CN110630186B - Titanium alloy is low erosion well drilling filter for drilling rod - Google Patents
Titanium alloy is low erosion well drilling filter for drilling rod Download PDFInfo
- Publication number
- CN110630186B CN110630186B CN201910764989.6A CN201910764989A CN110630186B CN 110630186 B CN110630186 B CN 110630186B CN 201910764989 A CN201910764989 A CN 201910764989A CN 110630186 B CN110630186 B CN 110630186B
- Authority
- CN
- China
- Prior art keywords
- filter
- hole
- drill rod
- titanium alloy
- filter tube
- 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
- 238000005553 drilling Methods 0.000 title claims abstract description 53
- 229910001069 Ti alloy Inorganic materials 0.000 title claims abstract description 19
- 230000003628 erosive effect Effects 0.000 title claims abstract description 16
- 239000000725 suspension Substances 0.000 claims description 29
- 239000000463 material Substances 0.000 claims description 9
- 238000001914 filtration Methods 0.000 claims description 5
- 238000003466 welding Methods 0.000 claims description 5
- 239000012530 fluid Substances 0.000 abstract description 27
- 230000000694 effects Effects 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910052755 nonmetal Inorganic materials 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910001149 41xx steel Inorganic materials 0.000 description 1
- 241000251468 Actinopterygii Species 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
- B01D29/31—Self-supporting filtering elements
-
- 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
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/006—Accessories for drilling pipes, e.g. cleaners
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
- Filtering Materials (AREA)
Abstract
The invention discloses a low-erosion drilling filter for a titanium alloy drill rod, which is different from a traditional filter, wherein a thread structure is arranged on the inner wall of a filter pipe, and a plurality of filter holes are arranged along the spiral direction of each spiral groove; the filter holes of the spiral structure are arranged, so that when high-pressure drilling fluid flows to a drill rod through the filter holes of the filter, the drilling fluid is ejected from the filter holes tangentially or obliquely relative to the inner wall of the drill rod from the filter direction instead of being vertically or nearly vertically ejected to the inner wall of the drill rod through the plurality of filter holes, namely, the flow velocity direction of the high-pressure drilling fluid flowing through the filter is adjusted, and the high-pressure drilling fluid ejected from the filter holes is prevented from being ejected to the inner wall of the drill rod in the vertical or nearly vertical direction to erode the inner wall of the drill rod, so that the erosion effect of the high-pressure drilling fluid on the inner wall of the drill rod when the high-pressure drilling fluid passes through the filter is effectively relieved, the risk of puncture failure or fracture failure of the drill rod due to the.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to the field of drilling tools, in particular to a low-erosion drilling filter for a titanium alloy drill rod.
[ background of the invention ]
In the exploration and development of petroleum and natural gas, a drilling column is combined to form a slurry channel for conveying drilling fluid for a drill bit. During drilling, the mud needs to be pressurized by a mud pump to meet the drilling fluid column pressure required to balance the formation/reservoir pressure for drilling. During the pressurizing and conveying process of the drilling fluid, because the pump and the conveying pipeline need to use non-metal materials, such as paraffine rubber, broken non-metal materials or other impurities often enter the drilling fluid, and especially when a screw drilling tool using underground power or a drill bit using a small nozzle is used, the cleanliness of the drilling fluid is required to be stricter so as to prevent the impurities from blocking a water hole of the underground power drilling tool or the drill bit, so that the tool is damaged or pulled out too early, and the drilling cost is increased and the risk of underground complexity is caused. Therefore, drilling fluid is typically cleaned by placing a drilling filter within the nipple of the drill pipe. The conventional filter has the defects that the high-pressure drilling fluid beam is vertically or nearly vertically emitted to the inner wall of the drill rod, so that the inner wall of the drill rod is seriously eroded to form an erosion pit, the inner wall of the drill rod is punctured seriously to cause puncture failure of the drill rod, even the drill rod is broken and failed at the erosion pit position, the underground fish of the drill rod is caused, and serious drilling accidents are caused. Because the hardness of the titanium alloy drill rod material is lower than that of the steel drill rod material, the titanium alloy drill rod material is more easily eroded to form an erosion pit.
[ summary of the invention ]
The invention aims to overcome the defects of the prior art and provides a low-erosion drilling filter for a titanium alloy drill rod; the filter effectively relieves the erosion effect of the high-pressure drilling fluid on the inner wall of the drill rod when the high-pressure drilling fluid passes through the filter by adjusting the flow velocity direction of the high-pressure drilling fluid flowing through the filter, reduces the risk of puncture failure or fracture failure of the drill rod due to the filter, and improves the service life and the safety of the drill rod.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
a low erosion drilling filter for a titanium alloy drill rod is characterized by comprising a suspension head and a filter tube which are fixedly connected, wherein the suspension head is communicated with the interior of the filter tube; spiral grooves are formed in the inner wall of each filter tube, a plurality of filter holes are arrayed in each spiral groove along the spiral direction of the spiral groove, and the axes of the filter holes are perpendicular to the tangent plane of the bottom surface of each spiral groove.
The invention is further improved in that:
preferably, the suspension head comprises an upper through hole and a lower through hole which are communicated and coaxial, and the diameter of the lower through hole is larger than that of the upper through hole; the upper through hole has the same inner diameter as the filter tube, and the lower through hole is fixedly connected with the upper end of the filter tube.
Preferably, the diameter of the lower through hole is 0.1-0.3mm larger than the outer diameter of the filter tube; the suspension head and the filter tube are connected by welding.
Preferably, the height of the lower through hole is 3.8-4.0 mm.
Preferably, the filter tube is provided with a hole along the axial direction, and the hole is communicated with the upper through hole and has the same diameter.
Preferably, the groove depth of the spiral groove is 0.7-0.9mm, and the thread pitch is 500-600 mm.
Preferably, the spiral groove is a multi-start spiral with 2-4 starts.
Preferably, the diameter of the filter holes is 8-10 mm.
Preferably, the straight line distance between the axes of the adjacent filter holes in the same spiral groove is more than 2 times of the diameter of the filter hole.
Preferably, the material hardness of the filter tube is more than or equal to HRC 35.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a low-erosion drilling filter for a titanium alloy drill rod, which is different from a traditional filter, wherein a spiral groove structure is arranged on the inner wall of a filter pipe, and a plurality of filter holes are arranged along the spiral direction of each spiral groove; the filter holes of the spiral structure are arranged, so that when high-pressure drilling fluid flows to a drill rod through the filter holes of the filter, the drilling fluid is ejected from the filter holes tangentially or obliquely relative to the inner wall of the drill rod from the filter direction instead of being vertically or nearly vertically ejected to the inner wall of the drill rod through the plurality of filter holes, namely, the flow velocity direction of the high-pressure drilling fluid flowing through the filter is adjusted, and the high-pressure drilling fluid ejected from the filter holes is prevented from being ejected to the inner wall of the drill rod in the vertical or nearly vertical direction to erode the inner wall of the drill rod, so that the erosion effect of the high-pressure drilling fluid on the inner wall of the drill rod when the high-pressure drilling fluid passes through the filter is effectively relieved, the risk of puncture failure or fracture failure of the drill rod due to the.
Further, the suspension head comprises an upper through hole and a lower through hole, the upper through hole is communicated with the interior of the filter tube, so that filtered liquid can flow into the filter tube, and the upper end of the filter tube is inserted into the lower through hole and is fixedly connected with the lower through hole.
Furthermore, the diameter of the through hole at the lower part is larger than the outer diameter of the filter tube, so that the filter tube can be inserted into the suspension head and then welded for fixation, and the filter tube and the suspension head are firmly connected.
Furthermore, the height of the lower through hole is 3.8-4.0mm, so that the lower through hole has enough depth to be fixedly connected with the filter tube.
Furthermore, the inside of the filter tube is provided with a hole communicated with the upper through hole.
Further, the screw thread inside the filter tube can be set according to the quantity requirement of filter holes.
Furthermore, the distance between the filter holes is more than 2 times of the diameter of the filter holes, and meanwhile, the material of the filter tube is limited, so that the filter tube is guaranteed to have good erosion resistance.
[ description of the drawings ]
FIG. 1 is a schematic view of a low erosion well filter for a drill pipe according to the present invention;
FIG. 2 is a cross-sectional view of the suspension head of the present invention;
FIG. 3 is a cross-sectional view of a filter tube of the present invention;
wherein: 1-hanging a head; 2-a filter tube; 3-welding seams; 11-upper through hole; 12-lower through holes; 21-filtration pores; 22-outer wall; 23-helical groove; 24-holes.
[ detailed description ] embodiments
The invention is described in further detail below with reference to the following figures and specific examples:
in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and encompass, for example, both fixed and removable connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The invention discloses a low-erosion drilling filter for a titanium alloy drill rod, which comprises a suspension head 1 and a filter tube 2, wherein the suspension head 1 is welded with the filter tube 2; the suspension head 1 and the filter tube 2 are coaxial.
Referring to fig. 2, the suspension head 1 is provided with two coaxial through holes with different diameters along the axial direction, the two through holes are an upper through hole 11 and a lower through hole 12 which are communicated with each other, and the diameter of the lower through hole 12 is larger than that of the upper through hole 11; the diameter of the upper through hole 11 is the same as the inner diameter of the filter tube 2, and the diameter of the lower through hole 12 is larger than the outer diameter of the filter tube 12; the height of the lower through hole 12 is 3.8-4.0 mm.
Referring to fig. 1 and 3, the filter tube 2 is a circular tube structure, a hole 24 is formed in the filter tube along the axial direction of the filter tube, the upper end of the hole 24 is open, the upper end of the hole 24 is the upper end of the filter tube 2, and the bottom of the hole 24 is the bottom of the filter tube 2; the diameter of the hole 24 is equal to that of the upper through hole 12, the diameter of the lower through hole 12 is 0.2-0.5mm larger than the outer diameter of the filter tube 2, the structure enables the upper end of the whole filter tube 2 to be inserted into the lower through hole 12, and when the filter tube 2 is fixedly connected with the suspension head 1, the inner wall of the hole 24 and the inner wall of the upper through hole 12 can form a smooth inner wall of the through hole; because the filter tube 2 and the suspension head 1 are welded, when the filter tube 2 and the suspension head 2 are fixedly connected, the hole 24 is aligned with the inner wall of the upper through hole 12, the lower through hole 12 is 0.1-0.3mm larger than the outer diameter of the filter tube 2, the filter tube can be inserted into the suspension head, and then the filter tube and the suspension head are fixed by welding seams, so that the filter tube and the suspension head can be firmly connected.
Referring to fig. 1 and 3, the outer wall 22 of the filter tube 2 is cylindrical, the inner wall of the hole 24 is multi-head spiral, the multi-head spiral groove 23 is 2-4 heads, the groove depth is 0.7-0.9mm, and the thread pitch of the spiral groove 23 is 500-600 mm; the whole filter tube 2 is provided with a plurality of filter holes 21 on each spiral groove 23, the filter holes on one spiral groove 23 are arranged in an array mode along the spiral direction of the spiral groove 23, the diameter of each filter hole 21 is 8-10mm, and the axes of the filter holes 21 are all vertical to the section of the bottom surface of the spiral groove 23, namely the wall surface of the filter tube 2; the distance between the axes of two adjacent filtering holes 21 in the same spiral groove 23 is more than 2 times of the diameter of the filtering holes 21; the bottom of the hole 24 is also provided with a filter hole 21 for discharging drilling oil, and the hardness of the material of the filter pipe 2 is more than or equal to HRC 35; the wall thickness of the filter tube 2 is 3.5-4.0 mm.
The filter of the invention can also be used for steel drill pipes or drill pipes made of other materials.
The working process is as follows:
when the drilling fluid passes through the filter and is sprayed into the drill pipe, the drilling fluid firstly enters the hole 24 through the upper through hole 11 of the suspension head 1, the flowing direction of the drilling fluid from the filter is not vertical or nearly vertical to the inner wall of the drill pipe any more, but the drilling fluid is tangentially or obliquely sprayed out of the filter holes relative to the inner wall of the drill pipe through the plurality of filter holes 21, and the drilling fluid which is not sprayed out finally flows out through the filter holes 21 at the bottom.
Example 1
The low-erosion drilling filter for the titanium alloy drill rod comprises a suspension head 1 and a filter tube 2, wherein the suspension head of the filter is connected with the filter tube in a welding mode, and the suspension head 1 is a circular ring piece. The specific dimensions of the filter are as follows:
the outer diameter of the suspension head 1 is 78mm, the diameter of the upper through hole 11 is 62.1mm, the height of the suspension head 1 is 5mm, the diameter of the lower through hole 11 is 69.6mm, and the depth is 3.9 mm; the suspension head 1 is made of low-alloy structural steel 42 CrMo.
The outer diameter of the filter tube 2 is 69.1mm, and the inner diameter is 62.1 mm; the diameter of the filter holes 21 on the filter tube 2 is 8mm, and the linear distance between the axes of the adjacent filter holes 21 in the same spiral direction is 18 mm; 3 spiral grooves 23 are formed in the inner wall of the filter tube 2, and the groove depth of each spiral groove 23 is 0.8 mm; the pitch of the spiral groove 23 is 550 mm; the direction of the filter holes 21 on the filter tube 2 is consistent with the spiral direction of the spiral groove 23; the material of filter tube 2 was 4145H with a hardness of HRC 36.
The filter of this embodiment is suitable for a 127mm x 9.19mm S135IEU drill pipe joint, the internal diameter of which is 69.9 mm.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (8)
1. The low-erosion drilling filter for the titanium alloy drill rod is characterized by comprising a suspension head (1) and a filter tube (2) which are fixedly connected, wherein the suspension head (1) is communicated with the interior of the filter tube (2); spiral grooves are formed in the inner wall of the filter tube (2), a plurality of filter holes (21) are arrayed in each spiral groove (23) along the spiral direction of the spiral groove, and the axes of the filter holes (21) are perpendicular to the tangent plane of the bottom surface of each spiral groove (23);
the spiral groove (23) is a multi-head spiral with 2-4 heads;
the straight line distance between the axes of the adjacent filtering holes (21) in the same spiral groove (23) is more than 2 times of the diameter of the filtering holes (21).
2. The titanium alloy drill pipe low erosion drilling filter as claimed in claim 1, wherein the suspension head (1) comprises an upper through hole (11) and a lower through hole (12) which are communicated and coaxial, and the diameter of the lower through hole (12) is larger than that of the upper through hole (11); the inner diameters of the upper through hole (11) and the filter tube (2) are the same, and the lower through hole (12) is fixedly connected with the upper end of the filter tube (2).
3. The titanium alloy drill pipe low-erosion drilling filter as claimed in claim 2, wherein the diameter of the lower through hole (12) is 0.1-0.3mm larger than the outer diameter of the filter tube (2); the suspension head (1) and the filter tube (2) are connected by welding.
4. A titanium alloy drill pipe low erosion drill filter as claimed in claim 2 wherein the lower through hole (12) has a height of 3.8-4.0 mm.
5. The titanium alloy drill pipe low-erosion drilling filter as claimed in claim 2, wherein the filter pipe (2) is provided with a hole (24) along the axial direction, and the hole (24) is communicated with the upper through hole (11) and has the same diameter.
6. The low erosion drill filter for titanium alloy drill pipe as set forth in claim 1, wherein the spiral groove (23) has a groove depth of 0.7-0.9mm and a thread pitch of 500-600 mm.
7. A titanium alloy drill pipe low erosion drill filter as claimed in claim 1, wherein the diameter of the filter holes (21) is 8-10 mm.
8. The titanium alloy drill pipe low erosion drilling filter as claimed in any one of claims 1 to 7, characterized in that the material hardness of the filter tube (2) is greater than or equal to HRC 35.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910764989.6A CN110630186B (en) | 2019-08-19 | 2019-08-19 | Titanium alloy is low erosion well drilling filter for drilling rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910764989.6A CN110630186B (en) | 2019-08-19 | 2019-08-19 | Titanium alloy is low erosion well drilling filter for drilling rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110630186A CN110630186A (en) | 2019-12-31 |
| CN110630186B true CN110630186B (en) | 2021-05-28 |
Family
ID=68970576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910764989.6A Active CN110630186B (en) | 2019-08-19 | 2019-08-19 | Titanium alloy is low erosion well drilling filter for drilling rod |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110630186B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116065972B (en) * | 2023-04-06 | 2023-06-06 | 山西风雷钻具有限公司 | Ocean drilling high-strength high-toughness titanium alloy drill rod |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7303029B2 (en) * | 2004-09-28 | 2007-12-04 | Intelliserv, Inc. | Filter for a drill string |
| CN201358760Y (en) * | 2009-03-05 | 2009-12-09 | 菲时特科技(天津)有限公司 | Oil and gas production pipe |
| CN201696014U (en) * | 2010-06-21 | 2011-01-05 | 成都百施特金刚石钻头有限公司 | Efficient self-cleaning flow regulation device |
| CN206138831U (en) * | 2016-09-22 | 2017-05-03 | 中石化石油工程技术服务有限公司 | Can pacify drilling fluid filter unit who tears open fast |
| CN206409215U (en) * | 2017-01-24 | 2017-08-15 | 贺玉华 | DC drill rod filter |
| CN208686323U (en) * | 2018-07-09 | 2019-04-02 | 中国石油集团渤海钻探工程有限公司 | Huge discharge dual stage shoulder boring rod filter |
-
2019
- 2019-08-19 CN CN201910764989.6A patent/CN110630186B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110630186A (en) | 2019-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20160230510A1 (en) | Intake manifold | |
| CN110630186B (en) | Titanium alloy is low erosion well drilling filter for drilling rod | |
| CN1329619C (en) | System to reduce hydrostatic pressure in risers using buoyant spheres | |
| CN107401378A (en) | Drill bit | |
| US4809778A (en) | Oil well tool for in situ release of wellbore treatment fluid | |
| CN106507861B (en) | Two-tube single action core drill | |
| EP2868860A1 (en) | Drill string component | |
| CN211974915U (en) | Circulating rotational flow washing tool in large-inclination oil well | |
| CN207278193U (en) | drill bit | |
| CN206903590U (en) | A kind of new six wings PDC drill bit of band cone tooth | |
| CN207278215U (en) | Counterflush drilling device | |
| CN206903589U (en) | A kind of new five wings PDC drill bit of band cone tooth | |
| CN104612583A (en) | Hydraulic hammer flow diversion mechanism, hydraulic hammer and down-hole drilling rig | |
| CN204804790U (en) | Sand -prevention screening tube | |
| CN113279405A (en) | Sleeve drilling system | |
| CN112983430A (en) | Stratum freezing device | |
| CN206830060U (en) | A kind of high intensity three wings drilling rod | |
| CN206722764U (en) | A kind of new four wings PDC drill bit of band cone tooth | |
| CN115506727B (en) | Diameter-variable drilling tool stabilizer | |
| US20180266201A1 (en) | Venturi jet basket assembly for use in a wellbore and methods for use | |
| CN107676047A (en) | A kind of well shaping feature type drilling rod | |
| CN207110991U (en) | A kind of well cleaning function type drilling rod | |
| CN219733332U (en) | Drilling and milling dredging well repairing tool | |
| CN210509090U (en) | Rope coring drilling tool for loose coal seam drilling | |
| CN210888862U (en) | Lengthened column-cone structure pilot hole fish finding and shoe milling tool |
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 |