EP0192016A1 - Rotary drill bit - Google Patents
Rotary drill bit Download PDFInfo
- Publication number
- EP0192016A1 EP0192016A1 EP85850056A EP85850056A EP0192016A1 EP 0192016 A1 EP0192016 A1 EP 0192016A1 EP 85850056 A EP85850056 A EP 85850056A EP 85850056 A EP85850056 A EP 85850056A EP 0192016 A1 EP0192016 A1 EP 0192016A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- drill bit
- recess
- cutter elements
- peripheral edge
- cutting face
- 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.)
- Granted
Links
- 238000005520 cutting process Methods 0.000 claims abstract description 43
- 239000012530 fluid Substances 0.000 claims abstract description 26
- 238000005553 drilling Methods 0.000 claims abstract description 18
- 230000002093 peripheral effect Effects 0.000 claims abstract description 14
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 10
- 238000005755 formation reaction Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 2
- 230000035515 penetration Effects 0.000 claims description 2
- 239000007779 soft material Substances 0.000 claims 1
- 239000000126 substance Substances 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910001104 4140 steel Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
- E21B10/43—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/02—Core bits
- E21B10/04—Core bits with core destroying means
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/60—Drill bits characterised by conduits or nozzles for drilling fluids
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
- E21B10/56—Button-type inserts
- E21B10/567—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Processing Of Stones Or Stones Resemblance Materials (AREA)
- Earth Drilling (AREA)
Abstract
Description
- The present invention relates to drill bits for use in rotary drilling through earth formations.
- In a typical rotary drilling operation, a rotary drill bit is rotated while being advanced into a soil or rock formation. The soil or rock is cut by cutting elements on the drill bit, and these cuttings are flushed from the borehole by the circulation of drilling fluid toward the top of the borehole. The drilling fluid is delivered to the drill bit downwardly through a passage in the drill stem and is ejected outwardly through nozzles disposed in the cutting face of the drill bit. The ejected drilling fluid is directed outwardly through the nozzles at high speed to aid in cutting, and to flush the cuttings and cool the cutter elements.
- A traditional area of concern in the design of rotary drill bits of this type involves the configuration at the center of rotation of the bit cutting face where the linear speed of the cutter elements is relativelyslow.
- It has been heretofore proposed to provide a drill bit with a concave recess at the center of the cutting face. When cutting through a hard substance, a core of the substance is formed within the recess. The core is gradually broken up by cutter elements disposed within the recess and/or by an inclined surface disposed at an inner end of the recess. The inclined surface also deflects the cuttings laterally through a discharge passage in the bit body. A drill bit of that type has utility in the cutting of both hard and soft substances. In the latter, the lateral discharge passage promotes the discharge of a high volume of cuttings which might otherwise clog-up the recess; thus, cutting may proceed at a faster rate. Exemplary of drill bits of that type are the bits disclosed in US-A-2 931 630, US-A-3 727 704 and US-A-4 234 048.
- Drill bits of the above-described type are subject to certain shortcomings, however, as determined by the present inventor. For example, as the core is engaged and broken up by the inclined surface at the inner end of the recess, an unbalanced force pattern is established on the drill bit. That is, the force generatated by the contact between core and the inclined surface includes a radial component which tends to displace the drill bit from its intended travel path. As a result, it becomes difficult to cut in a predetermined straight path.
- Furthermore, in cases where the discharge passage in the bit body extends longitudinally all the way to the forward end of the bit, there may be a tendency for drilling fluid to bypass some of the cutting elements mounted on the bit. That is, such a discharge passage forms a convenient travel path for drilling fluid to travel directly from the nozzle to the annulus without contacting the cutter bits to flush and cool same.
- It is, therefore, an object of the present invention to minimize or obviate problems of the above-described sort.
- Another object is to provide a drill bit which has utility in hard and soft substances and which promotes drilling in a straight direction.
- A further object is to provide such a drill bit which minimizes tendencies for drilling fluid to bypass the cutter elements.
- An additional object is to provide a centrally recessed drill bit which fractures a core without generating appreciable unbalanced forces on the bit.
- A further object is to provide such a drill with a dam that deflects drilling fluid toward cutter elements which otherwise would be bypassed.
- The above and other objects are attained by giving the invention the characterizing features stated in the appending claims.
- The invention is described in detail in the following description with reference to the accompanying drawings in which one embodiment is shown by way of example. It is to be understood that this embodiment is only illustrative of the invention and that various modifications thereof may be made within the scope of the claims.
- In the drawings, Fig. 1 is a side elevational view, partially in longitudinal section, of a drill bit and drill string according to the present invention.
- Fig. 2 is an end view of the drill bit, depicting the series of holes for receiving cutter elements and nozzles; some of the holes remaining empty in Fig. 2 and the remaining holes being depicted as containing nozzles and cutter elements.
- Fig. 3 is a side elevational view of a cutter element employed in the drill bit.
- Fig. 4 is a longitudinal sectional view through the drill bit taken along line 4-4 of Fig. 2, with the nozzles and cutter elements being omitted for clarity.
- Fig. 5 is a side elevational view of the drill bit taken along line 5-5 of Fig. 2, with the nozzles and cutting elements being omitted for clarity.
- Fig. 6 is a cross-sectional view taken along the line 6-6 in Fig. 2 to depict a lateral discharge passage and a dam-forming ridge mounted along a trailing edge of the discharge passage.
- Depicted in Figs. 1 and 2 is a
rotary drill bit 10 mounted at the end of a drill stem 11. A plurality of small bores 12 (Fig. 2) are formed in thedrill bit body 10 which are adapted to receive cutter elements 14 (Fig. 3). Thecutter elements 14 may comprise polycrystalline diamond studs in a conventional manner. - A plurality of
larger bores 16 are provided in the drill bit for the reception ofnozzles 18 for discharging jets of drilling fluid. The drilling fluid is conducted to thenozzles 18 through apassage 20 in the drill stem 11 anddrill bit 10 which communicates withpassages 22 in the drill bit. The jet streams aid in the cutting of the formation, cooling of the drill bit cutters, and carrying of the cuttings to the top of the borehole. - The
cutting face 24 of the drill bit comprises an outerperipheral edge 26 and acentral recess 28. Theouter edge 26 slopes longitudinally inwardly (upwardly) and radially outwardly. Therecess 28 is defined byside walls 30 which are inclined longitudinally and radially inwardly. Thecutting elements 14 are positioned in theperipheral edge 26, in theside walls 30, and in afloor 32 of therecess 28. Most of thenozzles 18 are positioned in thefloor 32. - The
floor 32 of therecess 28 is of concave configuration, the floor perferably comprising a centrally located, generally frusto-conical protuberance 34. If desired, theprotuberance 34 could be of other convex shape such as semispherical for example. Holes 12A, 12B for cutting elements 14 (Fig. 2) are formed in theprotuberance 34, and theaforementioned nozzle 18A is mounted in theprotuberance 34. - The drill bit also includes a plurality of
lateral discharge passages 36 which communicate with thecentral recess 28. Thosepassages 36 include base surfaces 38 (Fig. 4) which constitute continuations of aninclined wedge face 40 of theprotuberance 34. Thepassages 36, preferably three in number, are equidistantly spaced around the longitudinal axis of the drill bit, i e at 120 degree intervals. - Each passage extends radially completely through the bit body and extends longitudinally outwardly to the
peripheral edge 26 so as to form gaps in the latter. - It will be appreciated that during a cutting operation, the earth formation is cut so as to form a conical earthen core which projects into the
central recess 28. The core is fractured by the combined action of thecutting elements 14 and theconvex protuberance 34, the former engaging the sides of the core and the apex 41 of the latter engaging the tip of the core. The convex shape of thesurface 40 of theprotuberance 34 assures that the reaction forces applied against the protuberance will be distributed around the protuberance and thus will tend to be self-balancing in the radial direction. That is, a concentration of forces at one point on the floor of the recess is avoided. As a result, the drill bit will not be caused to deviate from its intended path of travel by unbalanced forces acting on the floor of the recess. - The cuttings are discharged from the recess through the
passages 36 by the action of thesurface 40 which serves as a wedge, and by flushing fluid from thenozzles - Disposed on the cutting face of the drill bit along the
trailing edge 48 of eachlateral discharge passage 36 is a ridge 50 (Fig. 6). Theridge 50 can be formed of a hard or a soft substance, as desired. For example, theridge 50 can be formed of a hard material such as tungsten carbide or 4140 steel, or formed of a softer substance such as a soft steel (e g 1020 steel). Theridge 50 projects outwardly from the cutting face by a distance slightly less than that of thecutter elements 14 and extends longitudinally along the side wall of the recess and radially along theperipheral edge 26. - The
ridge 50 performs two important functions. Firstly, the ridge acts to dam-up drilling fluid ejected from the adjacent trailing nozzle l8B (i e, the nearest nozzle 18B spaced clockwise from theridge 50 in Fig. 2). That is, in the absence of the ridge, much of the drilling fluid emanating from that nozzle would flow into the adjacent gap in the peripheral edge (i e, the gap formed by the discharge passage) and then upwardly through the annulus. However, upon encountering theridge 50, the fluid travel is blocked, causing the fluid to rebound and flow to the adjacent cutting elements located behind the ridge, i e, the cutting elements spaced clockwise from theridge 50 in Fig. 2. - As noted earlier, the
ridges 50 project from the cuttingface 24 by a distance less than, e g, one-half, that of thecutter elements 14. The difference in such projecting distance is about equal to the expected penetration depth of the cutter elements. In this fashion, the ridge will essentially contact the formation, thereby minimizing the travel of fluid between the ridge and the formation. - A second important function of the
ridge 50 is to act as a plow to push larger cuttings from the associated discharge passage so that such cuttings do not contact and damage the cutting elements located behind the ridge. In softer substances theridges 50 may serve as cutter blades as well as plows. - In operation, the drill bit is rotated while simultaneously advanced into an earth formation. As the cutting operation progresses an earthen core is formed which is disposed within the
recess 28. The sides of the core are gradually fractured by thecutter elements 14 disposed within the recess, and the tip of the earthen core is fractured by the cutter elements disposed in the floor of the recess, as well as by theconvex protuberance 34. Engagement between the core and the protuberance is such as to establish generally radially balanced forces on the drill bit whereby the drill bit is not diverted from its intended path of travel. - The
convex protuberance 34 deflects the cuttings laterally outwardly through thedischarge passages 36. Ejection of larger chunks through the discharge passages is aided by theridges 50 which act as plows to push the chunks along. - The
ridges 50 also serve to block the escape of drilling fluid from thenozzles 18. Instead, that fluid rebounds rearwardly and flows across the cutter elements disposed behind the respective ridges in order to flush and cool those cutter elements. - It will be appreciated that the present invention minimizes the likelihood that unbalanced radial forces will be exerted against the drill bit in response to contact between the earthen core and the floor of the recess. Consequently, it is easier to maintain the drill bit in a straight path of travel.
- The presence of the
ridges 50 aids in pushing larger chunks through the lateral discharge openings and thereby minimizes the likelihood that such chunks could contact and damage the cutter elements. - It is also assured that the cutter elements will be supplied with a substantial amount of cooling and flushing fluid, since it will be difficult for such fluid to bypass the cutter elements by flowing directly into the lateral discharge openings and upwardly through the annulus, due to the presence of the ridges.
Claims (10)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE8585850056T DE3567054D1 (en) | 1985-02-19 | 1985-02-19 | Rotary drill bit |
EP85850056A EP0192016B1 (en) | 1985-02-19 | 1985-02-19 | Rotary drill bit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP85850056A EP0192016B1 (en) | 1985-02-19 | 1985-02-19 | Rotary drill bit |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0192016A1 true EP0192016A1 (en) | 1986-08-27 |
EP0192016B1 EP0192016B1 (en) | 1988-12-28 |
Family
ID=8194705
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP85850056A Expired EP0192016B1 (en) | 1985-02-19 | 1985-02-19 | Rotary drill bit |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0192016B1 (en) |
DE (1) | DE3567054D1 (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1616071A2 (en) * | 2003-04-16 | 2006-01-18 | Particle Drilling, Inc. | Drill bit |
US7757786B2 (en) | 2003-04-16 | 2010-07-20 | Pdti Holdings, Llc | Impact excavation system and method with injection system |
US7798249B2 (en) | 2003-04-16 | 2010-09-21 | Pdti Holdings, Llc | Impact excavation system and method with suspension flow control |
US7980326B2 (en) | 2007-11-15 | 2011-07-19 | Pdti Holdings, Llc | Method and system for controlling force in a down-hole drilling operation |
US7987928B2 (en) | 2007-10-09 | 2011-08-02 | Pdti Holdings, Llc | Injection system and method comprising an impactor motive device |
US7997355B2 (en) | 2004-07-22 | 2011-08-16 | Pdti Holdings, Llc | Apparatus for injecting impactors into a fluid stream using a screw extruder |
US8037950B2 (en) | 2008-02-01 | 2011-10-18 | Pdti Holdings, Llc | Methods of using a particle impact drilling system for removing near-borehole damage, milling objects in a wellbore, under reaming, coring, perforating, assisting annular flow, and associated methods |
US8113300B2 (en) | 2004-07-22 | 2012-02-14 | Pdti Holdings, Llc | Impact excavation system and method using a drill bit with junk slots |
US8342265B2 (en) | 2003-04-16 | 2013-01-01 | Pdti Holdings, Llc | Shot blocking using drilling mud |
US8485279B2 (en) | 2009-04-08 | 2013-07-16 | Pdti Holdings, Llc | Impactor excavation system having a drill bit discharging in a cross-over pattern |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2740612A (en) * | 1954-02-23 | 1956-04-03 | Phipps Orville | Two-arm rotary drill bit |
FR1197183A (en) * | 1958-05-29 | 1959-11-27 | J K Smit & Fils Ets | Improvements to diamond drill heads |
FR1363375A (en) * | 1963-05-02 | 1964-06-12 | Front sweep tool | |
FR1366092A (en) * | 1963-05-27 | 1964-07-10 | Aquitaine Petrole | Advanced rotary drilling tool |
US3938599A (en) * | 1974-03-27 | 1976-02-17 | Hycalog, Inc. | Rotary drill bit |
US4207954A (en) * | 1977-03-31 | 1980-06-17 | Compagnie Francaise Des Petroles | Core bit having axial conical core breaker |
EP0032791A1 (en) * | 1980-01-16 | 1981-07-29 | DRILLING & SERVICE U.K. LIMITED | Rotary drill bits |
GB2088443A (en) * | 1980-12-01 | 1982-06-09 | Christensen Inc | Drill bit |
EP0114016A1 (en) * | 1982-12-23 | 1984-07-25 | Etablissement public dit: CHARBONNAGES DE FRANCE | Drill bit for combined rotary and jet drilling |
US4494618A (en) * | 1982-09-30 | 1985-01-22 | Strata Bit Corporation | Drill bit with self cleaning nozzle |
-
1985
- 1985-02-19 EP EP85850056A patent/EP0192016B1/en not_active Expired
- 1985-02-19 DE DE8585850056T patent/DE3567054D1/en not_active Expired
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2740612A (en) * | 1954-02-23 | 1956-04-03 | Phipps Orville | Two-arm rotary drill bit |
FR1197183A (en) * | 1958-05-29 | 1959-11-27 | J K Smit & Fils Ets | Improvements to diamond drill heads |
FR1363375A (en) * | 1963-05-02 | 1964-06-12 | Front sweep tool | |
FR1366092A (en) * | 1963-05-27 | 1964-07-10 | Aquitaine Petrole | Advanced rotary drilling tool |
US3938599A (en) * | 1974-03-27 | 1976-02-17 | Hycalog, Inc. | Rotary drill bit |
US4207954A (en) * | 1977-03-31 | 1980-06-17 | Compagnie Francaise Des Petroles | Core bit having axial conical core breaker |
EP0032791A1 (en) * | 1980-01-16 | 1981-07-29 | DRILLING & SERVICE U.K. LIMITED | Rotary drill bits |
GB2088443A (en) * | 1980-12-01 | 1982-06-09 | Christensen Inc | Drill bit |
US4494618A (en) * | 1982-09-30 | 1985-01-22 | Strata Bit Corporation | Drill bit with self cleaning nozzle |
EP0114016A1 (en) * | 1982-12-23 | 1984-07-25 | Etablissement public dit: CHARBONNAGES DE FRANCE | Drill bit for combined rotary and jet drilling |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1616071A2 (en) * | 2003-04-16 | 2006-01-18 | Particle Drilling, Inc. | Drill bit |
US7757786B2 (en) | 2003-04-16 | 2010-07-20 | Pdti Holdings, Llc | Impact excavation system and method with injection system |
US7793741B2 (en) | 2003-04-16 | 2010-09-14 | Pdti Holdings, Llc | Impact excavation system and method with injection system |
US7798249B2 (en) | 2003-04-16 | 2010-09-21 | Pdti Holdings, Llc | Impact excavation system and method with suspension flow control |
US7909116B2 (en) | 2003-04-16 | 2011-03-22 | Pdti Holdings, Llc | Impact excavation system and method with improved nozzle |
US8342265B2 (en) | 2003-04-16 | 2013-01-01 | Pdti Holdings, Llc | Shot blocking using drilling mud |
US8162079B2 (en) | 2003-04-16 | 2012-04-24 | Pdti Holdings, Llc | Impact excavation system and method with injection system |
US8113300B2 (en) | 2004-07-22 | 2012-02-14 | Pdti Holdings, Llc | Impact excavation system and method using a drill bit with junk slots |
US7997355B2 (en) | 2004-07-22 | 2011-08-16 | Pdti Holdings, Llc | Apparatus for injecting impactors into a fluid stream using a screw extruder |
US7987928B2 (en) | 2007-10-09 | 2011-08-02 | Pdti Holdings, Llc | Injection system and method comprising an impactor motive device |
US7980326B2 (en) | 2007-11-15 | 2011-07-19 | Pdti Holdings, Llc | Method and system for controlling force in a down-hole drilling operation |
US8037950B2 (en) | 2008-02-01 | 2011-10-18 | Pdti Holdings, Llc | Methods of using a particle impact drilling system for removing near-borehole damage, milling objects in a wellbore, under reaming, coring, perforating, assisting annular flow, and associated methods |
US8485279B2 (en) | 2009-04-08 | 2013-07-16 | Pdti Holdings, Llc | Impactor excavation system having a drill bit discharging in a cross-over pattern |
Also Published As
Publication number | Publication date |
---|---|
DE3567054D1 (en) | 1989-02-02 |
EP0192016B1 (en) | 1988-12-28 |
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