EP0735232A1 - Bohrweissel für Bohrvorgänge - Google Patents

Bohrweissel für Bohrvorgänge Download PDF

Info

Publication number
EP0735232A1
EP0735232A1 EP95302012A EP95302012A EP0735232A1 EP 0735232 A1 EP0735232 A1 EP 0735232A1 EP 95302012 A EP95302012 A EP 95302012A EP 95302012 A EP95302012 A EP 95302012A EP 0735232 A1 EP0735232 A1 EP 0735232A1
Authority
EP
European Patent Office
Prior art keywords
passage
cutter bit
drilling
nozzle
zone
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
Application number
EP95302012A
Other languages
English (en)
French (fr)
Other versions
EP0735232B1 (de
Inventor
Clifford Ross Gray
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to DE69519625T priority Critical patent/DE69519625D1/de
Priority to EP19950302012 priority patent/EP0735232B1/de
Publication of EP0735232A1 publication Critical patent/EP0735232A1/de
Application granted granted Critical
Publication of EP0735232B1 publication Critical patent/EP0735232B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • E21B10/00—Drill bits
    • E21B10/08—Roller bits
    • E21B10/18—Roller bits characterised by conduits or nozzles for drilling fluids

Definitions

  • This invention relates to cutter bits for use in drilling operations, such as in the oil and gas industry and, in particular, to a bit suitable for alleviating problems associated with running of the cutter bit into a well hole and pulling of the cutter bit from the hole.
  • Conventional cutter bits comprise a generally tubular cutter bit body provided at the bottom end thereof with a plurality of cutters for cutting the well formation.
  • the cutter bit is forged and provided at its bottom end with three legs having attached to their bottom portions, known as shirt tails, mounting pins for securing cone cutter elements made of a durable material.
  • These cutter elements may be conical and are provided with hard cutting teeth, made, for example, from tungsten carbide, for cutting a formation.
  • Through the centre of the cutter bit body is usually provided a bore through which drilling fluids are delivered at high velocity via three conduits to areas adjacent to the cutters to assist in cutting and cuttings removal.
  • the central bore is not itself directly open to the cutting face and, for this reason, a number of problems can arise when a cutter bit is being run into the hole, pulled from the hole or simply being used in cutting operations.
  • the cutter bit body will be in gauge with the walls of the hole and, therefore, as the cutter bit is run into the hole it acts as a piston which compresses material below the bottom end of the cutter bit body.
  • the only relief from the increasing pressures is leakage through zones where the cutter bit body has lesser diameter than the gauge of the hole. However, as these zones only have very small area for flow of cuttings and fluids, the flow is substantially restricted and little pressure relief is obtained.
  • the consequence of such increasing pressures is "surge" or the generation of stresses on the rock formations along the open hole section below the cutter bit. It is known in the oil and gas industry that these stresses or surge pressures cause major damage to weak formations and, more importantly, to productive reservoir sands.
  • the formation may be damaged by fracturing of the formation beneath the cutter bit during running into the hole. This problem is worsened by increasing running speeds and higher viscosity drilling fluids that cause higher pressure drop across the cutter bit. Clearly, damage to the formation, with consequential reductions in oil and gas recovery, is unacceptable to the industry for cost reasons.
  • swabbing a reverse problem known to the industry as "swabbing" occurs.
  • swabbing which results from fluid flow into the reduced pressure area caused by pulling of the cutter bit and drillstring from the hole can cause blowouts which are extremely hazardous.
  • swabbing may result in contamination of the drilling fluids by formation fluids necessitating costly treatment processes and/or increased drilling fluid cost.
  • Swabbing is most pronounced when the cutter bit or drilling stabilisers are encrusted or packed with formation cuttings. In these cases, it becomes increasingly more difficult to maintain an even hydrostatic pressure on both sides of the cutter bit because the already restricted fluid flow area past the outer circumference of the cutter bit is restricted even further.
  • Other factors that contribute to swabbing include variable viscosity drilling fluids and variation in hole diameter.
  • a yet further problem with conventional cutters is poor hole cleaning due to a poor efficiency of cuttings removal from the centre of the cutting area at the bottom of the hole.
  • Conventional cutter bits rely on the delivery of drilling fluid to the bottom of the hole for effective hole cleaning.
  • cleaning from the centre of the hole is much less efficient because cuttings become trapped in recesses between the cutters and the bottom end of the cutter bit body.
  • cutting accumulation in this area can create what is called in the industry bit balling, where the trapped cuttings restrict the rotation of the cutting cones. Bit balling has been a major problem in the industry. Thus the overall cleaning and cutting efficiency of the cutter bit is reduced.
  • a cutter bit for use in drilling operations comprising a body having a top portion and a bottom portion, the bottom portion being connected to cutting means for cutting a hole in a formation to which the cutting means is exposed and the bottom portion having a diameter which defines the circumference of said hole, characterised in that there is provided, within said circumference of said bottom portion of said body, a first opening to a first passage which, in use, communicates a first zone of a hole located below the bottom portion of the body with a second zone of the hole located above the bottom portion of the body.
  • the first passage provides a route for cuttings to escape to the surface of the hole.
  • the first passage exits the body of the cutter bit adjacent and below a connecting portion, usually a threaded portion, provided on the top portion of the cutter bit body.
  • a connecting portion usually a threaded portion
  • the first passage may be found desirable for the first passage to communicate with the second zone through one or more further passages located in the body, for example, below and adjacent the connecting thread portion.
  • the openings to the further passages need not be located at the same level and can be orientated at a variety of different angles corresponding to the trajectory of the first or further passages which ranges between 0° and 90° to the central axis of the cutter bit body.
  • the cutter bit may be provided with a plurality of cutting means.
  • the cutter bit body may be provided with one or more supply passages communicating a drilling fluid supply with an opening or openings of the cutter bit body located adjacent to the cutting means for supply of drilling fluids, such as cooling and cleaning fluids, thereto.
  • the first passage opening in the bottom portion of the cutter bit body is located in a recess defined by a plurality cutting means to readily allow transfer of cuttings and fluids from the recess to the second zone of the hole.
  • flow of cuttings and fluids through the first passage may be assisted by jetting of drilling fluids for example through a nozzle, along the trajectory of the first passage.
  • a second passage and nozzle communicates a filling fluid supply for the cutter bit with the first passage.
  • a cutter bit 1 for use in drilling operations which comprises a body 10 having a top portion 11 and a bottom portion 12, the bottom portion 12 being provided with cutting means (not shown) for cutting a formation to which the cutter bit is exposed, characterised in that, within an outer circumference 13 of the bottom portion 12 of the body 10, there is provided a first opening 14 to a first passage 15 through the body 10 to communicate a first zone 20 of a hole located below the bottom portion 12 of the body with a second zone 21 of the hole located above the bottom portion 12 of the body. In this way, cuttings and fluids located below the bottom portion of the cutter bit can be transferred from the first zone 20 to the second zone 21.
  • the cutter bit body 10 above described could be a three cone cutter bit familiar to the drilling industry with the additional provision of the first passage 15.
  • the body 10 is connected to the rest of a drillstring run into the hole by a connecting thread portion 16 provided on the top portion 11 of the body 10.
  • other connecting means may also be used.
  • the body 10 is constructed of a suitable durable material such as steel and the cutting means is comprised, for example, of three rotatable conical cutting elements which are rotatably secured by bearings on pins 30 located on leg members 31 of the cutter bit 1, two of which are shown in Figure 1.
  • the cutting elements may be fabricated from a hard material such as steel or tungsten carbide and be provided with teeth of the same material to provide a cutting action.
  • the cutting elements are rotatable in response to the revolution of the drillstring and lubricated by oil or grease supplied through port 46, one of which is shown in each of Figures 1 to 4.
  • a recess 26 is definable by the cutter elements.
  • cuttings accumulate therein, in the absence of the first passage 15, reducing both the hole cleaning and cutting efficiency of the cutter bit 1.
  • the cutter bit 1 will be an almost solid structure acting as a piston with little pressure relief and increasing the problems of surge and swab. These problems are alleviated to an appreciable extent by provision of the first passage 15. It is also desirable, for the purposes of avoiding plugging of the passage 15 with cuttings, to coat the passage 15 with a non-stick material such as teflon.
  • the trajectory of the passage 15 may also be a matter of some importance in practice.
  • the opening 24 through which cuttings and fluids exit the first passage 15 and enter the second zone 21 may be either parallel or perpendicular to a central axis 23 of the central bore 25 of the cutter bit 1.
  • first passage 15 and its opening 24 to the second zone 21 are perpendicular to the central axis 23, erosion of the hole walls may occur, where jetting of drilling fluids is conducted in accordance with the embodiment described with reference to Figure 3. This would be undesirable.
  • the trajectory of the first passage 15 is not critical to the cutter bit in its broadest aspect and it is therefore to be understood that the first passage 15 may be oriented at any angle in the range 0° to 90° to the central axis 23.
  • the passage opening 24 is parallel to the central axis 23.
  • the first passage 15 is separated by wall 27 from the central bore 25 through which drilling fluids travel via conduit 36 and nozzle 37 to a location adjacent the cutting elements.
  • the flow of drilling fluids passes through the recess 26 and into the first passage 15 thereby enhancing cuttings removal and hole cleaning.
  • the restricted flow area of the conventional cutter bit has been increased by the flow area of the first passage 15 thereby increasing pressure relief and allowing a reduction in surge and swab pressures on running into the hole or pulling from the hole of the cutter bit and drillstring.
  • Figure 2 shows a further embodiment of the invention in which the flow area for communication between the first zone 20 and the second zone 21 of the hole is increased still further by the provision of a plurality of openings, two of which openings 24 and 24a are shown. However, any desired number of openings can be employed. Opening 24a communicates with first passage 15 through a further passage 33.
  • the further passage 33 may likewise be coated with teflon to improve flow properties and reduce the risk of plugging with cuttings.
  • openings 24 and 24a be at the same level of the cutter bit body 10 or at the same trajectory as each other, though this may be found convenient for the purposes of manufacture and uniform flow distribution.
  • Figure 3 shows a further embodiment of the invention in which the flow of cuttings through first passage 15 is enhanced by jetting of drilling fluids upward through the first passage 15 to create a venturi effect that further assists in cuttings removal from the first zone 20.
  • the conduit 36 communicates through conduit 41 and nozzle 42 with the first passage 15 thereby ensuring flow of drilling fluids into the first passage. Control over jetting velocity can be obtained by suitable sizing of the conduit 41 and nozzle 42.
  • the trajectory of the jet is preferably angularly upward and in the embodiment shown is at 75° to the central axis 23 of the central bore 25 of the cutter bit 1. Although in the embodiment described only one such jet has been provided there could be provided a plurality of such jets to further enhance cuttings removal and hole cleaning.
  • the first passage 15 be designed to avoid erosion damage caused by impingement of high velocity drilling fluids on the walls 15a of the passage. With this end in view, hard facing of a portion of the first passage 15 may be required.
  • Figure 4 shows a still further embodiment of the invention which is identical in many respects to that of Figure 3 described above.
  • the nozzle 37 is absent with conduit 36 being blanked off by blank 47 at the position previously occupied by nozzle 37. Therefore, a jet of higher pressure through conduit 41 and nozzle 42 can be achieved. This facilitates removal of cuttings through the first passage 15 to the surface of the hole.
  • Figure 5 shows a still further embodiment in which conduit 36 extends downwardly a sufficient distance that the nozzle 42 is located to cause a jet of drilling fluid above and adjacent, preferably immediately adjacent, the uppermost point, A, of the path of rotation, B, of each cutter element (not shown).
  • the jet is directed along the trajectory of the first passage 15 to obtain the above described advantages.
  • nozzle 42 is in close proximity to a cutting face to which the cutter bit is exposed.
  • a venturi effect is obtained, creating a suction pressure at the cutting face which greatly assists hole cleaning.

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)
  • Earth Drilling (AREA)
EP19950302012 1995-03-27 1995-03-27 Bohrmeissel für Bohrvorgänge Expired - Lifetime EP0735232B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE69519625T DE69519625D1 (de) 1995-03-27 1995-03-27 Bohrmeissel für Bohrvorgänge
EP19950302012 EP0735232B1 (de) 1995-03-27 1995-03-27 Bohrmeissel für Bohrvorgänge

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19950302012 EP0735232B1 (de) 1995-03-27 1995-03-27 Bohrmeissel für Bohrvorgänge

Publications (2)

Publication Number Publication Date
EP0735232A1 true EP0735232A1 (de) 1996-10-02
EP0735232B1 EP0735232B1 (de) 2000-12-13

Family

ID=8221146

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19950302012 Expired - Lifetime EP0735232B1 (de) 1995-03-27 1995-03-27 Bohrmeissel für Bohrvorgänge

Country Status (2)

Country Link
EP (1) EP0735232B1 (de)
DE (1) DE69519625D1 (de)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692117A (en) * 1951-11-13 1954-10-19 Reed Roller Bit Co Drill bit
US3070182A (en) * 1961-09-21 1962-12-25 John F Runte Self-cleaning fluid circulating drill bit
US3923109A (en) * 1975-02-24 1975-12-02 Jr Edward B Williams Drill tool
US4022285A (en) * 1976-03-11 1977-05-10 Frank Donald D Drill bit with suction and method of dry drilling with liquid column
US4126194A (en) * 1977-07-11 1978-11-21 Smith International, Inc. Rock bit with extended pickup tube
GB2009286A (en) * 1977-11-21 1979-06-13 Inst Francais Du Petrole Rotary drill bits for drilling holes in the ground
GB2072243A (en) * 1980-03-24 1981-09-30 Reed Rock Bit Co Earth boring drill bit
US4372399A (en) * 1982-03-11 1983-02-08 Development Oil Tool Systems Drill bit with wedge shaped eduction jets
US4687067A (en) * 1986-05-01 1987-08-18 Smith International, Inc. Crossflow rotary cone rock bit with extended nozzles

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692117A (en) * 1951-11-13 1954-10-19 Reed Roller Bit Co Drill bit
US3070182A (en) * 1961-09-21 1962-12-25 John F Runte Self-cleaning fluid circulating drill bit
US3923109A (en) * 1975-02-24 1975-12-02 Jr Edward B Williams Drill tool
US4022285A (en) * 1976-03-11 1977-05-10 Frank Donald D Drill bit with suction and method of dry drilling with liquid column
US4126194A (en) * 1977-07-11 1978-11-21 Smith International, Inc. Rock bit with extended pickup tube
GB2009286A (en) * 1977-11-21 1979-06-13 Inst Francais Du Petrole Rotary drill bits for drilling holes in the ground
GB2072243A (en) * 1980-03-24 1981-09-30 Reed Rock Bit Co Earth boring drill bit
US4372399A (en) * 1982-03-11 1983-02-08 Development Oil Tool Systems Drill bit with wedge shaped eduction jets
US4687067A (en) * 1986-05-01 1987-08-18 Smith International, Inc. Crossflow rotary cone rock bit with extended nozzles

Also Published As

Publication number Publication date
DE69519625D1 (de) 2001-01-18
EP0735232B1 (de) 2000-12-13

Similar Documents

Publication Publication Date Title
US5553681A (en) Rotary cone drill bit with angled ramps
US6722452B1 (en) Pantograph underreamer
US6446739B1 (en) Rock drill bit with neck protection
US5775443A (en) Jet pump drilling apparatus and method
US6089336A (en) Rotary drill bits
EP0884449B1 (de) Drehbohrmeissel
US7341119B2 (en) Hydro-lifter rock bit with PDC inserts
US5547033A (en) Rotary cone drill bit and method for enhanced lifting of fluids and cuttings
US3727704A (en) Diamond drill bit
US8905162B2 (en) High efficiency hydraulic drill bit
US8312942B2 (en) Roller cone drill bits with improved fluid flow
EP0707132B1 (de) Drehbohrmeissel
EP3282083B1 (de) Haltbarer bohrmeissel zum sprenglochbohren
CN112513406B (zh) 用于移除岩石的具有固定切割器的井下工具
EP0624708A2 (de) Düsenanordnung für Fräsbohrmeissel
CN102084082A (zh) 聚晶金刚石复合片钻头刀片设计和喷嘴布置
CA2160084C (en) High flow weld-in nozzle sleeve for rock bits
US4189014A (en) Enhanced cross-flow with two jet drilling
US4512420A (en) Downhole vortex generator
US7308955B2 (en) Stabilizer arrangement
US20190136635A1 (en) Downhole Tool with Fixed Cutters for Removing Rock
US3384192A (en) Hydraulic jet bit
US5462128A (en) Cutter bit for use in drilling operations
EP0735232B1 (de) Bohrmeissel für Bohrvorgänge
CA1206144A (en) Earth-boring drill bit with rectangular nozzles

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE DK FR GB IT NL SE

17P Request for examination filed

Effective date: 19970327

17Q First examination report despatched

Effective date: 19990507

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE DK FR GB IT NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 20001213

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20001213

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20001213

Ref country code: FR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20001213

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20001213

REF Corresponds to:

Ref document number: 69519625

Country of ref document: DE

Date of ref document: 20010118

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20010313

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20010314

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010327

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
EN Fr: translation not filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20010327

26N No opposition filed