A disc valve type pressure stimulation tool

Abstract

The present invention relates to a disc valve type pressure excitation tool, which is used for casing in high friction wellbore, connected to the lowest end of the casing string, and comprises a static valve housing, a dynamic disc valve, a thrust bearing, a preloaded disc spring, a locking screw sleeve, a turbine shaft, a turbine rotor and a turbine stator, etc. The static valve housing and the turbine housing are threadedly connected to form a tool outer housing, the upper disc surface of the dynamic disc valve and the static valve housing are pre-pressed and fitted at the static valve disc, the dynamic disc valve is supported by a thrust bearing, the thrust bearing is supported by a preloaded disc spring and a locking screw sleeve arranged in sequence, the locking screw sleeve is threadedly fixedly connected to the inner wall of the static valve housing, the turbine rotor is fixed on the turbine shaft and can rotate with the shaft, and the turbine stator is fixed on the turbine housing. When the drilling fluid is circulated, when the static valve disc and the dynamic disc valve are rotating, the drilling fluid intermittently generates high pressure at the disc valve and forms intermittent thrust, so that the lower end casing string is in a vibrating state, which can effectively reduce the friction resistance of the casing string and improve the casing lowering ability.

Description

Technical Field

[0001] The invention relates to the technical field of casing tools for oil and gas field wellbore engineering, and in particular to a disc valve type pressure excitation tool. Background Art

[0002] For large displacement wells and horizontal wells with long horizontal sections, the borehole friction resistance is often high due to engineering problems. In order to solve the problem of difficulty in running casing, engineering and technical personnel have developed a variety of methods and measures, such as floating casing and rotating casing, but they are limited due to high costs or current process conditions. Studies have shown that when the casing is run by conventional methods, when the casing running force and the friction resistance are equal due to the high friction resistance of the wellbore, the casing string is in a compressed state near the zero point of the total resultant force distributed along the axis. If an effective vibration push force is applied to the end of the casing string, the friction resistance of the casing string below the zero point of the total resultant force will be significantly reduced, thereby eliminating this critical state that hinders the running of the casing and significantly improving the casing running capacity. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned problems and to provide a disc valve type pressure stimulation tool, which is fixedly connected to the end of the casing string. By circulating the drilling fluid, high pressure is intermittently generated in the tool to form intermittent thrust, so that the lower end casing string is in a vibrating state, which can effectively reduce the friction resistance of the casing string and improve the casing lowering ability.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A disc valve type pressure stimulation tool comprises a static valve housing, a dynamic disc valve, a thrust bearing, a preloaded disc spring, a locking screw sleeve, a spline shaft, a turbine shaft, a turbine housing, a turbine rotor and a turbine stator; wherein: the static valve housing is a cylindrical body, the lower end of the static valve housing and the turbine housing are sealed and connected to form a tool outer housing, a static valve disc is provided at the upper inner side of the static valve housing, and an offset flow hole is provided on the surface of the static valve disc; the dynamic disc valve is a cylindrical body, the upper end is a dynamic valve disc, the surface of the dynamic valve disc is provided with an offset flow hole identical to that of the static valve disc, the lower part of the dynamic valve disc is a disc valve handle of reduced diameter, the inner hole at the lower end of the disc valve handle is axially provided with an internal spline, and a plurality of guide holes are evenly distributed on the upper part of the internal spline; The bearing and the preloaded disc spring are installed on the upper part of the disc valve handle, and are fixedly connected to the static valve housing through a locking screw sleeve to pre-press and fit the moving valve disc of the moving disc valve with the static valve disc of the static valve housing; the upper end of the spline shaft is plug-fitted with the spline in the moving disc valve; the upper end of the turbine shaft is a clamping thread connected to the lower end of the spline shaft, and the lower part of the clamping thread is the rotor mounting shaft, the turbine rotor is fixed on the turbine shaft, and the corresponding turbine stator is fixed on the turbine housing, and the lower part of the rotor mounting shaft is a cylindrical hollow body, and a plurality of guide grooves are evenly distributed at the position of the cylindrical hollow body, and a bearing step is provided on the outer side of the turbine shaft at the lower part of the guide groove; the thrust bearing and the bearing step are tightly fitted to confine the turbine shaft to the lower end of the turbine housing.

[0006] The above scheme further comprises:

[0007] A flow bearing, an adjustment sleeve and a guide sleeve are arranged outside the turbine shaft below the turbine rotor from top to bottom.

[0008] The upper and lower end surfaces of the static valve disc of the static valve housing, the wall surface of the flow hole and the inner surface of the lower cylinder of the valve disc are provided with a wear-resistant strengthening coating, and the outer surface of the upper columnar body of the movable disc valve and the inner surface of the flow hole are wear-resistant outer strengthening coating.

[0009] The thrust bearing matched with the turbine shaft forms a closed structure through a bearing cover and a bearing cylinder, and the closed structure is fixedly connected to the turbine housing through pressure friction.

[0010] The turbine rotor and the turbine stator are composed of multiple groups of turbine sections.

[0011] The lower part of the static valve housing is connected to the turbine housing through a lower connecting thread, and a sleeve buckle thread is arranged at the inner upper end.

[0012] The locking screw sleeve is fixedly connected to the static valve housing through a supporting thread.

[0013] The upper end surface of the locking screw sleeve is a cross-section annular disc spring boss, the lower end surface is evenly distributed with a plurality of rectangular loading and unloading grooves, and the lower end of the inner hole is a trumpet-shaped guide port.

[0014] A keyway is arranged on the side of the rotor mounting shaft of the turbine shaft, and the turbine rotor is fixed on the turbine shaft by a key.

[0015] A plurality of tool grooves with rectangular cross sections are evenly distributed on the lower end surface of the turbine shaft.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. It is installed at the end of the casing string when in use, which is convenient for use with other tools or technical measures. The tool has a sturdy and simple structure, is safe and reliable; it can generate effective vibration force in the working state, significantly reduce the friction resistance of the casing string below the zero force point of the casing string, and improve the casing running ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a full cross-sectional structural diagram of a disc valve type pressure stimulation tool;

[0019] Figure 2 It is the structural diagram of the static valve housing;

[0020] Figure 3 It is the structural diagram of the moving disc valve;

[0021] Figure 4 It is the turbine shaft structure diagram;

[0022] Figure 5 This is a structural diagram of the locking screw sleeve.

[0023] In the figure: static valve housing 1, dynamic disc valve 2, thrust bearing 3, preloaded disc spring 4, locking nut 5, spline shaft 6, turbine shaft 7, flow bearing 8, adjustment sleeve 9, guide sleeve 10, bearing cover 11, bearing cylinder 12, turbine housing 13, key 14, turbine rotor 15, turbine stator 16, sleeve buckle thread 101, static valve disc 102, strengthening coating 103, supporting thread 104, lower connecting thread 105, dynamic valve disc 201, disc valve handle 202, guide hole 203, internal spline 204, bearing step 205, external strengthening coating 206, lower flow hole 207, disc spring boss 401, external supporting thread 402, loading and unloading groove 403, guide port 404, pressing thread 701, rotor mounting shaft 702, flow channel 703, tool groove 704, bearing step 705, guide groove 706, keyway 707. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] Example 1, reference Figure 1-5 As shown, a disc valve type pressure stimulation tool includes a static valve housing 1, a dynamic disc valve 2, a thrust bearing 3, a preloaded disc spring 4, a locking nut 5, a spline shaft 6, a turbine shaft 7, a turbine housing 13, a turbine rotor 15 and a turbine stator 16.

[0026] Among them: the static valve housing 1 is a cylindrical body, the lower end of the static valve housing 1 and the turbine housing 13 are sealed and connected to form the tool outer housing, the static valve housing 1 is provided with a static valve disc 102 on the upper inner side, and the static valve disc 102 is provided with an offset flow hole on the disc surface; the dynamic disc valve 2 is a cylindrical body, the upper end is a dynamic valve disc 201, the dynamic valve disc 201 is provided with an offset flow hole same as the static valve disc 102 on the disc surface, the lower part of the dynamic valve disc 201 is a reduced diameter disc valve handle 202, the inner hole at the lower end of the disc valve handle 202 is axially provided with an internal spline 204, and a plurality of guide holes 203 are evenly distributed on the upper part of the internal spline 204; the thrust bearing 3 and the preloaded disc spring 4 are sleeved on the upper part of the disc valve handle 202, and are fixedly connected to the static valve housing 1 through a locking screw sleeve 5. The moving valve disc 201 of the moving disc valve 2 is pre-pressed and fitted with the static valve disc 102 of the static valve housing 1; the upper end of the spline shaft 6 is plugged into the spline 204 inside the moving disc valve 2; the upper end of the turbine shaft 7 is a clamping thread 701 connected to the lower end of the spline shaft 6, and the lower part of the clamping thread 701 is a rotor mounting shaft 702, the turbine rotor 15 is fixed on the turbine shaft 7, and the corresponding turbine stator 16 is fixed on the turbine housing 13, the lower part of the rotor mounting shaft 702 is a cylindrical hollow body, and a plurality of guide grooves 706 are evenly distributed at the position of the cylindrical hollow body, and a bearing step 705 is provided on the outer side of the turbine shaft 7 at the lower part of the guide groove 706; the thrust bearing 3 and the bearing step 705 are tightly matched to confine the turbine shaft 7 to the lower end of the turbine housing 13.

[0027] Embodiment 2, a disc valve type pressure excitation tool includes a static valve housing 1, a dynamic disc valve 2, a thrust bearing 3, a preloaded disc spring 4, a locking nut 5, a spline shaft 6, a turbine shaft 7, a flow bearing 8, an adjustment sleeve 9, a guide sleeve 10, a bearing cover 11, a bearing cylinder 12, a turbine housing 13, a key 14, a turbine rotor 15 and a turbine stator 16, etc.

[0028] As attached Figure 1 As shown, the static valve housing 1 and the turbine housing 13 are threadedly connected to form a tool outer housing, the upper disk surface of the movable disc valve 2 contacts the disk surface of the static valve housing 1 at its static valve disk, the movable disc valve 2 is supported by a thrust bearing 3 in the middle part, the thrust bearing 3 is supported by a preloaded disc spring 4 and a locking screw sleeve 5 arranged in sequence, the locking screw sleeve 5 is threadedly fixedly connected to the inner wall of the static valve housing 1, the lower end of the movable disc valve 2 is connected to the turbine shaft 7 through a spline shaft 6, a plurality of turbine sections including a turbine rotor 15 and a turbine stator 16 are axially arranged on the turbine shaft 7, the turbine rotor 15 is fixed on the turbine shaft 7 and can rotate with the shaft, the turbine stator 16 is fixed on the turbine housing 13, the lower part of the turbine shaft 7 is axially fixed in a box-like structure composed of a bearing cover 11 and a bearing cylinder 12 through a thrust bearing 3, and this box-like structure is fixedly connected to the turbine housing 13 through pressure friction.

[0029] like Figure 2 As shown, the static valve housing 1 is a cylindrical body, the upper outer part is a cylinder of equal diameter, the lower part is a lower connecting thread 105 for connecting to the turbine housing 13, the upper inner end is a sleeve buckle thread 101, below is the static valve disc 102, the static valve disc 102 has an offset flow hole in the disc surface, the upper and lower end surfaces of the static valve disc 102, the wall of the flow hole and the inner surface of a certain size of the cylinder under the valve disc are wear-resistant strengthening coating 103, and below the strengthening coating is a supporting thread 104 for connecting the locking screw sleeve 5.

[0030] like Figure 3 As shown, the movable disc valve 2 is composed of a movable valve disc 201 and a disc valve handle 202. The upper outer side of the disc valve handle 202 is a columnar body, and the movable valve disc 201 is welded on the upper end. The disc surface of the movable valve disc 20 is perpendicular to the axis of the disc valve handle 202. The inner surface of the movable valve disc 201 is an offset lower flow hole 207. The outer surface of the upper column of the entire movable disc valve 2 and the inner side surface of the flow hole are welded with a wear-resistant outer strengthening coating 206. The step surface at the lower end of the columnar body is a bearing step 205. The inner hole at the lower end of the disc valve handle 202 is axially arranged with an internal spline 204, and a plurality of guide holes 203 are evenly distributed near the upper part of the internal spline 204.

[0031] like Figure 4As shown, the upper part of the turbine shaft 7 is a cylindrical solid body, and the lower part is a cylindrical hollow body. The hollow part is a flow channel 703. The outer side of the upper end is a clamping thread 701 for clamping the turbine rotor. Below it is a rotor mounting shaft 702. A keyway 707 is arranged on the side of the shaft. In the middle of the turbine shaft corresponding to the position of the cylindrical hollow body, a plurality of guide grooves 706 with oblong cross-sections are evenly distributed, which are used to guide the drilling fluid to flow through the cylindrical hollow body at the lower part of the turbine shaft. On the outer side of the lower column of the guide groove 706 is a bearing step 705 for installing a thrust bearing to limit the axial displacement of the turbine shaft. The lower end surface of the turbine shaft 7 is evenly distributed with a plurality of tool grooves 704 with rectangular cross-sections.

[0032] like Figure 5 As shown, the outer cylindrical surface of the locking screw sleeve 4 is an external supporting thread 402, and the upper end face is an annular disc spring boss 401 with a triangular cross-section, which can ensure that the deformation of the preloaded disc spring does not change when the axial force increases, and the lower end face is evenly distributed with multiple rectangular loading and unloading grooves 403, and the lower end of the inner hole is a trumpet-shaped guide port 404.

[0033] The disc valve type pressure stimulation tool mentioned in the present invention has the following use process:

[0034] According to the borehole trajectory logging data, the borehole friction resistance is judged, the connection tool is at the lowest end of the casing string, and when the casing string is lowered to a critical state, the pump is turned on to circulate the drilling fluid. When the drilling fluid flows through the inner cavity of the tool turbine section, the hydraulic force drives the turbine shaft 7 to rotate, thereby driving the movable disc valve 2 to rotate. The static disc valve 102 in the static valve housing 1 is integrated with the housing body. There is an offset flow hole in the static valve disc 102, and there is a same offset flow hole in the disc surface of the movable disc valve 2. When the movable disc valve 2 rotates around the axis of the static valve housing 1, the flow holes of the two disc valves overlap each other, so that the equivalent flow area changes between the maximum and minimum values. The drilling fluid intermittently generates high pressure at the disc valve and forms intermittent thrust. The drilling fluid finally enters the central guide hole of the turbine shaft 7 through the guide sleeve 10 and is discharged, so that the casing section below the neutral point of the casing string is in the axial vibration state of the casing string, thereby reducing the friction resistance of the entire casing string until the casing string is lowered to the designed position.

Claims

1. A disc valve type pressure stimulation tool, comprising a stationary valve housing (1), a movable disc valve (2), a thrust bearing (3), a preloaded disc spring (4), a locking nut (5), a spline shaft (6), a turbine shaft (7), a turbine housing (13), a turbine rotor (15) and a turbine stator (16); Its characteristics are: The static valve housing (1) is a cylindrical body. The lower end of the static valve housing (1) and the turbine housing (13) are sealed and connected to form a tool outer housing. A static valve disc (102) is provided at the upper inner side of the static valve housing (1). The static valve disc (102) is provided with an offset flow hole on its disc surface. The dynamic disc valve (2) is a cylindrical body. The upper end is a dynamic valve disc (201). The dynamic valve disc (201) is provided with an offset flow hole identical to that of the static valve disc (102). The lower part of the dynamic valve disc (201) is a reduced diameter disc valve handle (202). An internal spline (204) is axially arranged at the inner hole at the lower end of the disc valve handle (202). A plurality of flow guide holes (203) are evenly distributed at the upper part of the internal spline (204). A thrust bearing (3) and a preload disc spring (4) are sleeved on the upper part of the disc valve handle (202). The disc valve handle (202) is fixedly connected to the static valve housing (1) via a locking screw sleeve (5). 2) is pre-pressed and fitted with the static valve disc (102) of the static valve housing (1); the upper end of the spline shaft (6) is plugged into the spline (204) inside the dynamic disc valve (2); the upper end of the turbine shaft (7) is a clamping thread (701) connected to the lower end of the spline shaft (6), the lower part of the clamping thread (701) is a rotor mounting shaft (702), the turbine rotor (15) is fixed on the turbine shaft (7), the corresponding turbine stator (16) is fixed on the turbine housing (13), the lower part of the rotor mounting shaft (702) is a cylindrical hollow body, a plurality of guide grooves (706) are evenly distributed at the position of the cylindrical hollow body, and a bearing step (705) is provided on the outer side of the turbine shaft (7) below the guide groove (706); the thrust bearing (3) and the bearing step (705) are tightly fitted to confine the turbine shaft (7) to the lower end of the turbine housing (13).

2. The disc valve type pressure stimulation tool according to claim 1, Its characteristics are: A flow bearing (8), an adjustment sleeve (9) and a flow guide sleeve (10) are arranged outside the turbine shaft (7) below the turbine rotor (15) in this order from top to bottom.

3. The disc valve type pressure stimulation tool according to claim 1 or 2, Its characteristics are: The upper and lower end surfaces of the static valve disc of the static valve housing (1), the wall surface of the flow hole, and the inner surface of the lower cylinder of the valve disc are provided with a wear-resistant strengthening coating (103), and the outer surface of the upper columnar body of the movable disc valve (2) and the inner surface of the flow hole are provided with a wear-resistant outer strengthening coating (206).

4. The disc valve type pressure stimulation tool according to claim 3, Its characteristics are: A thrust bearing (3) matched with the turbine shaft (7) forms a closed structure through a bearing cover (11) and a bearing cylinder (12); the closed structure is fixedly connected to the turbine housing (13) through pressure friction.

5. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: The turbine rotor (15) and the turbine stator (16) are composed of multiple groups of turbine sections.

6. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: The lower part of the static valve housing (1) is connected to the turbine housing (13) via a lower connecting thread (105), and a sleeve buckle thread (101) is provided at the inner upper end.

7. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: The locking screw sleeve (5) is fixedly connected to the static valve housing (1) via a supporting thread (104).

8. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: The upper end surface of the locking screw sleeve (4) is a cross-section annular disc spring boss (401), the lower end surface is evenly distributed with a plurality of rectangular loading and unloading grooves (403), and the lower end of the inner hole is a trumpet-shaped guide port (404).

9. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: A keyway (707) is arranged on the side of the rotor mounting shaft (702) of the turbine shaft (7), and the turbine rotor (15) is fixed to the turbine shaft (7) via a key (14).

10. The disc valve type pressure stimulation tool according to claim 4, Its characteristics are: A plurality of tool grooves (704) with rectangular cross-sections are evenly distributed on the lower end surface of the turbine shaft (7).

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