CN201635674U - Roller stabilizer for gas drilling - Google Patents
Roller stabilizer for gas drilling Download PDFInfo
- Publication number
- CN201635674U CN201635674U CN2010201522398U CN201020152239U CN201635674U CN 201635674 U CN201635674 U CN 201635674U CN 2010201522398 U CN2010201522398 U CN 2010201522398U CN 201020152239 U CN201020152239 U CN 201020152239U CN 201635674 U CN201635674 U CN 201635674U
- Authority
- CN
- China
- Prior art keywords
- roller
- stabilizer
- section
- rib
- setting upright
- 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.)
- Expired - Lifetime
Links
- 239000003381 stabilizer Substances 0.000 title claims abstract description 64
- 238000005553 drilling Methods 0.000 title claims abstract description 39
- 239000000956 alloy Substances 0.000 claims description 4
- 230000036346 tooth eruption Effects 0.000 claims description 4
- 239000011435 rock Substances 0.000 abstract description 3
- 230000000087 stabilizing effect Effects 0.000 abstract 1
- 238000005520 cutting process Methods 0.000 description 5
- 239000012530 fluid Substances 0.000 description 5
- 238000005096 rolling process Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 206010016256 fatigue Diseases 0.000 description 3
- 230000008676 import Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 239000008187 granular material Substances 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 238000007790 scraping Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 101100334009 Caenorhabditis elegans rib-2 gene Proteins 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
Images
Landscapes
- Earth Drilling (AREA)
Abstract
The utility model discloses a gyro wheel stabilizer for gas drilling, including the stabilizer body, be provided with four outstanding arriss of rightting along stabilizer body axial direction on the stabilizer body, the both ends head position of righting the arris is the wedge form, and it has the gyro wheel groove to open on the arris of righting along stabilizer body axial direction, and the roller shaft is fixed in the gyro wheel groove, the gyro wheel is installed on the roller shaft, just the gyro wheel salient in righting the arris surface. The utility model discloses an aspect can reduce the frictional resistance between the stabilizer and the wall of a well, reduces the moment of torsion, and on the other hand can also strengthen taking the rock ability, stabilizing drill string.
Description
Technical field
The utility model relates to a kind of gas drilling roller stabilizer when utilizing gas as the circulatory mediator drilling well in the oil gas field engineering.
Background technology
At present, in the drilling well that utilizes gas for circulatory mediator,, usually need to become dissimilar bottomhole assemblies with bottomhole assembly with one or more stabilizers for Controlling Borehole Trajectory, to reach the purpose of increasing hole angle, hold angle, drop angle, as pendulum assembly, packed hole assembly etc.In the present gas drilling, usually be that the stabilizer that the liquid drilling well is used is directly used in the gas drilling.Can there be following shortcoming like this:
Do not have the lubrication of drilling fluid during 1, owing to gas drilling in the pit shaft, the frictional resistance of the common stabilizer and the borehole wall will increase greatly, and moment of torsion also can increase, and cause stabilizer short application life, drill string fatiguability damage etc.
2, because the large rock-carrying ability of gas is strong not as the large rock-carrying ability of liquid, and common stabilizer guiding gutter is even runner, or is vertical-type, or is screw type, the landwaste handling capacity is poor, may cause taking rock and be obstructed.
Application publication number is CN101358509A, application open day was the preparation method that the Chinese patent literature on February 4th, 2009 discloses a kind of multi-functional stabilizer, be uniformly on same section cylinder of stabilizer body to offer three roller grooves, and roller shaft is installed on roller groove, is cone by roller shaft with the end, the roller that the surface is provided with cutting edge is connected on the roller groove of stabilizer body, roller and roller shaft are for flexibly connecting, the cone of roller in the front end of stabilizer body in the same way, and the circumscribed circle diameter of three rollers is greater than the diameter of axle of stabilizer body, under the situation of bit wear, can cut the borehole wall like this, thereby hole diameter is measure-alike before and after guaranteeing by cone on the roller and cutting edge.Stabilizer provided by the utility model is a kind of multi-functional stabilizer with the function set upright and reaming hole function, also have with the wall friction resistance for a short time simultaneously, abrasion resistance is strong, long service life, superiority such as security performance height, thus can drilling process can in played the purpose of synergy.
But technique scheme does not still have to solve the technical barrier of " because the large rock-carrying ability of gas is strong not as the large rock-carrying ability of liquid; common stabilizer guiding gutter is even runner, or is vertical-type, or is screw type; the landwaste handling capacity is poor, may cause taking rock and be obstructed ".
The utility model content
For solving the problems of the technologies described above, the utility model proposes a kind of a kind of gas drilling roller stabilizer that relates to when in the oil gas field engineering, utilizing gas as the circulatory mediator drilling well.The utility model can reduce the frictional resistance between the stabilizer and the borehole wall on the one hand, reduces moment of torsion, can also strengthen large rock-carrying ability on the other hand, stablizes drill string.
The utility model is realized by adopting following technical proposals:
A kind of gas drilling roller stabilizer, comprise the stabilizer body, it is characterized in that: be provided with four outstanding ribs of setting upright at stabilizer body upper edge stabilizer body axial direction, the described two ends position of setting upright rib is the wedge type shape, have roller groove on the rib along setting upright of stabilizer body axial direction, roller shaft is fixed in the described roller groove, roller is installed on the roller shaft, and described roller protrudes in the described edge surface of setting upright, the two ends of roller groove have slot cover, cover plate through screw in slot cover, and the two ends of roller shaft are fixed in the described roller groove through cover plate, the end of the described cover plate and the contacted side of the borehole wall also is the wedge type shape, the described rib of setting upright comprises straightedge section and heelpiece type scroll section, described roller groove is opened on described straightedge section, one end of straightedge section is a wedge type, the other end and scroll section are joined, the other end of described scroll section also is a wedge type, the space of setting upright between the rib forms guiding gutter, wherein guiding gutter comprises that width reduces gradually, and the wide portion straight channel that forms by space between the straightedge section, with by the narrow outlet helical flow path that forms between the heelpiece type scroll section.
Set upright rib for four and on the stabilizer body, be symmetrical arranged, and be the angle of 90 degree mutually.
The cross section of described roller groove is semicircle, and half of roller is embedded in the described semicircular roller groove, and second half protrudes in the described edge surface of setting upright.
The surface of described roller is provided with the cutting teeth of carbide alloy material, and roller is inserted type, narrow flute profile or wide flute profile.
The utility model beneficial effect shows:
1, because the utility model adopts and all to be set to the wedge type shape at the two ends position of setting upright rib, and the frictional resistance when helping reducing to raise and decentralize drilling tool between the stabilizer and the borehole wall reduces moment of torsion, back reaming unfreezing when helping carrying drilling tool and running into hole diameter and dwindle; Have roller groove on the rib setting upright, roller is set in the roller groove, back reaming unfreezing when roller set that four rolling forms and wedge type righting strip head help carrying drilling tool and run into hole diameter and dwindle; Roller will roll along the borehole wall when stabilizer body rotates, and the sliding friction of setting upright the rib scraping borehole wall is converted into rolling friction between the roller and the borehole wall, reduced greatly the stabilizer and the borehole wall frictional resistance, reduced rotation torque, prolonged the application life of lower drilling tool.The utility model roller stabilizer set upright rib, roller can be set upright drill string, reduces or eliminates the off-centre of drill string, makes drill string and well coaxial, and can reduce problems such as drill string wearing and tearing and fatigue damage.
2, the end of the cover plate and the contacted side of the borehole wall also is the wedge type shape, and such frame mode can import the cutting teeth that is provided with on the roller with the bulky grain landwaste; Be provided with on the roller carbide cutting tooth can with the bulky grain landwaste once more crushing grinding become than the granule landwaste, carried away by air-flow then; Roller is inserted type, narrow flute profile or wide flute profile, goes for different stratum, and for example inserted type roller is applicable to that abrasive layer, narrow flute profile roller are applicable to that hard formation, wide flute profile are applicable to soft formation.
3, roller is fixed on the stabilizer body by screw and cover plate, only need more renew roller behind the rolling wheel wear, and the stabilizer body can continue to use, and helps reducing drilling cost.
4, because the utility model " wherein guiding gutter comprises that width reduces gradually; and the wide portion straight channel that forms by space between the straightedge section; and by the narrow outlet helical flow path that forms between the heelpiece type scroll section " such technical scheme, the shape of guiding gutter inlet can guarantee that the landwaste that any direction and angle arrive all can enter guiding gutter, the guiding gutter entrance is the straight channel that width reduces gradually, outlet is narrow outlet helical flow path, it is the narrow export-oriented of wide portion, the wide portion straight channel of bottom helps gas like this, cutting grain enters runner smoothly and is accelerated, the narrow outlet helical flow path on top makes gas, landwaste quickens several times once more, and at outlet generation high-speed screw stream, help strengthening straight well, the horizontal well large rock-carrying ability, and routine techniques has only straight channel.These designs can set upright and stable drill string, reduce frictional resistance and rotation torque, strengthening flow large rock-carrying ability etc.
Description of drawings
The utility model is described in further detail below in conjunction with specification drawings and specific embodiments, wherein:
Fig. 1 is the utility model front view
Fig. 2 is a lateral view among Fig. 1
Fig. 3 is adjacent two expanded views of setting upright rib in the utility model.
Fig. 4 is the schematic diagram of the utility model roller and wheel shaft
Mark among the figure:
1, stabilizer body, 2, heelpiece type scroll section, 3, the straightedge section, 4, cover plate, 5, roller, 6, wedge type, 7, inlet, 8, outlet, 9, roller groove, 10, roller shaft.
The specific embodiment
Embodiment 1
The utility model discloses a kind of gas drilling roller stabilizer, comprise stabilizer body 1, be provided with four outstanding ribs of setting upright at stabilizer body 1 upper edge stabilizer body 1 axial direction, the described two ends position of setting upright rib is wedge type 6 shapes, have roller groove 9 on the rib along setting upright of stabilizer body 1 axial direction, roller shaft 10 is fixed in the described roller groove 9, and roller 5 is installed on the roller shaft 10, and described roller 5 protrudes in the described edge surface of setting upright.
Embodiment 2
As a better embodiment of the present utility model, on the basis of embodiment 1, the two ends of roller groove 9 have slot cover, cover plate 4 through screw in slot cover, and the two ends of roller shaft 10 are fixed in the described roller groove 9 through cover plate 4, and described cover plate 4 also is wedge type 6 shapes with the end of the contacted side of the borehole wall.Set upright rib for four and on stabilizer body 1, be symmetrical arranged, and be the angle of 90 degree mutually.The cross section of described roller groove 9 is semicircle, and half of roller 5 is embedded in the described semicircular roller groove 9, and second half protrudes in the described edge surface of setting upright.The surface of described roller 5 is provided with the cutting teeth of carbide alloy material, and roller 5 is inserted type, narrow flute profile or wide flute profile.
Embodiment 3
As another better embodiment of the utility model, on the basis of the foregoing description, the described rib of setting upright comprises straightedge section 3 and heelpiece type scroll section 2, described roller groove 9 is opened on described straightedge section 3, one end of straightedge section 3 is a wedge type 6, the other end and scroll section are joined, the other end of described scroll section also is a wedge type 6, the space of setting upright between the rib forms guiding gutter, wherein guiding gutter comprises that width reduces gradually, and wide portion 7 straight channel that form by space between the straightedge section 3, with by narrow outlet 8 helical flow paths that form between the heelpiece type scroll section 2.The heelpiece type that is shaped as of described scroll section.
Embodiment 4
The utility model proposes a kind of gas drilling roller stabilizer.Mainly by forming with the roller 5 of the stabilizer body 1 of special righting strip, semicircle roller groove 9, band tooth, roller shaft 10, back side wedge type 6 cover plates 4 etc.Stabilizer body 1 is a hollow cylinder, has four special shapes that are mutually 90 ° to set upright rib on cylinder.Setting upright the rib straightedge for widening gradually from the bottom up, up is heelpiece type scroll again, and helical angle is 25 °~30 °.Semicircle roller groove 9 is opened on righting strip straightedge section 3, and semicircle roller groove 9 two have slot cover.Roller 5 is installed on the roller shaft 10, and roller shaft 10 two are pushed down by back side wedge type 6 cover plates 4, and are screwed cover plate 4.
Because no drilling fluid lubricating effect in the gas drilling pit shaft, cause the increase of stabilizer and borehole wall frictional resistance, rotation torque to increase, the utility model gas drilling roller 5 stabilizers are connected on assigned address in the drill string according to the needs of drilling assembly, roller 5 will roll along the borehole wall when stabilizer body 1 rotates, the sliding friction of the righting strip scraping borehole wall is converted into rolling friction between the roller 5 and the borehole wall, reduced greatly the stabilizer and the borehole wall frictional resistance, reduced rotation torque, prolonged the application life of lower drilling tool.
The roller of installing on the utility model 5 is installed on the body through special construction by screw, and roller 5 wearing and tearing backs only need more renew roller 5, and body can continue to use, and helps reducing drilling cost.The utility model can be used different roller 5 instead according to different stratum, and roller 5 has three kinds of inserted type, narrow flute profile and wide flute profiles, and inserted type roller 5 is applicable to that abrasive layer, narrow flute profile roller 5 are applicable to that hard formation, wide flute profile are applicable to soft formation.
Two of the utility model righting strip is optimized to wedge shape, the frictional resistance when helping reducing to raise and decentralize drilling tool.Back reaming unfreezing when 5 groups on roller and wedge type 6 righting strip heads help carrying drilling tool and run into hole diameter and dwindle.The cover plate 4 of wedge type 6 shapes can import the bulky grain landwaste roller 5 teeth, the carbide alloy tooth on the roller 5 can with the bulky grain landwaste once more crushing grinding become than the granule landwaste, carried away by air-flow then.
The utility model gas drilling roller 5 stabilizers constantly change the righting strip shape by the fluid numerical simulation technology, the best guiding gutter of last optimization.The shape of guiding gutter inlet 7 can guarantee that the landwaste that any direction and angle arrive all can enter guiding gutter.The guiding gutter bottom is the straight guiding gutter that width reduces gradually, i.e. wide portion 7 narrow outlet 8 types, and top is narrow outlet 8 guiding gutters of special spiral.The wide portion 7 straight guiding gutters of bottom help gas, cutting grain and enter runner smoothly and be accelerated, and the narrow outlet 8 of the special spiral on top makes gas, landwaste quicken several times once more, and produce high-speed screws stream in outlet 8.The high-speed screw air-flow moves along the borehole wall, has strengthened the air-flow large rock-carrying ability.
Righting strip, the roller 5 of the utility model roller 5 stabilizers can be set upright drill string, reduce or eliminate the off-centre of drill string, make drill string and well coaxial, and can reduce problems such as drill string wearing and tearing and fatigue damage.
Embodiment 5
An embodiment of the present utility model, as accompanying drawing 1, shown in Figure 2, set upright rib 2, directly set upright rib 3, wedge type 6 cover plates 4, roller 5, taper and set upright rib 6, guiding gutter inlet 7, guiding gutter outlet 8, roller groove 9, roller shaft 10 etc. and form by stabilizer body 1, heelpiece type spiral.Article four, be mutually 90 ° directly set upright and have semi-circular roller groove 9 on the rib, roller 5 is enclosed within on the roller shaft 10, is installed in the roller groove 9.
Through the computational fluid dynamics numerical simulation, as accompanying drawing 1, shown in Figure 3, optimization the guiding gutter inlet 7 of special shape, guiding gutter outlet 8, near the fluid that any direction and any angle arrive all can be set upright rib 6 from wedge shape, the without hindrance guiding gutter wide portion 7 that enters, quicken through special straight channel, and enter narrower high-speed screw runner, strengthened the air-flow large rock-carrying ability.It is characterized in that forming by wide straight channel guiding gutter 7 and narrow helical flow path guiding gutter 8 two parts.
As accompanying drawing 1, Fig. 2, shown in Figure 4, can change roller 5 on roller shaft 10 according to different stratum is inserted type, narrow flute profile and wide flute profile roller 5.5 group 5 on roller rolls along the borehole wall in the drilling process, changes sliding friction into rolling friction, can reduce frictional resistance greatly, reduce rotation torque.
In gas drilling, the riding position of the utility model roller 5 stabilizers and number are united definite by drill string mechanics analysis and TRAJECTORY CONTROL.Cooperate the utility model to use, will rationally control rotating speed during gas drilling.To pay special attention to the coupling direction of this roller 5 stabilizers and drill string during use, import and export the correct cooperation of 8 directions.
The utility model is used for the oilfield drilling engineering.
Claims (4)
1. gas drilling roller stabilizer, comprise stabilizer body (1), it is characterized in that: be provided with four outstanding ribs of setting upright at stabilizer body (1) upper edge stabilizer body (1) axial direction, the described two ends position of setting upright rib is wedge type (6) shape, have roller groove (9) on the rib along setting upright of stabilizer body (1) axial direction, roller shaft (10) is fixed in the described roller groove (9), roller (5) is installed on the roller shaft (10), and described roller (5) protrudes in the described edge surface of setting upright, the two ends of roller groove (9) have slot cover, cover plate (4) through screw in slot cover, and the two ends of roller shaft (10) are fixed in the described roller groove (9) through cover plate (4), described cover plate (4) also is wedge type (a 6) shape with the end of the contacted side of the borehole wall, the described rib of setting upright comprises straightedge section (3) and heelpiece type scroll section (2), described roller groove (9) is opened on described straightedge section (3), one end of straightedge section (3) is wedge type (6), the other end and scroll section are joined, the other end of described scroll section also is a wedge type (6), the space of setting upright between the rib forms guiding gutter, wherein guiding gutter comprises that width reduces gradually, and wide portion (7) straight channel that forms by space between the straightedge section (3), with by narrow outlet (8) helical flow path that forms between the heelpiece type scroll section (2).
2. a kind of gas drilling roller stabilizer according to claim 1 is characterized in that: set upright rib for four and be symmetrical arranged on stabilizer body (1), and be the angle of 90 degree mutually.
3. a kind of gas drilling roller stabilizer according to claim 2 is characterized in that: the cross section of described roller groove (9) is for semicircle, and half of roller (5) is embedded in the described semicircular roller groove (9), and second half protrudes in the described edge surface of setting upright.
4. a kind of gas drilling roller stabilizer according to claim 1 is characterized in that: the surface of described roller (5) is provided with the cutting teeth of carbide alloy material, and roller (5) is inserted type, narrow flute profile or wide flute profile.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2010201522398U CN201635674U (en) | 2010-04-07 | 2010-04-07 | Roller stabilizer for gas drilling |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2010201522398U CN201635674U (en) | 2010-04-07 | 2010-04-07 | Roller stabilizer for gas drilling |
Publications (1)
Publication Number | Publication Date |
---|---|
CN201635674U true CN201635674U (en) | 2010-11-17 |
Family
ID=43080163
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN2010201522398U Expired - Lifetime CN201635674U (en) | 2010-04-07 | 2010-04-07 | Roller stabilizer for gas drilling |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN201635674U (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103015894A (en) * | 2013-01-21 | 2013-04-03 | 西南石油大学 | Friction and resistance reducing tool with axial crawling function |
CN104074477A (en) * | 2014-06-27 | 2014-10-01 | 浙江中锐工程机械有限公司 | Drum-shaped stabilizer for drilling machine |
CN106988688A (en) * | 2017-06-08 | 2017-07-28 | 广汉川亿石油科技有限公司 | Well cementation eddy flow rigid, hard centralizer |
CN107023266A (en) * | 2017-06-08 | 2017-08-08 | 广汉川亿石油科技有限公司 | A kind of drilling well stabilizer of double end Junk prevention bit freezing |
US10895117B2 (en) | 2018-12-28 | 2021-01-19 | Saudi Arabian Oil Company | Systems and methods for improved centralization and friction reduction using casing rods |
-
2010
- 2010-04-07 CN CN2010201522398U patent/CN201635674U/en not_active Expired - Lifetime
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103015894A (en) * | 2013-01-21 | 2013-04-03 | 西南石油大学 | Friction and resistance reducing tool with axial crawling function |
CN104074477A (en) * | 2014-06-27 | 2014-10-01 | 浙江中锐工程机械有限公司 | Drum-shaped stabilizer for drilling machine |
CN106988688A (en) * | 2017-06-08 | 2017-07-28 | 广汉川亿石油科技有限公司 | Well cementation eddy flow rigid, hard centralizer |
CN107023266A (en) * | 2017-06-08 | 2017-08-08 | 广汉川亿石油科技有限公司 | A kind of drilling well stabilizer of double end Junk prevention bit freezing |
US10895117B2 (en) | 2018-12-28 | 2021-01-19 | Saudi Arabian Oil Company | Systems and methods for improved centralization and friction reduction using casing rods |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN201635674U (en) | Roller stabilizer for gas drilling | |
US6173797B1 (en) | Rotary drill bits for directional drilling employing movable cutters and tandem gage pad arrangement with active cutting elements and having up-drill capability | |
US6321862B1 (en) | Rotary drill bits for directional drilling employing tandem gage pad arrangement with cutting elements and up-drill capability | |
EP3159475B1 (en) | Hybrid drill bits having increased drilling efficiency | |
CA2605196C (en) | Drag bits with dropping tendencies and methods for making the same | |
US5421424A (en) | Bowed out chisel insert for rock bits | |
US8899355B2 (en) | PDC drill bit with flute design for better bit cleaning | |
CN105672887A (en) | Hybrid drill bit with anti-tracking features | |
CN108915615B (en) | A kind of auxiliary improves the drilling rod of Annular Cuttings degree of sorting | |
US8028765B2 (en) | Drill bit, drilling system, and related methods | |
CN103775010B (en) | A kind of horizontal segment gas drilling hole cleaning instrument | |
US20150068816A1 (en) | Orientation of cutting element at first radial position to cut core | |
CN203531785U (en) | Centralizer using liquid to assist in cleaning cuttings bed | |
CN203129962U (en) | Bit-balling-prevention PDC (polycrystalline diamond compact) drill bit | |
CN110067516A (en) | A kind of quick washing-, which is scraped, cuts combined type broken rock PDC drill bit | |
CN101144373A (en) | Rolling wheel centralizer for gas drilling | |
US20160177630A1 (en) | Extended or raised nozzle for pdc bits | |
CN206000488U (en) | Dynamical type orients down-hole casing guide shoe | |
US9328562B2 (en) | Rock bit and cutter teeth geometries | |
US9284785B2 (en) | Drill bits having depth of cut control features and methods of making and using the same | |
US20130008724A1 (en) | Drill bit with distributed force profile | |
CN205477425U (en) | Wear -resisting chip removal drill collar | |
CN204024492U (en) | A kind of PDC steel body bit and nozzle thereof | |
CN203201476U (en) | Combined drill provided with disc cutter cutting structures on cutter wings | |
CN203729906U (en) | Rolling type drilling tool joint |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
CX01 | Expiry of patent term | ||
CX01 | Expiry of patent term |
Granted publication date: 20101117 |