide in the outer cylinder 32. As shown, Figure 3 and Figure 4 The baffle 35 is arranged inside the locking ring 322.

[0063] After the locking ring 53 enters the locking groove 43, the opening key 50 is locked with the fracturing sliding sleeve 20, and the opening key 50 and the fracturing sliding sleeve 20 can be locked under the action of a relatively large force. In an embodiment, as shown, Figure 2 and Figure 10 The lower inner wall 431 of the locking groove is inclined downward in the radial outward direction, as shown, Figure 8 and Figure 9 The lower wall 531 of the locking ring is inclined downward in the radial outward direction, forming an inverse bevel, and the lower wall 531 of the locking ring abuts against the lower inner wall 431 of the locking groove, so that when the opening key 50 is subjected to a downward force, the locking ring 53 cannot be separated from the locking groove 43. The included angle between the lower wall 531 of the locking ring and the axis of the opening key 50 is denoted as β, and preferably, the included angle between the lower inner wall 431 of the locking groove and the axis of the fracturing sliding sleeve 20 is also equal to β, and more preferably, β = 80°.

[0064] In an embodiment, as shown, Figure 8 The lower wall of the upper positioning ring 51 is inclined upward in the radial outward direction, and the lower wall of the lower positioning ring 52 is inclined upward in the radial outward direction. The opening key 50 can pass through the upper positioning ring 51 and the lower positioning ring 52, push the sliding sleeve 40 downward to open the cluster sliding sleeve 22, and when the downward force on the opening key 50 is further increased, the upper positioning ring 51 can slide out of the upper positioning groove 41, and the lower positioning ring 52 can slide out of the lower positioning groove 42, so as to ensure that the opening key 50 and the cluster sliding sleeve 22 are smoothly separated. After the cluster sliding sleeve 21 is opened by the corresponding opening key 50, under the action of the locking groove 43 and the inverse bevel of the locking ring 53, the opening key 50 cannot continue to move downward even under the action of pressure.

[0065] In one embodiment, the outer diameter of the upper positioning ring 51 is larger than the outer diameter of the locking ring 53, and the outer diameter of the lower positioning ring 52 is larger than the outer diameter of the locking ring 53. This ensures that when the upper positioning groove 41 and the lower positioning groove 42 of the fracturing sleeve 20 do not match the upper positioning ring 51 and the lower positioning ring 52 of the unlocking key 50, the locking ring 53 will not enter the locking groove 43. Furthermore, the upper positioning ring 51, the locking ring 53, and the lower positioning ring 52 are distributed sequentially from top to bottom.

[0066] like Figure 8 As shown, the side wall of the key 50 is provided with an axial groove 502 so that the key 50 can be elastically deformed inward under pressure in the column, ensuring that the key 50 moves smoothly in the column.

[0067] like Figure 8 As shown, the key 50 can be cylindrical. In one embodiment, the key 50 is provided with a support portion 501 for carrying a soluble ball, and the support portion 501 can be spherical.

[0068] In another embodiment, the key 50 is integrated with the soluble ball.

[0069] like Figure 1 As shown, the fracturing string includes a cementing sleeve 15. This cementing fracturing device can include multiple stage sleeves 21 and multiple cluster sleeves 22. Taking a four-stage fracturing operation as an example, the second and fourth stages are single clusters using stage sleeves 21; the third stage has three clusters using cluster sleeves 22. The fracturing string, from bottom to top, consists of: float shoe 11, casing 14, float collar 12, casing 14, pressure seat 13, casing 14, first-stage sleeve, casing 14, first cluster sleeve, casing 14, second cluster sleeve, casing 14, third cluster sleeve, casing 14, second-stage sleeve, and casing 14. The first cluster sleeve, second cluster sleeve, and third cluster sleeve are in the same cluster, forming a first stage. This cementing fracturing device can perform fracturing segment by segment from bottom to top. The construction steps include:

[0070] (1) Lower the perforation gun to perform perforation operation;

[0071] (2) Take out the perforating gun and carry out the first stage of fracturing;

[0072] (3) After the first stage of construction is completed, the first opening key and soluble ball are put in and pumped to the first-stage sliding sleeve; the casing 14 is pressurized to 15MPa, the first-stage sliding sleeve is opened, and the second stage of fracturing construction is carried out.

[0073] (4) After the second stage of fracturing is completed, the second opening key and soluble ball are inserted and pumped to the third cluster of sliding sleeves;

[0074] (5) Pressurize sleeve 14 to 15MPa and open the third sliding sleeve;

[0075] (6) Increase the pump displacement, send the second opening key and soluble ball to the second cluster sliding sleeve;

[0076] (7) The casing 14 is pressurized to 15 MPa, the second cluster sliding sleeve is opened, and then the third section 3-cluster fracturing operation is carried out;

[0077] (8) Continue to increase the pump displacement, send the second opening key and soluble ball to the first cluster sliding sleeve;

[0078] (9) The casing 14 is pressurized to 15 MPa, the first cluster sliding sleeve is opened, and then the third section 3-cluster fracturing operation is carried out;

[0079] (10) After the third section operation is completed, the third opening key and the soluble ball are put in and pumped to the second stage sliding sleeve;

[0080] (11) The casing 14 is pressurized to 15 MPa, the second stage sliding sleeve is opened, and then the fourth section fracturing operation is carried out;

[0081] (12) After the fourth section fracturing operation is completed, the special fishing tool is lowered to fish out all the opening keys 50, and the full bore of the wellbore is realized.

[0082] The cementing and fracturing device can be used as a fracturing tool for oil and gas exploitation in oil fields, and can be applied to the exploitation of oil, gas and water from horizontal wells, highly deviated wells or straight wells. The cementing and fracturing device has the following characteristics:

[0083] (1) The number of fracturing sections is not limited, and any number of sections can be completed by multiple trips of the pipe string from bottom to top, improving the operation efficiency and reducing the operation cost;

[0084] (2) Multiple cluster fracturing operations can be carried out in each section to more finely transform the formation;

[0085] (3) Large displacement operation can be carried out, which is suitable for volume fracturing, and the formation transformation is more thorough;

[0086] (4) The stress field of the near wellbore formation is changed, the compaction effect caused by high stress is removed, the permeability around the well is improved, the blockage is removed, the breakdown pressure is greatly reduced, under the action of tensile stress and micro-fracture network, the complexity of the fracturing fracture network is increased, and the single-stage single-well capacity is improved;

[0087] (5) Replace the original explosive perforating process, compared with the conventional perforation, it solves the problems of insufficient perforation depth, perforation compaction zone and pollution, and increases the contact area;

[0088] (6) The impact on the casing 14 and the cement sheath when opening the oil and gas layer is small, which can greatly reduce the damage to the cement sheath, is beneficial to maintaining the cementing quality, and has special significance for the development of thin layers.

[0089] Scheme two

[0090] The present application provides a fracturing sliding sleeve 20, comprising: an upper joint 31, an outer cylinder 32, a lower joint 33 and a sliding sleeve 40, the upper joint 31, the outer cylinder 32 and the lower joint 33 are connected in turn from top to bottom, the side wall of the outer cylinder 32 is provided with a fracturing hole 321, and the sliding sleeve 40 is locked in the outer cylinder 32 and blocks the fracturing hole 321; the inner wall of the sliding sleeve 40 is provided with an upper positioning groove 41 and a lower positioning groove 42 distributed in the axial direction.

[0091] A plurality of the fracturing sliding sleeve 20 can form multiple stages, unlike the ball-drop staged fracturing process, the inner diameter of the fracturing sliding sleeve 20 does not need to be arranged in a gradually decreasing manner from top to bottom, the fracturing stage number is not limited by the inner diameter of the pipe string, and unlimited stage fracturing can be realized; and the pipe diameter and the through diameter do not need to be gradually reduced downward, and the construction displacement is relatively large; the fracturing efficiency is high, the tool reliability is high, the operation is convenient, the safety is environmental protection, the high-temperature environment is adapted, and the construction risk is low.

[0092] Scheme three

[0093] The present application provides an opening key 50, the opening key 50 is provided with a bearing part 501 for bearing a soluble ball; the opening key 50 can be arranged in the fracturing sliding sleeve 20, the outer wall of the opening key 50 is provided with an upper positioning ring 51, a lower positioning ring 52 and a locking ring 53, the upper positioning ring 51 is used for cooperating with the upper positioning groove 41, the lower positioning ring 52 is used for cooperating with the lower positioning groove 42, and the opening key 50 can be elastically contracted inward.

[0094] The soluble ball is placed at the top of the opening key 50, the soluble ball and the opening key 50 are put into the fracturing pipe string together, the opening key 50 is elastically deformed inward under the extrusion, the opening key 50 moves to the matching fracturing sliding sleeve 20, the upper positioning ring 51 and the lower positioning ring 52 on the opening key 50 enter the upper positioning groove 41 and the lower positioning groove 42 of the matching fracturing sliding sleeve 20 respectively, and the locking ring 53 enters the locking groove 43, so as to lock the opening key 50 and the soluble ball. Through pressure holding, the soluble ball and the opening key 50 drive the sliding sleeve 40 to move downward, so as to open the stage sliding sleeve 21 matched with the opening key 50, and the corresponding layer is fractured, so that the fracturing stage number is not limited by the inner diameter of the pipe string, and unlimited stage fracturing can be realized; and the pipe diameter and the through diameter do not need to be gradually reduced downward, and the construction displacement is relatively large; the fracturing efficiency is high, the tool reliability is high, the operation is convenient, the safety is environmental protection, the high-temperature environment is adapted, and the construction risk is low.

[0095] The above only describes several embodiments of the present application, and those skilled in the art can make various modifications or changes to the embodiments of the present application according to the disclosed content of the application file without departing from the spirit and scope of the present application.

Claims

1. A cement fracturing device, characterized in that, The application relates to a fracturing string and a plurality of opening keys for carrying soluble balls. The fracturing string comprises a float shoe, a float collar, a pressure-encountering seat and a fracturing sliding sleeve. The fracturing sliding sleeve comprises an upper joint, an outer cylinder and a lower joint, which are sequentially connected from top to bottom, and a sliding sleeve, the side wall of the outer cylinder is provided with fracturing holes, and the sliding sleeve is locked in the outer cylinder and blocks the fracturing holes. The inner wall of the sliding sleeve is provided with axially distributed upper positioning grooves and lower positioning grooves. At least one of the fracturing sliding sleeves is a stage sliding sleeve, and the inner wall of the sliding sleeve of the stage sliding sleeve is provided with a locking groove. The outer wall of the opening key is provided with an upper positioning ring for matching the upper positioning grooves, a lower positioning ring for matching the lower positioning grooves and a locking ring for matching the locking groove, and the opening key can be elastically contracted inward. At least two of the fracturing sliding sleeves are cluster sliding sleeves, and the cluster sliding sleeves are sequentially connected from top to bottom, and the inner wall of the sliding sleeve of the lowermost cluster sliding sleeve in the same cluster is provided with a locking groove. The upper positioning ring and the lower positioning ring of the same opening key can match a plurality of cluster sliding sleeves in the same cluster. The upper positioning ring and the lower positioning ring of the opening key matching the cluster sliding sleeves are different from the upper positioning ring and the lower positioning ring of the opening key matching the stage sliding sleeve. The upper positioning ring, the locking ring and the lower positioning ring are sequentially distributed from top to bottom. The outer diameter of the upper positioning ring is greater than that of the locking ring, and the outer diameter of the lower positioning ring is greater than that of the locking ring.

2. The cement fracturing device of claim 1, wherein, The distance between the upper positioning grooves and the lower positioning grooves in the plurality of cluster sliding sleeves in the same cluster is equal. The distance between the upper positioning grooves and the lower positioning grooves in the cluster sliding sleeves is different from the distance between the upper positioning grooves and the lower positioning grooves in the stage sliding sleeve.

3. The cement fracturing device of claim 1, wherein, The cluster sliding sleeve comprises a baffle installed on the fracturing hole, the baffle is provided with a baffle hole, and the baffle is configured to be eroded by fracturing medium.

4. The cement fracturing device of claim 1, wherein, The lower inner wall of the locking groove is inclined downward in the radially outward direction, and the lower wall of the locking ring is inclined downward in the radially outward direction.

5. The cement fracturing device of claim 1, wherein, The lower wall of the upper positioning ring is inclined upward in the radially outward direction, and the lower wall of the lower positioning ring is inclined upward in the radially outward direction.

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