Cement head

Abstract

The utility model belongs to the technical field of oil field well cementation operation, and particularly relates to a cement head. The cement head comprises a cement head body and a flow channel arranged in the cement head body, a rotary valve is rotatably installed in the flow channel, and a through hole which is through in the radial direction and allows a well cementation rubber plug to pass through is formed in the rotary valve. A groove penetrating through the rotary valve in the direction perpendicular to the axis direction of the through hole and the rotation axis direction of the rotary valve is formed in the orifice position of at least one end of the through hole, and the groove and the inner wall of the cement head body jointly define a channel allowing water slurry to pass through. The groove is formed in the opening of the through hole, allowing the well cementation rubber plug to pass through, of the rotary valve, the groove and the inner wall of the cement head body jointly define the channel allowing water slurry to pass through, the structure of the rotary valve is simplified, the manufacturing difficulty of the rotary valve is lowered, and the through-flow capacity of the rotary valve is improved; when plug throwing operation is carried out, clear water for pressing the well cementation rubber plug can wash the groove wall of the groove, attachments at the other end of the groove fall off under the action of gravity, and therefore the risk that cement paste is attached to the groove is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil field cementing operations, and particularly relates to a cement head. Background Art

[0002] A cement head is a device installed at the top of the casing during cementing, connecting the casing to the surface manifold. The cement head enables operations such as circulation, spacer fluid injection, cement slurry injection, plug release, and plug insertion. It serves as the central hub of the surface manifold wellhead for cementing operations.

[0003] For example, a Chinese invention patent application with application publication number CN117231157A and application publication date December 15, 2023 discloses a circulating manifold built-in rotary cement head, comprising a cement head body, a lifting short section is provided on the top of the cement head body, the bottom of the cement head body is sealed and connected to the lower outer cylinder, and the lower outer cylinder can rotate relative to the cement head body; a main flow channel and a secondary flow channel are respectively provided in the axial direction of the cement head body, a lower cylinder flow channel is provided in the axial direction of the lower outer cylinder, and a rotary valve is provided at the bottom of the main flow channel and the secondary flow channel, and the rotary valve can rotate to make the main flow channel rotate. The flow channel or the secondary flow channel is connected with the lower tube flow channel; the secondary flow channel is located on the side wall above the rotary valve and is connected with an injection union, and the top of the main flow channel and the secondary flow channel are connected; a first through hole, a second through hole and a third through hole are set on the rotary valve, wherein the second through hole for connecting the secondary flow channel and the first through hole is obliquely set on the side wall of the first through hole; the third through hole is through-set on the side wall of the first through hole; the first through hole is through-connected to connect the main flow channel and the lower tube flow channel for plugging operation, or the first through hole can connect the secondary flow channel, the second through hole and the third through hole, and the lower tube flow channel for non-plugging operation.

[0004] However, in the above scheme, a third through hole and an inclined second through hole need to be respectively provided on the rotary valve to be connected with the first through hole to form a grouting channel, which makes the structure of the rotary valve more complicated and increases the difficulty of manufacturing; after the cement slurry grouting is completed, since the cement slurry is a viscous fluid, it is easy to adhere to the inner walls of the second through hole and the third through hole. It is not easy to make the attached cement slurry flow out from the second through hole and the third through hole only by relying on the action of gravity. When the rotary valve rotates to the plugging operation state, the attached cement slurry residue cannot be cleaned in time. After long-term use, fluid residues will accumulate on the inner walls of the second through hole and the third through hole, and there is a risk of clogging the second through hole and the third through hole. Utility Model Content

[0005] The purpose of the utility model is to provide a cement head to solve the problem in the prior art that the rotating mechanism in the cement head body has a complex structure and is difficult to process, and the problem that residues are easily attached to the grouting channel, causing blockage after long-term use.

[0006] In order to achieve the above purpose, the cement head in the present invention adopts the following technical solutions:

[0007] A cement head comprises a cement head body and a flow channel arranged in the cement head body, a rotary valve is rotatably installed in the flow channel, the rotary valve is provided with a radial through hole for passage of a cementing plug, and a groove is provided at the orifice position of at least one end of the through hole, which passes through the rotary valve in a direction perpendicular to the axis of the through hole and the rotation axis of the rotary valve, and the groove is used to form a channel for passage of cement slurry together with the inner wall of the cement head body.

[0008] Furthermore, the groove wall of the groove is an arc surface.

[0009] Furthermore, a positioning tube for accommodating a cementing plug is provided above the rotary valve, and a first annulus communicating with the channel and allowing cement slurry to pass through is formed between the outer wall of the positioning tube and the inner wall of the cement head body.

[0010] Furthermore, the cement head body is provided with an injection port communicating with the inner cavity of the positioning tube above the positioning tube, and the positioning tube is provided with a first flow hole communicating with the first annulus and the inner cavity of the positioning tube.

[0011] Furthermore, a support tube for supporting the rotary valve is provided below the rotary valve, and a second annulus connected to the channel and for cement slurry to pass through is formed between the outer wall of the support tube and the inner wall of the cement head body, and a second flow hole is provided on the support tube to connect the second annulus and the inner cavity of the support tube.

[0012] Furthermore, a valve seat is provided in the flow channel, and the valve seat includes a first valve seat and a second valve seat arranged opposite to each other, and the axial ends of the rotary valve are rotatably mounted on the first valve seat and the second valve seat respectively through bearings.

[0013] Furthermore, the first valve seat and the second valve seat are respectively provided with mounting holes for installing bearings and annular grooves for sealing with the rotary valve. The groove walls of the annular grooves are provided with grease injection holes for connecting to the mounting holes to lubricate the bearings. The axial ends of the rotary valve are provided with convex rings that seal with the annular grooves. The convex rings are provided with a grease-passing structure, and the grease-passing structure is connected with the grease-passing hole during the rotation of the rotary valve.

[0014] Furthermore, the grease-passing structure is a grease-passing groove that completely cuts off the convex ring.

[0015] Furthermore, one axial end of the rotary valve is fixedly connected to a rotation control mechanism, and the rotary valve is also provided with a valve indicating structure for indicating the conduction state of the rotary valve, the valve indicating structure including a status indicating disk assembled on the rotation control mechanism, the status indicating disk being provided with an arc-shaped long hole, the valve indicating structure also including a limiting member provided on the cement head body and extending into the arc-shaped long hole, the circumferential ends of the arc-shaped long hole being respectively provided with a first mark for indicating that the rotary valve is in a state for allowing a plug to pass through and a second mark for allowing cement slurry to pass through, the first mark and the second mark cooperate with the limiting member to indicate the rotation state of the rotary valve.

[0016] Furthermore, a plug indicating structure is provided on the cement head body below the rotary valve, and the plug indicating structure includes a pin shaft and a trigger rod hinged to the cement head body through the pin shaft, and the trigger rod extends to the axis of the through hole at one end away from the hinge position; the plug indicating structure also includes an indicator rod coaxially fixed with the trigger rod, and the indicator rod is located outside the cement head body.

[0017] The beneficial effects of the present invention are as follows: the present invention is improved based on the existing technology, by arranging a groove that passes through the rotary valve in a direction perpendicular to the axis of the through hole and the rotation axis of the rotary valve at the orifice of at least one end of the through hole for the cementing plug to pass through the rotary valve, and the groove and the inner wall of the cement head body together form a channel for cement slurry to pass through, thereby simplifying the structure of the rotary valve, reducing the difficulty of manufacturing the rotary valve, and improving the flow capacity of the rotary valve; when the cement slurry grouting is completed, when the rotary valve rotates to the through hole conductive state for the plugging operation, the clean water used to pressurize the cementing plug can flush the groove wall of the groove, and the cement slurry and other attachments on the groove wall at the other end of the through hole can fall off under the action of gravity, thereby reducing the risk of cement slurry adhering to the groove, and further reducing the risk of flow channel blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a cement head in an embodiment of the present invention;

[0019] Figure 2 for Figure 1 sectional view of

[0020] Figure 3 This is a schematic diagram of the rotary valve structure in the cement head embodiment of the present utility model;

[0021] Figure 4 for Figure 3 sectional view of

[0022] Figure 5 This is a schematic diagram of the valve body structure of the rotary valve in the cement head embodiment of the present utility model;

[0023] Figure 6 for Figure 5 Schematic diagram from another perspective;

[0024] Figure 7 This is a schematic diagram of a working state of the rotary valve in the cement head embodiment of the present utility model;

[0025] Figure 8 This is a schematic diagram of another working state of the rotary valve in the cement head embodiment of the present utility model;

[0026] Figure 9 This is a schematic diagram of the structure of the rubber plug indicator in the cement head embodiment of the present utility model;

[0027] Figure 10 for Figure 7 A side sectional view of

[0028] Figure 11 This is a structural diagram of the second valve seat in the cement head embodiment of the present invention;

[0029] Figure 12 This is a structural diagram of the first valve seat in the cement head embodiment of the present utility model;

[0030] Figure 13 This is a structural schematic diagram of the status indicator plate in the cement head embodiment of the present utility model.

[0031] In the figure: 1, upper body; 2, lower body; 3, stopper pin wrench; 4, pitching mechanism; 6, rubber plug indicator; 7, injection union; 8, stopper pin mechanism; 9, rubber plug; 11, upper flow channel; 12, first annulus; 13, second sealing ring; 14, second annulus; 21, lower flow channel; 31, status indicator plate; 311, arc-shaped long hole; 61, trigger rod; 62, indicator housing; 63, indicator rod; 64, pin shaft; 65, screw plug; 66, third sealing ring; 81, positioning tube; 811, first Flow hole; 82, second valve seat; 821, mounting groove; 822, second mounting hole; 823, first grease injection hole; 824, sealing groove; 825, second grease injection hole; 826, screw hole; 827, positioning protrusion; 83, grease injection valve; 84, bearing; 85, support tube; 851, second flow hole; 852, trigger rod hole; 86, rotary valve; 861, through hole; 862, sealing protrusion; 8621, grease groove; 863, groove; 87, first valve seat; 871, first mounting hole. DETAILED DESCRIPTION

[0032] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0033] The cement head provided by the utility model provides a groove penetrating the rotary valve in a direction perpendicular to the axis of the through hole and the rotation axis of the rotary valve at the orifice of at least one end of the through hole for the cementing plug to pass through the rotary valve, and the groove and the inner wall of the cement head body together form a channel for cement slurry to pass through, thereby simplifying the structure of the rotary valve and reducing the difficulty of manufacturing the rotary valve; when in use, after the grouting is completed, the rotary valve rotates to the plugging operation state, and the clean water used to pressurize the cementing plug can flush the groove wall of the groove, and the cement slurry and other attachments on the groove wall at the other end can fall off under the action of gravity, thereby reducing the risk of cement slurry adhering to the groove, and further reducing the risk of flow channel blockage.

[0034] Embodiment of the cement head in the utility model:

[0035] like Figure 1 and Figure 2 As shown, the present embodiment provides a cement head, comprising a cement head body and a flow channel arranged in the cement head body, wherein the cement head body comprises an upper body 1 and a lower body 2 connected to the upper body 1, and after the upper body 1 and the lower body 2 are connected, a flow channel extending axially is formed therein, and the flow channel comprises an upper flow channel 11 located in the upper body 1 and a lower flow channel 21 located in the lower body 2, and a valve installation cavity connecting the upper flow channel 11 and the lower flow channel 21; a pin mechanism 8 for realizing the switching of the flow state of the flow channel is installed in the valve installation cavity.

[0036] Specifically, the upper portion of the upper body 1 is provided with an internal thread for connecting to a drill pipe, and the interior of the upper body 1 is provided with an upper inner hole extending along its axial direction, and the upper inner hole includes a first small-diameter section and a first expanded-diameter section connected to the first small-diameter section; the interior of the lower body 2 is provided with a lower inner hole extending through along its axial direction, and the lower inner hole includes a second small-diameter section and a second expanded-diameter section connected to the second small-diameter section; after the upper body 1 and the lower body 2 are connected, the inner cavity of the first small-diameter section forms the upper flow channel 11 of the upper body 1, the inner cavity of the second small-diameter section forms the lower flow channel 21 of the lower body 2, and the first expanded-diameter section and the second expanded-diameter section form a valve installation cavity connecting the upper flow channel 11 and the lower flow channel 21. The upper body 1 and the lower body 2 can be connected by threaded connection or other connection methods.

[0037] like Figures 2 to 6As shown, in this embodiment, the pin mechanism 8 includes a rotary valve 86, which is a ball valve; the rotation axis of the rotary valve 86 is perpendicular to the central axis of the lower body 2, and the rotary valve 86 is provided with a radial through hole 861 for the cementing plug to pass through, that is, the through hole 861 is used to axially connect the upper flow channel 11 and the lower flow channel 21. Through the through hole 861 of the rotary valve 86, the upper flow channel 11 and the lower flow channel 21 can be easily connected, thereby facilitating the passage of the cementing plug 9 during the plugging operation; at the same time, by rotating the rotary valve 86, the connection state of the through hole 861 with the upper flow channel 11 and the lower flow channel 21 can be easily switched. The aperture of the through hole 861 is larger than the outer diameter of the plug 9, so that the plug 9 can smoothly descend during the plugging operation. In its embodiment, the rotary valve 86 can also be a cylindrical valve body.

[0038] like Figure 5 and Figure 6 As shown, a groove 863 is provided at the opening of at least one end of the through hole 861, extending through the rotary valve 86 in a direction perpendicular to the axis of the through hole and the axis of rotation of the rotary valve 86. The groove 863 and the inner wall of the cement head body together form a channel for the cement slurry to pass through. Specifically, the groove wall of the groove 863 is an arc surface, that is, the groove 863 is an arc-shaped groove; the groove 863 and the inner wall of the valve mounting cavity together form a channel for the cement slurry to pass through. In this embodiment, the grooves 863 are respectively provided at the opening positions on both sides of the through hole 861 of the rotary valve 86. Of course, in other embodiments, the groove 863 can be provided only at the opening position on one side of the through hole 861; the groove wall of the groove 863 can be square, trapezoidal, or other suitable structural forms, which can be reasonably selected according to actual conditions. The rotary valve 86 of this embodiment does not require drilling holes on the rotary valve 86. Only a groove 863 is set on the rotary valve 86, and the groove 863 cooperates with the inner wall of the valve mounting cavity to form a channel for fluid to pass through, which effectively simplifies the structure of the rotary valve 86 and reduces the manufacturing difficulty of the rotary valve 86. At the same time, the formed channel can also better meet the flow requirements; the groove 863 is set perpendicular to the axis direction of the through hole and the rotation axis direction of the rotary valve, which facilitates the rotary valve 86 to rotate 90° to achieve the switching of the flow channel state, which is simple and labor-saving to operate. At the same time, compared with the existing technology, the groove 863 is set at the orifice position of the through hole 861, which makes the structure of the rotary valve 86 more compact, and thus the structure of the cement head body can be made compact.

[0039] like Figures 2 to 6As shown, as a further embodiment, the retaining pin mechanism 8 further includes a positioning tube 81 disposed above the rotary valve 86 and between the top wall of the valve mounting chamber. A first annulus 12 is formed between the outer wall of the positioning tube 81 and the inner wall of the valve mounting chamber. The inner cavity of the positioning tube 81 is used to accommodate the cementing plug 9 and form a passageway 861 connecting the upper flow channel 11 and the rotary valve 86 during the plugging operation. Specifically, the inner diameter of the positioning tube 81 is the same as that of the first small-aperture section. The opening of the first small-aperture section is provided with a stepped surface for positional engagement with the positioning tube 81. One end of the positioning tube 81 communicating with the upper flow channel 11 abuts the stepped surface, while the other end abuts the rotary valve 86. The end of the positioning tube 81 abutting the rotary valve 86 is a spherical structure. This facilitates assembly of the positioning tube 81 and also facilitates the formation of the first annulus 12 between the positioning tube 81 and the inner wall of the valve mounting chamber. The upper body 1 and the rotary valve 86 work together to confine the positioning tube 81 within the valve mounting chamber. In other embodiments, the positioning tube 81 may be connected to the first small-aperture section of the upper body 1 by threaded connection.

[0040] To facilitate communication between the first annulus 12 formed between the outer wall of the positioning tube 81 and the wall of the valve installation chamber and the inner cavity of the positioning tube 81, in this embodiment, a first flow hole 811 is provided near the top of the first small-diameter section of the positioning tube 81. In other embodiments, the communication between the first annulus 12 and the inner cavity of the positioning tube 81 can be a gap provided between the positioning tube 81 and the top wall of the valve installation chamber. Specifically, the lower end of the positioning tube is fixedly connected to the inner wall of the first expanded-diameter section of the lower body, and a certain gap is provided between the upper end of the positioning tube and the connection between the first small-diameter section and the first expanded-diameter section.

[0041] As a further embodiment, the retaining pin mechanism 8 also includes a support tube 85 disposed between the rotary valve 86 and the bottom wall of the valve mounting cavity. The inner cavity of the support tube 85 forms a passage connecting the through hole 861 of the rotary valve 86 and the lower flow channel 21. A second annulus 14 is formed between the outer wall of the support tube 85 and the inner wall of the lower joint 2, which is connected to the passage formed by the groove 863 and the inner wall of the cement head body and is used for the passage of cement slurry. Accordingly, the support tube is provided with four second flow holes 851 connecting the second annulus 14 with the inner cavity of the support tube 85. The inner diameter of the support tube 85 is the same as that of the lower flow channel 21. One end of the support tube 85 connected to the lower flow channel 21 abuts the orifice end face of the second small-diameter hole section, and the other end abuts the rotary valve 86. The end of the support tube 85 abutting the rotary valve 86 is a spherical structure. The lower body 2 and the rotary valve 86 work together to confine the support tube 85 within the valve mounting cavity, effectively supporting the rotary valve 86. In other embodiments, the opening of the second small-diameter section can be provided with a stepped surface that engages with the support tube 85; the support tube 85 can be connected to the second small-diameter section via a threaded connection. Of course, the support tube 85 can also be omitted.

[0042] In this embodiment, if Figure 4 As shown, and reference Figure 9 The support tube 85 is further provided with a trigger rod hole 852 for the trigger rod 61 of the plug indicator 6 to pass through.

[0043] refer to Figure 2 、 Figure 4 、 Figure 7 and Figure 8 As shown, during use, rotary valve 86 can rotate 90° to connect the first channel formed by through hole 861 and the second channel formed by groove 863 and the inner wall of the cement head body to the lower flow channel 21. This 90° rotation places rotary valve 86 in two states: one in which the upper flow channel 11, the first channel, and the lower flow channel 21 are connected during plugging operations; the other in which the fluid is connected through the upper flow channel 11, the first flow hole 811, the first annulus 12, the second channel, the second annulus 14, the second flow hole 851, and the lower flow channel 21 during grouting operations. The cement head adopts the structure of 90° rotary valve 86, which is simple to operate, safe, and labor-saving.

[0044] like Figures 2 to 6 、 Figure 11 and Figure 12 As shown, to facilitate assembly of the rotary valve 86 with the lower body 2, in this embodiment, a valve seat is provided within the flow passage of the cement head body, between the positioning tube 81 and the support tube 85. The valve seats include a first valve seat 87 and a second valve seat 82 disposed opposite each other. The rotary valve 86 rotatably engages with the first and second valve seats 87 and 82. Specifically, the first and second valve seats 87 and 82 each have a sector-shaped cross-section. The lower portion of the positioning tube 81 and the upper portion of the support tube 85 are respectively provided with positioning grooves that engage with the first and second valve seats 87 and 82. Connecting holes (not shown) are evenly distributed in the positioning grooves. Accordingly, positioning protrusions 827 that engage with the positioning grooves and screw holes 826 provided on the positioning protrusions 827 engage with the connecting holes. Fastening screws pass through the screw holes 826 and the connecting holes to connect the positioning tube 81 and the support tube 85 to the ends of the first and second valve seats 87 and 82, respectively.

[0045] The first valve seat 87 is provided with a first mounting hole 871 for rotationally engaging with the rotary valve 86, and the second valve seat 82 is provided with a second mounting hole 822 for rotationally engaging with the rotary valve 86. The axial ends of the rotary valve 86 are rotatably mounted within the first mounting hole 871 of the first valve seat 87 and the second mounting hole 822 of the second valve seat 82, respectively. In this embodiment, bearings 84 are respectively provided within the first mounting hole 871 and the second mounting hole 822. The axial ends of the rotary valve 86 are rotatably engaged with the first valve seat 87 and the second valve seat 82, respectively, via the bearings 84. The provision of bearings 84 reduces frictional resistance during rotation of the rotary valve 86, facilitating the state switching of the rotary valve 86. In other embodiments, the first valve seat 87 and the second valve seat 82 may be omitted, and the axial ends of the rotary valve 86 may be directly rotatably engaged with the sidewalls of the lower body 2. Specifically, mounting holes for axially engaging with the rotary valve 86 may be provided on the sidewalls of the lower body 2. The specific structure may be similar to the rotary valve 86 mounting structure described in CN117231157A.

[0046] It should be noted that in order to facilitate the connection between the stop pin wrench 3 and the rotary valve 86, a mounting groove 821 for the stop pin wrench 3 to pass through is provided on the second valve seat 82; the second mounting hole 822 is a through hole for allowing one axial end of the rotary valve 86 to pass through. Except for the second mounting hole 822 and the mounting groove 821, the other structures of the second valve seat 82 are consistent with the structure of the first valve seat 87.

[0047] like Figures 4 to 6 、 Figure 11 and Figure 12 As shown, to improve the sealing performance of the rotary valve 86 during rotational engagement with the first and second valve seats 87 and 82, in this embodiment, an annular sealing groove 824 is provided on each of the first and second valve seats 87 and 82. Correspondingly, a sealing protrusion 862 is provided on each of the axial end faces of the rotary valve 86 to mate with the sealing groove 824. Specifically, the sealing protrusion 862 comprises four evenly spaced annular protrusions, each located on the same circumference. Grease grooves 8621 are located between adjacent annular protrusions, completely separating the protrusions. These grease grooves 8621 form a grease-passing structure. After the rotary valve 86 is rotationally assembled with the first and second valve seats 87 and 82, the sealing protrusion 862 is inserted into the sealing groove 824, forming a surface seal between the sealing protrusion 862 and the sealing groove 824, thereby effectively ensuring the rotational sealing performance between the rotary valve 86 and the first and second valve seats 87 and 82. In other embodiments, the sealing protrusion 862 may be a continuous annular protrusion with a conductive hole formed therein, the conductive hole forming a grease-passing structure; or the annular protrusion may be provided in two sections. It should be understood that the number of annular protrusions provided and the structural form of the grease-passing structure may be reasonably selected as needed.

[0048] In order to facilitate the lubrication of the bearing 84, in this embodiment, a grease injection valve 83 is provided on the first valve seat 87 and the second valve seat 82, and a first grease injection hole 823 for communicating with the grease injection valve 83 and a second grease injection hole 825 for injecting grease into the bearing are respectively provided on the groove walls of the sealing groove 824 of the first valve seat 87 and the second valve seat 82, wherein the first grease injection hole 823 and the second grease injection hole 825 are arranged corresponding to each other, and the two first grease injection holes 823 and the two second grease injection holes 825 are respectively evenly spaced along the circumference of the sealing groove 824. After the rotary valve 86 is rotated and assembled with the first valve seat 87 and the second valve seat 82, the grease groove 8621 communicates with the first grease injection hole 823 and the second grease injection hole 825 as the rotary valve 86 rotates. Specifically, when the rotary valve 86 rotates 90 degrees relative to the first valve seat 87 and the second valve seat 82, the grease groove 8621 of the sealing protrusion 862 communicates with the first grease injection hole 823 and the second grease injection hole 825. At this time, the first grease injection hole 823, the grease groove 8621, and the second grease injection hole 825 form a lubrication channel for lubricating the bearing 84. The lubrication channel formed by the first grease injection hole 823, the grease groove 8621, and the second grease injection hole 825 facilitates lubrication of the bearing 84.

[0049] like Figure 2 As shown, in this embodiment, a rotation control structure is provided at one axial end of the rotary valve 86. Specifically, the rotation control structure is a stop pin wrench 3. The portion of the axial end of the rotary valve 86 that engages with the stop pin wrench 3 is engaged by a square or hexagonal anti-rotation structure. The external rotational torque applied by the stop pin wrench 3 can be transmitted to the rotary valve 86 via the square or hexagonal structure. Of course, in other embodiments, the stop pin wrench can be connected to the axial end of the rotary valve via a threaded connection. Accordingly, the axial end of the rotary valve has internal or external threads that are compatible with the stop pin wrench.

[0050] In order to ensure the sealing performance of the rotational fit between the stop pin wrench 3 and the lower joint body, a first sealing ring (not shown in the figure) is provided on the stop pin wrench 3.

[0051] like Figure 2 and Figure 4 As shown, in order to accurately determine the open or closed state of the rotary valve 86, in this embodiment, the rotary valve 86 is further provided with a valve indicating structure for indicating the conduction state of the rotary valve 86. Specifically, referring to Figure 13As shown, the valve indication structure includes a status indication disk 31 and a limit pin; the status indication disk 31 is assembled on the end of the stop pin wrench 3 away from the rotary valve 86, and a circular arc-shaped long hole 311 is provided on the status indication disk 31, and the two ends of the arc-shaped long hole 311 form a first mark for indicating that the rotary valve 86 is in a state for allowing the plug to pass through or a second mark for allowing the cement slurry to pass through, wherein the first mark and the second mark are spaced 90° apart, and the first mark and the second mark cooperate with the limit pin to indicate the rotation state of the rotary valve 86; the limit pin is fixed on the outer wall of the lower body 2 and is located on the rotation stroke of the arc-shaped long hole 311; the circumferential ends of the arc-shaped long hole 311 are respectively used to cooperate with the limit pin stopper. By the limiting cooperation between the limit pin and the status indicator disk 31, the rotary valve 86 is indicated to be in the first indicating position for the passage of the rubber plug 9 or the second indicating position for the passage of cement slurry. At the same time, the limit pin cooperates with the stopper of the arc-shaped long hole to limit the rotation angle of the stop pin wrench 3, thereby controlling the rotation angle of the rotary valve 86.

[0052] like Figure 2 、 Figure 5 、 Figure 9 and Figure 10 As shown, in order to accurately determine whether the plug 9 has fallen normally, in this embodiment, a plug indicator 6 is fixedly installed on the lower body 2 below the rotary valve 86. Specifically, the plug indicator 6 includes an indicator housing 62 fixedly connected to the lower body 2, a trigger rod 61, and a pin 64. One end of the trigger rod 61 is hinged to the indicator housing 62 via the pin 64, and the other end away from the hinge position extends into the flow channel. Preferably, the end of the trigger rod 61 away from the hinge position extends at least to the axis of the through hole 861 of the rotary valve 86. In this embodiment, the end of the trigger rod 61 away from the hinge position passes over the axis of the through hole 861 of the rotary valve 86 to ensure sufficient contact area between the trigger rod 61 and the plug 9. Of course, it should be noted that the length of the trigger rod 61 should ensure that it can be rotated in and out of the trigger rod hole 852 of the support tube 85 and can be pushed against the plug 9 during the plugging operation. The trigger lever 61 has a hexagonal hole at one end that mates with the pin 64. Correspondingly, the middle portion of the pin 64 has an outer hexagonal structure that mates with the hexagonal hole in the trigger lever 61, thereby enabling the pin 64 and the trigger lever 61 to rotate synchronously. Of course, the structure for the trigger lever 61 to mate with the rotating shaft can be triangular, square, or other relatively anti-rotation structures, and this is not limited in this embodiment. During use, the trigger lever 61, under the action of its own gravity and the action of the plug 9, flips into the indicator housing 62, allowing the trigger lever 61 to fully retract, releasing the plug 9 and allowing it to be released. This prevents the downward movement of the plug 9 from being affected by the trigger lever 61 not being fully opened, allowing the plug 9 to be released smoothly.

[0053] In this embodiment, an indicator rod 63, which can indicate whether the trigger rod 61 is open or closed, is fixedly mounted on one end of the pin 64. Specifically, the indicator rod 63 is located outside the cement head body and is fixed to the pin 64 via a thin nut. The indicator rod 63 is arranged at a 90-degree angle to the trigger rod 61. During use, when the trigger rod 61 is flipped open, the pin 64 rotates with the trigger rod 61 and drives the indicator rod 63 to rotate, indicating that the trigger rod 61 is open. When the trigger rod 61 is reset, the indicator rod 63 is pulled to drive the pin 64 to rotate, causing the trigger rod 61 to flip and reset. The changes in the position of the indicator rod 63 allow cementing operators to promptly understand the open state of the trigger rod 61 and accurately determine the drop of the rubber plug 9.

[0054] In order to ensure the sealing performance of the rotational fit between the pin shaft 64 and the indicator housing 62 , in this embodiment, a plurality of third sealing rings 66 are respectively provided between the pin shaft 64 and the indicator housing 62 at the rotational fit between the two.

[0055] To facilitate the removal of cement and other sediments within the indicator housing 62, in this embodiment, the indicator housing 62 is further provided with a sand-cleaning hole, which is equipped with a screw plug 65. During use, sediments deposited within the indicator housing 62 can be cleaned through the sand-cleaning hole, thereby preventing the trigger lever 61 from getting stuck during rotation and affecting the determination of the drop of the rubber plug 9, or preventing the trigger lever 61 from being unable to rotate into position and affecting the downward movement of the rubber plug 9.

[0056] like Figure 2 As shown, in order to improve the sealing performance after the upper body 1 and the lower body 2 are connected, in this embodiment, a sealing structure is provided between the lower body 2 and the upper body 1. Specifically, a sealing groove is provided at one end of the lower body 2 that cooperates with the upper body 1, and a second sealing ring 13 is arranged in the sealing groove.

[0057] like Figure 1 and Figure 2 As shown, in this embodiment, the upper body 1 is provided with an injection union 7 connected to the upper flow channel 11 above the rotary valve 86. Specifically, the upper body 1 is provided with an injection port connected to the flow channel above the positioning tube 81, and the injection union 7 is connected to the injection port on the upper body 1 by welding. In other embodiments, the injection union 7 can be fixedly connected to the upper body 1 by threads or bolts. The injection union 7 is connected to the external cementing pipeline to achieve the injection of various fluids. Of course, as another embodiment, the injection union 7 can be connected to the first annulus 12. During the plugging operation, the injected fluid ascends through the first annulus 12 and enters the first channel through the flow hole provided on the positioning tube 81.

[0058] In this embodiment, a ball throwing mechanism 4 is provided on the lower body 2 below the stop pin mechanism 8. Specifically, the ball throwing mechanism 4 is provided on the second small aperture section of the lower body 2. When a ball throwing operation is required, the ball is thrown through the ball throwing mechanism 4.

[0059] like Figures 1 to 13 As shown, based on the structural description of the cement head above, the assembly process of the cement head provided by the present invention is briefly described as follows:

[0060] 1) Assemble the rotary valve 86. Install the bearings 84 at both axial ends of the rotary valve 86 of the rotary valve 8. Place the assembled rotary valve 86 on the support tube 85. Place the positioning tube 81 above the rotary valve 86. Then, connect the first valve seat 87 and the second valve seat 82 to the support tube 85 and the positioning tube 81, respectively.

[0061] 2) Assemble external components. Weld the ball-casting mechanism 4 and indicator housing 62 to the lower body 2, and weld the injection union 7 to the upper body 1.

[0062] 3) Assemble the stop pin wrench 3 and the rotary valve 86. Assemble the first sealing ring on the stop pin wrench 3, and then assemble the stop pin wrench 3 on the lower body 2; install the rotary valve 86 assembled in step (1) into the lower body 2, and make one axial end of the rotary valve 86 fit with the stop pin wrench 3; assemble the status indicator disk 31, and adjust the position of the status indicator disk 31 so that it matches the status of the rotary valve 86, and assemble the limit pin.

[0063] 4) Assemble the rubber plug indicator 6. Assemble the trigger rod 61 to the indicator housing 62 via the pin 64, and assemble the indicator rod 63 to the pin 64. Adjust the indicator rod 63 so that the trigger rod 61 is in a horizontal state.

[0064] 5) Assemble the upper body 1 and the lower body 2. Place the rubber plug 9 into the positioning tube 81 of the stopper mechanism 8, insert the lower body 2 assembled in step (3) into the upper body 1, and connect the lower body 6 and the upper body 1.

[0065] After assembly, the trigger rod 61 of the cement head provided by the present invention is in a closed state, the first channel for plugging operation is in a closed state, and the second channel for grouting operation is in an open state.

[0066] refer to Figures 2 to 4 、 Figure 7 and Figure 8 As shown, based on the structural description of the cement head above, the use process of the cement head provided by the utility model is briefly described as follows:

[0067] During grouting operations, the through hole 861 of the rotary valve 86 is not connected to the upper flow channel 11 and the lower flow channel 21, and the rubber plug 9 maintains the position after assembly; the upper flow channel 11 is connected to the lower flow channel 21 through the first flow hole 811, the first annulus 12, the second channel and the second annulus 14, and the second flow hole 851; when the isolation fluid and cement slurry are respectively injected through the injection union 7, the fluid enters the well through the upper flow channel 11, the first flow hole 811, the first annulus 12, the second channel, the second annulus 14, the second flow hole 851 and the lower flow channel 21.

[0068] During the plugging operation, based on the state of the rotary valve 86 during the aforementioned grouting operation, the pin wrench 3 is rotated to rotate the rotary valve 86 90°, so that the first channel of the rotary valve 86 is connected with the upper flow channel 11 and the lower flow channel 21, and the second channel is closed; when the slurry displacement fluid (generally clean water) enters through the injection union 7, the slurry displacement fluid enters the inner cavity of the positioning tube 81 through the upper flow channel 11, drives the rubber plug 9 downward, and then descends through the through hole 861, the inner cavity of the support tube 85 and the lower flow channel 21 in turn to enter the well, thereby achieving plugging.

[0069] As another embodiment, instead of providing a separate status indicator plate, the first mark and the second mark may be provided on the side wall of the cement head body respectively.

[0070] As another embodiment, the first grease injection hole and the second grease injection hole are not arranged correspondingly, and the grease passing structure on the convex ring is aligned with the first grease injection hole and the second grease injection hole in sequence, so that the grease is automatically distributed to the position that needs lubrication when the rotary valve rotates.

[0071] As another embodiment, positioning steps for positioning the first valve seat and the second valve seat are respectively provided in the upper inner hole of the upper body and the lower inner hole of the lower body. During assembly, the axial ends of the first valve seat and the second valve seat are respectively mounted on the positioning steps.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the description and drawings of the present invention shall also be included in the scope of protection of the present invention.

Claims

1. A cement head, comprising a cement head body and a flow channel disposed within the cement head body, wherein a rotary valve is rotatably mounted within the flow channel, and wherein the rotary valve is provided with a radially penetrating through hole for passage of a cementing plug, wherein: A groove is provided at the opening of at least one end of the through hole and passes through the rotary valve in a direction perpendicular to the axis of the through hole and the rotation axis of the rotary valve. The groove is used to form a channel for cement slurry to pass through together with the inner wall of the cement head body.

2. The cement head according to claim 1, characterized in that: The groove wall of the groove is an arc surface.

3. The cement head according to claim 1, characterized in that: A positioning tube for accommodating a cementing plug is provided above the rotary valve, and a first annulus communicating with the channel and allowing cement slurry to pass through is formed between the outer wall of the positioning tube and the inner wall of the cement head body.

4. The cement head according to claim 3, characterized in that: The cement head body is provided with an injection port communicated with the inner cavity of the positioning pipe above the positioning pipe, and the positioning pipe is provided with a first flow hole to communicate the first annulus and the inner cavity of the positioning pipe.

5. The cement head according to any one of claims 1 to 4, characterized in that: A support tube for supporting the rotary valve is provided below the rotary valve, and a second annulus connected to the channel and for cement slurry to pass through is formed between the outer wall of the support tube and the inner wall of the cement head body. A second flow hole is provided on the support tube to connect the second annulus and the inner cavity of the support tube.

6. The cement head according to any one of claims 1 to 4, characterized in that: A valve seat is provided in the flow channel, and the valve seat includes a first valve seat and a second valve seat which are arranged opposite to each other. The axial ends of the rotary valve are rotatably mounted on the first valve seat and the second valve seat respectively through bearings.

7. The cement head according to claim 6, characterized in that: The first valve seat and the second valve seat are respectively provided with mounting holes for installing bearings and annular grooves for sealing with the rotary valve. The groove walls of the annular grooves are provided with grease injection holes for connecting with the mounting holes to lubricate the bearings. The axial ends of the rotary valve are provided with convex rings that seal with the annular grooves. The convex rings are provided with a grease-passing structure, and the grease-passing structure is connected with the grease injection holes during the rotation of the rotary valve.

8. The cement head according to claim 7, characterized in that: The grease-passing structure is a grease-passing groove that completely cuts off the convex ring.

9. The cement head according to any one of claims 1 to 4, characterized in that: One axial end of the rotary valve is fixedly connected to a rotation control mechanism, and the rotary valve is further provided with a valve indicating structure for indicating the conduction state of the rotary valve, the valve indicating structure comprising a status indicating disk assembled on the rotation control mechanism, the status indicating disk being provided with an arc-shaped long hole, the valve indicating structure further comprising a limiting member provided on the cement head body and extending into the arc-shaped long hole, the circumferential ends of the arc-shaped long hole being respectively provided with a first mark for indicating that the rotary valve is in a state for allowing a plug to pass through and a second mark for allowing cement slurry to pass through, the first mark and the second mark cooperating with the limiting member to indicate the rotation state of the rotary valve.

10. The cement head according to any one of claims 1 to 4, characterized in that: A plug indicating structure is provided on the cement head body below the rotary valve. The plug indicating structure includes a pin shaft and a trigger rod hinged to the cement head body through the pin shaft, and one end of the trigger rod away from the hinge position extends to the axis of the through hole; the plug indicating structure also includes an indicator rod coaxially fixed with the trigger rod, and the indicator rod is located outside the cement head body.

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