CN110905429B - Automatic pressure relief balanced type setting tool and setting method thereof - Google Patents
Automatic pressure relief balanced type setting tool and setting method thereof Download PDFInfo
- Publication number
- CN110905429B CN110905429B CN201911127363.0A CN201911127363A CN110905429B CN 110905429 B CN110905429 B CN 110905429B CN 201911127363 A CN201911127363 A CN 201911127363A CN 110905429 B CN110905429 B CN 110905429B
- Authority
- CN
- China
- Prior art keywords
- shell
- step surface
- core rod
- pressure relief
- wall
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 12
- 238000007789 sealing Methods 0.000 claims abstract description 40
- 239000003721 gunpowder Substances 0.000 claims abstract description 12
- 239000002360 explosive Substances 0.000 claims description 15
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 238000010008 shearing Methods 0.000 claims description 5
- 239000012530 fluid Substances 0.000 description 6
- 239000003380 propellant Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 230000032258 transport Effects 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B23/00—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
- E21B23/06—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells for setting packers
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/14—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Portable Nailing Machines And Staplers (AREA)
Abstract
The invention discloses an automatic pressure relief balanced type setting tool and a setting method thereof, wherein the tool comprises a core bar, a sliding sleeve and a shell, the core bar is provided with an inner hole for mounting a gunpowder column, the core bar is radially provided with a vent hole in a through manner, the outer wall of the core bar is provided with an outer step surface for limiting the movement position of the shell, the outer wall of the lower end of the core bar is provided with a pressure relief groove, the inner wall of the lower end of the shell is provided with an inner step surface, and the inner step surface of the shell is positioned below the outer step surface; in an initial state, the core bar is fixedly connected with the sliding sleeve, the upper end of the shell is fixedly connected with the sliding sleeve, the inner step surface of the shell is in sealing fit with the outer wall of the core bar, and the vent hole is communicated with an annular space between the inner step surface and the outer step surface; when the bridge plug is in a setting state, the sliding sleeve moves downwards to the position of the outer step surface of the core rod for limiting, the inner step surface of the shell is positioned in the pressure relief groove, and a pressure relief channel is formed by a gap between the inner step surface and the pressure relief groove. The invention can be used for high-pressure wells and has the functions of automatic pressure relief and self-balancing.
Description
Technical Field
The invention relates to the technical field of oil and gas field development, in particular to a gas pressure push type bridge plug setting tool with the functions of automatic pressure relief and balancing hydrostatic column pressure in a well and a setting method thereof, which are used for bridge plug setting operation.
Background
The bridge plug is widely applied to the aspect of oil and gas well seal, and is a main seal process for plugging a tested layer of a test oil well and performing upward return test oil. The squeeze sealing process of the bridge plug needs to be accomplished by means of a setting tool that transports the bridge plug into the well. The bridge plug setting tool in the prior art is more, for example, a bridge plug setting tool disclosed in chinese patent publication No. 208918507U, published as 2019-05-31, which comprises a pressure relief recoil chamber and a propellant chamber, wherein the pressure relief recoil chamber is hermetically connected with the propellant chamber; a sealing needle for communicating the cable and the pressure relief recoil chamber is arranged at the top of the pressure relief recoil chamber; the middle part of the pressure relief recoil chamber is provided with an upward inclined pressure relief pore passage; a piston body is arranged at the bottom of the pressure relief backflushing chamber; the opening end of the piston body is upward and is fixed on the inner side wall of the pressure relief recoil chamber through the fixing piece, the piston body and the inner side wall of the pressure relief recoil chamber are matched to seal a pressure relief pore passage under a normal state, and when the ignition device works, the fixing piece is cut off by means of pressure generated by the explosive chamber, so that the piston body moves upwards to expose the pressure relief pore passage and perform pressure relief recoil.
However, the existing common bridge plug setting tool is not reasonable enough in structural design, the tool is always subjected to the reverse acting force generated by the liquid pressure in the well in the process of extruding the bridge plug, and the pressure generated by the combustion of gunpowder can extrude the bridge plug to move after overcoming the reverse acting force of the pressure in the well. Because the well condition parameters such as setting depth, well pressure and the like of each well are different, the reaction force of well fluid is also different, so that the consistency of actual output of the setting force is influenced, and particularly when the reaction force is overlarge, half setting of a bridge plug can be caused. The gas pressure is remained in the tool, and the tool needs manual pressure relief and is dangerous. And the tool is heavy, needs many people to work in coordination, and the maintenance cycle is long.
Disclosure of Invention
The invention aims to overcome the problems in the prior art and provides an automatic pressure relief balanced type setting tool and a setting method thereof. The invention can be used for high-pressure wells and has the functions of automatic pressure relief and self-balancing.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the utility model provides an automatic pressure release balanced type setting instrument which characterized in that: the device comprises a core bar, a sliding sleeve and a shell, wherein the core bar is provided with an inner hole for mounting a gunpowder column, the core bar is radially provided with a vent hole in a through manner, the outer wall of the core bar is provided with an outer step surface for limiting the movement position of the shell, the outer step surface of the core bar is in sealing fit with the inner wall of the shell, the outer wall of the lower end of the core bar is provided with a pressure relief groove, the inner wall of the lower end of the shell is provided with an inner step surface, and the inner step surface of the shell; in an initial state, the core bar is fixedly connected with the sliding sleeve and is in sealing fit with the inner wall of the sliding sleeve, the upper end of the shell is fixedly connected with the sliding sleeve, the inner wall of the shell is in sealing fit with the outer wall of the sliding sleeve, the inner step surface of the shell is in sealing fit with the outer wall of the core bar, and the vent hole is communicated with an annulus between the inner step surface and the outer step surface; when the bridge plug is in a setting state, the sliding sleeve moves downwards to the position of the outer step surface of the core rod for limiting, the inner step surface of the shell is positioned in the pressure relief groove, and a pressure relief channel is formed by a gap between the inner step surface and the pressure relief groove.
The number of the vent holes is 4, and the vent holes are arranged on the same circumference of the core rod.
The sliding sleeve is fixedly connected with the core rod through a shear screw.
The size of the sealing surface between the sliding sleeve and the core rod is consistent with that of the sealing surface between the shell and the core rod.
The sliding sleeve is in sealing fit with the core rod through the O-shaped ring on the inner wall, and is in sealing fit with the shell through the O-shaped ring on the outer wall.
Two O-shaped rings are arranged on the outer step surface of the core rod, and the outer step surface of the core rod is in sealing fit with the inner wall of the shell through the O-shaped rings.
Two O-shaped rings are arranged on the inner step surface of the shell, and the inner step surface of the shell is in sealing fit with the outer wall of the core rod through the O-shaped rings.
The sliding sleeve is fixedly connected with the upper end of the shell through threads.
A setting method of an automatic pressure relief balanced type setting tool is characterized by comprising the following steps: the ground is electrified to ignite the explosive column, gas generated by combustion of the explosive column is transmitted to the step surface in the shell through the vent hole of the core rod, the pressure of the explosive is continuously increased, the shearing screw is cut off, the shell and the core rod generate relative motion, the bridge plug is extruded to realize setting, and when the inner step surface of the shell moves to the pressure relief groove of the core rod, the gas pressure in the core rod is communicated with the outside, so that automatic pressure relief is realized.
The invention has the advantages that:
1. the invention is used for the oil gas well to sit and seal the bridge plug, because the sliding sleeve and body are influenced by well fluid the sealing surface diameter is the same, the liquid pressure in the well acts on the sliding sleeve and body and is equal to the force that is upward and downward on the whole, the sliding sleeve and body are no longer influenced by well fluid pressure when moving, the gunpowder pressure all acts on the bridge plug, sit and seal stably and reliably, after the body moves to certain distance, realize and sit and seal the bridge plug, release the gas pressure in the core bar automatically in the oil gas well, prevent the ground from releasing pressure artificially and hurting people, and does not pollute the ground environment. The product is light and convenient and can be operated by one person.
2. The size of the sealing surface between the sliding sleeve and the core rod is consistent with that of the sealing surface between the shell and the core rod, so that the force of the liquid pressure in the well acting on the shell can be mutually counteracted, the shell is not influenced by the liquid pressure in the well when moving, the gunpowder gas pressure completely acts on the shell, and the stable and reliable operation is ensured.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic diagram of the present invention after operation;
FIG. 3 is a schematic view of a setting tool work string;
labeled as: 1. the explosive-proof device comprises a core bar, 2, a sliding sleeve, 3, a shell, 4, vent holes, 5, a pressure relief groove, 6, a bridge plug, 7, a shear screw, 8, an O-shaped ring, 9, an explosive column, 10 and an adapter.
Detailed Description
Example 1
An automatic pressure relief balanced type setting tool comprises a core bar 1, a sliding sleeve 2 and a shell 3, wherein the core bar 1 is provided with an inner hole for mounting a gunpowder column, the core bar 1 is radially provided with a vent hole 4 in a through manner, the outer wall of the core bar 1 is provided with an outer step surface for limiting the movement position of the shell 3, the outer step surface of the core bar 1 is in sealing fit with the inner wall of the shell 3, the outer wall of the lower end of the core bar 1 is provided with a pressure relief groove 5, the inner wall of the lower end of the shell 3 is provided with an inner step surface, and the inner step surface of the shell 3 is positioned below; in an initial state, the core bar 1 is fixedly connected with the sliding sleeve 2 and is in sealing fit with the inner wall of the sliding sleeve 2, the upper end of the shell 3 is fixedly connected with the sliding sleeve 2, the inner wall of the shell 3 is in sealing fit with the outer wall of the sliding sleeve 2, the inner step surface of the shell 3 is in sealing fit with the outer wall of the core bar 1, and the vent hole 4 is communicated with an annular space between the inner step surface and the outer step surface; when the bridge plug 6 is in a setting state, the sliding sleeve 2 moves downwards to the position of the outer step surface of the core rod 1 for limiting, the inner step surface of the shell 3 is positioned in the pressure relief groove 5, and a pressure relief channel is formed by a gap between the inner step surface and the pressure relief groove 5.
The number of the vent holes 4 is 4, and the vent holes are arranged on the same circumference of the core rod 1.
The sliding sleeve 2 is fixedly connected with the core bar 1 through a shear screw 7.
The size of the sealing surface between the sliding sleeve 2 and the core bar 1 is consistent with that of the sealing surface between the shell 3 and the core bar 1.
Two O-shaped rings 8 are arranged on the inner wall and the outer wall of the sliding sleeve 2, the sliding sleeve 2 is in sealing fit with the core rod 1 through the O-shaped rings 8 on the inner wall, and is in sealing fit with the shell 3 through the O-shaped rings 8 on the outer wall.
Two O-shaped rings 8 are arranged on the outer step surface of the core rod 1, and the outer step surface of the core rod 1 is in sealing fit with the inner wall of the shell 3 through the O-shaped rings 8.
Two O-shaped rings 8 are arranged on the inner step surface of the shell 3, and the inner step surface of the shell 3 is in sealing fit with the outer wall of the core rod 1 through the O-shaped rings 8.
The sliding sleeve 2 is fixedly connected with the upper end of the shell 3 through threads.
A setting method of an automatic pressure relief balanced setting tool comprises the following steps: the ground is electrified to ignite the explosive column, gas generated by combustion of the explosive column is transmitted to the step surface in the shell through the vent hole of the core rod, the pressure of the explosive is continuously increased, the shearing screw is cut off, the shell and the core rod generate relative motion, the bridge plug is extruded to realize setting, and when the inner step surface of the shell moves to the pressure relief groove of the core rod, the gas pressure in the core rod is communicated with the outside, so that automatic pressure relief is realized.
Example 2
The setting tool and the working principle of the invention are described in detail with reference to the accompanying drawings and the specific examples.
The setting tool is used for setting the bridge plug in oil and gas well operation.
As shown in fig. 1 and 2, the setting tool comprises a shear screw 7, a sliding sleeve 2, a shell 3, a core bar 1 and an O-ring 8.
The core rod 1 is provided with an inner hole for installing a gunpowder column, and is communicated with 4 vent holes 4 on the excircle, and the shell 3 and the core rod 1 can be pushed to move mutually by gas pressure generated by the gunpowder column.
The core rod 1 is provided with a pressure relief groove 5, and when the shell 3 moves to a certain distance, the gas pressure in the core rod 1 can be automatically released after the bridge plug 6 is sealed.
The core rod 1 has a stepped surface for limiting the movement of the housing 3.
The sliding sleeve 2 is provided with a shear screw 7 which is fixed with the core bar 1 to prevent the shell 3 from moving initially.
The size of the sealing surface between the sliding sleeve 2 and the core bar 1 is consistent with that of the sealing surface between the shell 3 and the core bar 1.
As shown in figure 3, a propellant charge 9 is arranged in a core rod 1, the ground is electrified to ignite the propellant charge 9, gas generated by combustion of the propellant charge 9 is transmitted to the inner step surface of a shell 3 through 4 vent holes of the core rod 1, the pressure of gunpowder is continuously increased, a shearing and shearing screw 7 is sheared, the shell 3 and the core rod 1 generate relative motion, an adapter 10 extrudes a bridge plug 6 to realize seat sealing, and when an O-shaped ring on the inner step surface of the shell moves to a pressure relief groove 5 of the core rod 1, the gas pressure in the core rod 1 is communicated with the outside to realize automatic pressure relief.
Because the screw 2 needs to be cut off when reaching a certain pressure, initial pressure can be established in the inner cavity of the core rod 7, so that the ignition charge 10 can be reliably combusted, the shell 6 can move when the gunpowder is just combusted, and the pressure in the gunpowder cavity is reduced too fast to ensure that the ignition charge 10 is cut off. The screws 2 are high precision shear pins that have strength to avoid damage when the string is jarred and that can shear reliably at the designed shear pressures.
Pressure balance principle: the sliding sleeve 5 and the shell 6 are connected through threads to form a whole, and as the diameters of sealing surfaces of the sliding sleeve 5 and the shell 6 influenced by well fluid are the same, the upward acting force and the downward acting force of the pressure of the well fluid acting on the sliding sleeve 5 and the shell 6 are equal, and the sliding sleeve 5 and the shell 6 are not influenced by the pressure of the well fluid any more when moving.
The method of the invention comprises the following steps:
the explosive column is installed in the core rod, the ground is electrified to ignite the explosive column, gas generated by combustion of the explosive column is transmitted to the inner step surface of the shell through 4 vent holes of the core rod, the pressure of explosive is continuously increased, the shell and the core rod move relatively, so that the bridge plug is extruded to realize seat sealing, and when an inner O-shaped ring of the shell moves to a pressure relief groove of the core rod, the gas pressure in the core rod is communicated with the outside, and automatic pressure relief is realized.
Claims (9)
1. The utility model provides an automatic pressure release balanced type setting instrument which characterized in that: the device comprises a core rod (1), a sliding sleeve (2) and a shell (3), wherein the core rod (1) is provided with an inner hole for installing a gunpowder column (9), the core rod (1) is radially provided with a vent hole (4) in a through manner, the outer wall of the core rod (1) is provided with an outer step surface for limiting the movement position of the shell (3), the outer step surface of the core rod (1) is in sealing fit with the inner wall of the shell (3), the outer wall of the lower end of the core rod (1) is provided with a pressure relief groove (5), the inner wall of the lower end of the shell (3) is provided with an inner step surface, the inner step surface of the shell (3) is positioned below the outer step surface, and the diameters of sealing surfaces of; in an initial state, the core rod (1) is fixedly connected with the sliding sleeve (2) and is in sealing fit with the inner wall of the sliding sleeve (2), the upper end of the shell (3) is fixedly connected with the sliding sleeve (2), the inner wall of the shell (3) is in sealing fit with the outer wall of the sliding sleeve (2), the inner step surface of the shell (3) is in sealing fit with the outer wall of the core rod (1), and the vent hole (4) is communicated with an annular space between the inner step surface and the outer step surface; when the bridge plug (6) is in a setting state, the sliding sleeve (2) moves downwards to the position of the outer step surface of the core rod (1) for limiting, the inner step surface of the shell (3) is positioned in the pressure relief groove (5), and a gap between the inner step surface and the pressure relief groove (5) forms a pressure relief channel.
2. The automatic pressure relief balanced setting tool of claim 1, wherein: the number of the vent holes (4) is 4, and the vent holes are arranged on the same circumference of the core rod (1).
3. The automatic pressure relief balanced setting tool of claim 2, wherein: the sliding sleeve (2) is fixedly connected with the core rod (1) through a shear screw (7).
4. The automatic pressure relief balanced setting tool of claim 3, wherein: the size of the sealing surface between the sliding sleeve (2) and the core rod (1) is consistent with that of the sealing surface between the shell (3) and the core rod (1).
5. The automatic pressure relief balanced setting tool of claim 4, wherein: all be provided with twice O shape circle (8) on sliding sleeve (2) inner wall and the outer wall, sliding sleeve (2) are through O shape circle (8) on the inner wall with core bar (1) sealed cooperation, through O shape circle (8) on the outer wall with casing (3) sealed cooperation.
6. The automatic pressure relief balanced setting tool of claim 5, wherein: two O-shaped rings (8) are arranged on the outer step surface of the core rod (1), and the outer step surface of the core rod (1) is in sealing fit with the inner wall of the shell (3) through the O-shaped rings (8).
7. The automatic pressure relief balanced setting tool of claim 6, wherein: two O-shaped rings (8) are arranged on the inner step surface of the shell (3), and the inner step surface of the shell (3) is in sealing fit with the outer wall of the core rod (1) through the O-shaped rings (8).
8. The automatic pressure relief balanced setting tool of claim 7, wherein: the sliding sleeve (2) is fixedly connected with the upper end of the shell (3) through threads.
9. The setting method of the automatic pressure relief balanced setting tool according to claim 1, characterized in that: the ground is electrified to ignite the explosive column, gas generated by combustion of the explosive column is transmitted to the step surface in the shell through the vent hole of the core rod, the pressure of the explosive is continuously increased, the shearing screw is cut off, the shell and the core rod generate relative motion, the bridge plug is extruded to realize setting, and when the inner step surface of the shell moves to the pressure relief groove of the core rod, the gas pressure in the core rod is communicated with the outside, so that automatic pressure relief is realized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911127363.0A CN110905429B (en) | 2019-11-18 | 2019-11-18 | Automatic pressure relief balanced type setting tool and setting method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911127363.0A CN110905429B (en) | 2019-11-18 | 2019-11-18 | Automatic pressure relief balanced type setting tool and setting method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110905429A CN110905429A (en) | 2020-03-24 |
| CN110905429B true CN110905429B (en) | 2020-09-11 |
Family
ID=69816973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911127363.0A Active CN110905429B (en) | 2019-11-18 | 2019-11-18 | Automatic pressure relief balanced type setting tool and setting method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110905429B (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2276554Y (en) * | 1996-09-28 | 1998-03-18 | 徐建 | Expansion type bridge plug |
| RU2447256C1 (en) * | 2010-10-05 | 2012-04-10 | Открытое акционерное общество "Татнефть" имени В.Д. Шашина | Bridge plug |
| CN202152663U (en) * | 2011-06-17 | 2012-02-29 | 中国石油天然气股份有限公司 | Bidirectional floating type setting device |
| CN104074491B (en) * | 2014-07-09 | 2016-05-18 | 中国石油集团渤海钻探工程有限公司 | Oil pipe bridge plug |
| WO2016160003A1 (en) * | 2015-04-01 | 2016-10-06 | Halliburton Energy Services, Inc. | Degradable expanding wellbore isolation device |
| CN104847304B (en) * | 2015-05-18 | 2017-04-12 | 中国石油集团渤海钻探工程有限公司 | bridge plug setting tool |
| CN107605428B (en) * | 2017-12-11 | 2019-11-26 | 中国石油天然气股份有限公司 | One kind can pressure release shut-in well bridge plug |
-
2019
- 2019-11-18 CN CN201911127363.0A patent/CN110905429B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110905429A (en) | 2020-03-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11053760B2 (en) | Setting tool | |
| US9810035B1 (en) | Disposable setting tool | |
| US3186485A (en) | Setting tool devices | |
| CN111980619B (en) | Oil pipe plug | |
| CN103821477A (en) | Self-balancing downhole safety valve | |
| CN112228005B (en) | Low setting force bridge plug capable of fishing for well lifting and pressure relief | |
| CN107816333B (en) | Underwater releasing device | |
| CN105604521B (en) | A kind of multi-functional compression type packer tubling unit experiment device | |
| CN110905429B (en) | Automatic pressure relief balanced type setting tool and setting method thereof | |
| US12012815B2 (en) | Setting tool | |
| CN204552658U (en) | Self-balancing gaseous-pressure driving bridging plug setting tool | |
| CN211448613U (en) | Self-balancing gas pressure pushing type bridge plug setting tool | |
| CN109184610B (en) | Pressure balancing device of ultra-ten thousand-meter deep well jar | |
| CN103291238A (en) | Secondary expansion patching device passing through patching pipe | |
| CN215256105U (en) | Setting tool for balancing underground pressure | |
| CN212837689U (en) | Plugging device for oil-gas well | |
| CN109667556B (en) | Hydraulic setting tool and pressure balance upper joint thereof | |
| CN219495629U (en) | Setting/differential pressure performance testing device of superhigh Wen Jiaotong assembly | |
| CN110593802A (en) | Metal sealing packing device | |
| CN211598620U (en) | Pressure channel control device | |
| CN210509105U (en) | Metal sealing packer | |
| CN106482934B (en) | Reverse circulation downhole tool opening pressure testing device and method | |
| RU2093659C1 (en) | Pipe cutter for working in wells | |
| CN217819316U (en) | Ground simulation adds annular pressure's experimental frock | |
| CN210598954U (en) | Pressure balancing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |