EP0452584B1 - Düse für Drehbohrmeissel - Google Patents

Düse für Drehbohrmeissel Download PDF

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Publication number
EP0452584B1
EP0452584B1 EP90308487A EP90308487A EP0452584B1 EP 0452584 B1 EP0452584 B1 EP 0452584B1 EP 90308487 A EP90308487 A EP 90308487A EP 90308487 A EP90308487 A EP 90308487A EP 0452584 B1 EP0452584 B1 EP 0452584B1
Authority
EP
European Patent Office
Prior art keywords
stream
cutting elements
drilling fluid
side wall
bore hole
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
Application number
EP90308487A
Other languages
English (en)
French (fr)
Other versions
EP0452584A1 (de
Inventor
Craig R. Ivie
David E. Pearce
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.)
ReedHycalog UK Ltd
Schlumberger Technology Corp
Original Assignee
Camco International Inc
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
Priority claimed from US07/502,046 external-priority patent/US5029656A/en
Application filed by Camco International Inc filed Critical Camco International Inc
Publication of EP0452584A1 publication Critical patent/EP0452584A1/de
Application granted granted Critical
Publication of EP0452584B1 publication Critical patent/EP0452584B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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 improved nozzle means for rotary drill bits, and more particularly to improved nozzle means for directing drilling fluid first against the side wall of the formation being cut and then underneath the roller cutters of drill bits.
  • a method to improve hole cleaning without extended flow channels is shown in SU-A-258972, forming the preamble of claim 1, where a rolling cutter drill bit has nozzle passages directed downwardly and radially outwardly against the side wall of the bore hole to strike above the bottom corner, providing an inwardly sweeping fluid stream having a high velocity across the corner and bottom of the well bore tangential to the formation surface.
  • This design serves to clean solids away from the fracture openings at the surface of the formation, reduce the hold-down pressure on the fractured cuttings, and facilitate removal of dislodged cuttings by the high velocity fluid stream.
  • the most important area of the hole to adequately clean is the corner of the hole at the juncture of the side wall with the bottom where cuttings are most likely to pack particularly in so called sticky formations. Also the corner is stronger than the flat hole bottom and is more difficult to drill. It is also important to effectively clean the rest of the hole bottom. To most effectively clean the formation it is important to achieve a high tangential velocity sweeping across the surface of the formation, both at the corner of the hole and the bottom of the hole. Also in sticky formations the cutting elements need to be cleaned to more efficiently penetrate the formation. It has been found that it is most desirable to clean the formation and the cutting elements during engagement and just prior to engagement with formation.
  • Prior art drill bits have not effectively cleaned the corner of the hole and then effectively cleaned the hole bottom because they lack a high velocity flat stream sweeping across the corner of the hole and the hole bottom in a direction tangential to the hole bottom beneath the cutting elements of an adjacent roller cutter.
  • the present invention is directed to a rotary drill bit having a plurality of roller cutters with a plurality of concentric rows of cutting elements on each cutter, and nozzle means positioned on the drill bit to direct a high velocity liquid stream in a manner to provide an improved cleaning action particularly for the corner of the hole and the bottom of the hole. It is noted that dead spots for the drilling fluid along the bottom surface of the bore hole normally occur beneath the roller cutters and particularly at bottom areas where the cutting elements engage the bottom surface.
  • a rotary drill bit for drilling a bore hole comprising: a bit body having an upper end adapted to be connected to a drill string for rotating the bit and for delivering drilling fluid to the bit, and having three integrally connected legs extending from the lower end thereof, each leg including a journal on the extending end thereof having a longitudinal axis extending downwardly and generally radially inwardly of said leg; a roller cutter mounted for rotation about the longitudinal axis of each journal and having a plurality of rows of cutting elements including an outer gage row; and a fluid channel on said bit body positioned between a pair of adjacent roller cutters closer to the bore hole side wall than to the axis of rotation of said bit and having a discharge port at a height above the intersection of the longitudinal axes of said journals with said legs for directing a stream of drilling fluid downwardly and outwardly for first striking the side wall and then being directed by the side wall in a sweeping action across the bore hole corner and bottom in a high velocity thin stream following the contour of the
  • said discharge port for said nozzle is positioned to direct drilling fluid in a stream against the side wall for striking the side wall between around 1.27 cm (1 ⁇ 2 inch) and 10.16 cm (4 inches) above the lowermost cutting elements in said gage row thereby to flatten said stream for sweeping across the bore hole bottom.
  • the arrangement according to the present invention provides high velocity high volume drilling fluid across the bore hole bottom in a tangential direction beneath the cutting elements of the roller cutters during cutting engagement of the cutting elements with the bore hole bottom while also effectively cleaning the corner of the bore hole. This is accomplished as a result of the high velocity stream first striking the side wall above the lowermost cutting elements in the gage row of an adjacent roller cutter and then sweeping across the hole corner and hole bottom and beneath the cutting elements of the adjacent roller cutter in a relatively flat high velocity tangential stream during cutting engagement of the cutting elements with the hole corner and hole bottom. As a result, an improved rate of penetration is obtained, particularly in so called "sticky" formation.
  • gage row of each roller cutter is the row that most affects the rate of penetration of the rotary drill bit.
  • the gage row normally has more cutting elements therein than the remaining rows.
  • the formation is stronger at the annular corner of the bore hole formed at the juncture of the horizontal bottom surface and the vertically extending cylindrical side surface of the bore hole formation.
  • the gage row of cutting elements is the critical row in determining the rate of penetration.
  • a so-called "interlocking" row of cutting elements is provided immediately adjacent the gage row on at least one of the three roller cutters.
  • the interlocking row includes cutting elements which are staggered and fit between the cutting elements of the gage row in radially offset relation.
  • the interlocking row of cutting elements along with the gage row are thus provided for cutting the formation at its strongest area. It is desirable that maximum cleaning action by the pressurised drilling fluid be provided particularly for the cutting elements in such gage and interlocking rows, immediately prior to and during engagement of such cutting elements with the formation.
  • EP-A-0409387 describes a roller cutter drill bit in which a high velocity stream of drilling fluid is directed against the cutting elements in the gage row to provide an increased hydraulic action first against the cutting elements in the gage row and then sequentially against the bore hole bottom generally adjacent the corner of the bore hole.
  • the present invention likewise is directed to an improved hydraulic action for the cutting elements in the gage row.
  • the drilling fluid is discharged in a direction toward an adjacent roller cutter with the center of the volume of drilling fluid first striking the side wall of the bore hole above the lowermost cutting elements of the gage row, and then turning at the hole corner to sweep inwardly underneath the cutting elements during cutting engagement of the cutting elements with the formation.
  • the stream of drilling fluid is angled against the side wall and adjacent roller cutter in such a manner that the velocity of the drilling fluid sweeping under the cutting elements is not substantially reduced after striking the side wall of the bore hole so that adequate velocity is retained for sweeping under the roller cutter in a tangential direction across the corner and bottom surfaces of the hole away from the side wall.
  • the high velocity stream after striking the side wall sweeps in a thin high volume stream beneath the cutter across the bottom hole surface to scour and clean the corner and bottom surfaces during engagement of the cutting elements.
  • the stream of drilling fluid i.e. the center of the volume of discharged drilling fluid
  • an angle of at least around five degrees and not greater than around thirty five degrees would function satisfactorily under various operating conditions.
  • the stream of drilling fluid is slanted or skewed toward an adjacent roller cutter at a sufficient angle to provide a sweeping action from the side wall underneath the cutting elements of the associated cutter in a tangential flow path across the corner and bottom surfaces of the hole for the effective cleaning of the formation during engagement of the cutting elements.
  • a slant angle toward the roller cutter of around twenty degrees has been found to be optimum for directing maximum fluid flow underneath the roller cutter and across the corner and hole bottom with minimal dispersal of the drilling fluid after striking of the side wall.
  • a slant angle of at least around ten degrees and less than around thirty five degrees has resulted in improved penetration rates under various operating conditions.
  • a rotary drill bit 10 is shown in Figure 1 comprising a central main body or shank 12 with an upwardly extending threaded pin 14.
  • Threaded pin 14 comprises a tapered pin connection adapted for threadedly engaging the female end of a drill string (not shown) which is connected to a source of drilling fluid at a surface location.
  • Main body or shank 12 is formed from three integral connected lugs defining three downwardly extending legs 16.
  • Each leg 16 has an inwardly and downwardly extending, generally cylindrical bearing journal 18 at its lower end as shown in Figure 3.
  • Roller cutters 20A, 20B, and 20C are mounted on journals 18 for rotation and each roller cutter is formed of a generally conical shape.
  • Each roller cutter 20A, 20B, and 20C comprises a generally conical body 22 having a recess therein receiving an associated bearing journal 18.
  • a plurality of generally elongate cutting elements or inserts 26 have cylindrical bodies mounted in sockets within body 22 and outer tips extending from the outer ends of inserts 26.
  • Cutting elements 26 may be made of a suitable powder metallurgy composite material having good abrasion and erosion resistant properties, such as sintered tungsten carbide in a suitable matrix. A hardness from about 85 Rockwell A to about 90 Rockwell A has been found to be satisfactory.
  • Cutting elements 26 are arranged on body 22 in concentric annular rows 28A, 28B, 28C, and 28D.
  • Row 28D is the outermost row and comprises the gage row of cutting elements 26 that determines the final diameter or gage of the formation bore hole which is generally indicated at 30.
  • Row 28C is adjacent to row 28D and comprises an interlocking row on cutter 20A.
  • Cutting elements 26 on row 28C are staggered circumferentially with respect to cutting elements 26 on row 28D and a portion of cutting elements 26 on interlocking row 28C projects within the circular cutting path of row 28D.
  • the cutting paths of the cutting elements 26 on rows 28C and 28D of roller cutter 20A overlap.
  • cutters 20B and 20C do not have interlocking rows as adjacent rows 28B are spaced substantially inward of row 28D and cutting elements 26 on row 28B do not project within the cutting path of row 28D for cutters 20B and 20C. In some instances, it may be desirable to provide two cutters or possibly all of the cutters with interlocking rows of cutting elements.
  • Bore hole 30 includes a horizontal bottom surface as portion 32 and an adjacent cylindrical side wall 34 extending vertically generally at right angles to horizontal bottom 32.
  • the corner or juncture of horizontal bottom 32 and cylindrical side wall 34 is shown at 35.
  • the cutting elements 26 on gage row 28D engage the formation in cutting relation generally at the corner or juncture 35 formed by the generally horizontal bottom 32 and the vertical side wall 34.
  • a directed nozzle fluid system is provided.
  • the fluid system includes a plurality of nozzles indicated at 36A, 36B, and 36C with a nozzle positioned on bit body 12 between each pair of adjacent roller cutters.
  • Each nozzle 36 has a drilling fluid passage 38 thereto from the drill string which provides high velocity drilling fluid for discharge from port 37.
  • nozzle 36A and roller cutter 20A are illustrated. It is to be understood that nozzles 36B and 36C function in a similar manner for respective roller cutters 20B and 20C.
  • Nozzle 36A has a nozzle body 40 defining a discharge orifice or port 37 for directing a fluid stream therefrom as shown at 44.
  • Fluid stream 44 is shown of a symmetrical cross section and having a fan angle of around five to twenty degrees for example about the entire circumference of the stream with the centerline of the volume of discharged fluid shown at 45. Other fan angles or non-symmetrical cross sections for fluid stream 44 may be provided, if desired.
  • the rotational axis of cutter 20A is shown at 46 in Figure 3 and axis 46 intersects leg 16 at point 48.
  • Nozzle 36A preferably is positioned with discharge orifice or port 37 at a height below the uppermost surface of roller cutter 20 as shown in Figure 3 and at least at a height above the intersection point 48 of the rotational axis 46 of roller cutter 20A with leg 16 as shown at H1.
  • the drilling fluid has a maximum velocity and minimal cross sectional area. As the stream or jet travels from the exit point, the stream loses velocity and increases in cross sectional area. A reduction in velocity reduces the cleaning effectiveness of the stream of drilling fluid.
  • a suitable height should provide an adequate flow zone from the distribution of the stream with a sufficient velocity and dispersion to effectively clean the cutting elements and the formation.
  • Fluid stream 44 is inclined radially outward at an angle A as shown in Figures 3 and 7 of an optimum of around fifteen degrees. Angle A may be between five degrees and thirty five degrees and function satisfactory. If angle A is over around thirty five degrees, the velocity of the drilling fluid stream 44 is materially reduced from the deflection of the stream after striking side wall 34 which is undesirable for the subsequent sweeping tangential action beneath the cutting elements during the cutting operation.
  • a height H as shown in Figure 3 of around 3.81 cm (1-11 ⁇ 2 inches) for a bit diameter of 22.23 cm (8-3/4 inches) has been found to be optimum.
  • Height H is preferably at least around 1.27 (1 ⁇ 2 inch) and may be substantially higher than 3.81 cm (11 ⁇ 2 inches) dependent somewhat on the angle A of radial inclination. With a small amount of radial inclination such as 5 degrees, a greater height of impact could be provided.
  • stream 44 is of a generally frustoconical shape from port 37 to side wall 34 as shown at 44A. After striking side wall 34, stream 44 is converted into a flat generally elliptical cross section at 44B for sweeping across the curved surface of the hole corner and hole bottom at a high velocity in a direction tangential to the surface of the formation.
  • the slant angle B as measured in a direction perpendicular to the radial plane through the axis of drill bit 10 and the nozzle exit port 37 is preferably around twenty degrees as shown particularly in Figure 4.
  • a side portion of stream 44 contacts the projecting ends of cutting elements 26 in gage row 28D and interlocking row 28C for cleaning the gage and interlocking rows immediately before the cutting elements 26 in rows 28C and 28D engage the formation in cutting relation and before impingement of the stream 44 against side wall 34.
  • stream 44 After striking side wall 34, stream 44 is directed by side wall 34 around the gage corner 35 and then inwardly across bottom surface 22 tangential to the formation surface beneath cutting elements 26 of roller cutter 20A, particularly gage row 28D and interlocking row 28C.
  • stream 44 closely follows the contour of corner 35 and bottom surface 32 in a thin high velocity stream thereby providing a relatively thin high velocity stream sweeping across corner 35 and bottom surface 32 for cleaning and scouring the surface immediately before and during cutting engagement of the cutting elements 26 of roller cutter 20A and particularly the interlocking and gage rows 28C and 28D.
  • an improved cleaning and hydraulic action is provided by the positioning and angling of a stream of drilling fluid from a discharge nozzle positioned between a pair of adjacent roller cutters.
  • the stream is inclined radially outwardly and slanted toward an adjacent roller cutter at precise predetermined angles in order to obtain the desired cleaning effect by the high velocity fluid first striking the side wall of the bore hole and then sweeping inwardly in a thin tangential stream closely following the contour of the formation around the gage corner and across the bottom surface of the bore hole beneath the cutting elements of the adjacent cutter while the cutting elements are in cutting engagement with the formation.

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  • 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)

Claims (5)

  1. Drehbohrmeissel (10) zum Bohren von Bohrlöchern (30), mit einem Meisselkörper (12), mit einem oberen Ende, welches zur Verbindung mit einem Bohrgestänge zur Drehung des Meissels und zum Zuführen eines Bohrfluidums zum Meissel ausgelegt ist, und mit drei integral verbundenen Beinen (16), welche sich vom unteren Ende des Meisselkörpers erstrecken, wobei jedes Bein (16) ein Lager (18) auf dem verlängerten Ende desselben aufweist, welches eine Längsachse hat, die sich nach unten und im wesentlichen radial nach innen vom Bein erstreckt, mit einer Bohrschneidekrone (20A,20B,20C), welche zum Drehen um die Längsachse jedes Lagers montiert ist, und eine Vielzahl von Reihen (28A,28B,28C,28D) von Schneideelementen (26), einschliesslich einer äusseren Kaliberreihe (28D), hat, und mit einem Fluidumkanal auf dem Meisselkörper, welcher zwischen einem Paar nebeneinanderliegender Bohrschneideköpfen (20A,20B) näher zur Seitenwand des Bohrloches als zur Drehachse des Meissels angeordnet ist, und eine Ausgangsöffnung (37) in einer Höhe über dem Schnittpunkt der Lagerlängsachsen mit den Beinen hat, um einen Strom von Bohrfluidum nach unten und nach aussen zu richten, damit er zuerst die Seitenwand trifft und dann von der Seitenwand in einen Schwenkvorgang über Bohrlochecke und Boden geschwenkt wird in Form eines dünnen Stromes, hoher Geschwindigkeit, welcher dem Umriss des Bohrlosses unterhalb der Schneideelemente der einen angrenzenden Bohrschneidekrone (20A) während der Schneideberührung der Schneideelemente (26) mit dem Bohrloch folgt, dadurch gekennzeichnet, dass der Fluidumkanal mit einer Düse (36A) versehen ist und, dass der Strom des Bohrfluidums in Richtung einer der Schneidkronen (20A) geneigt ist, wenn man in einer Richtung unter rechtem Winkel zum Radius des Bohrmeissels misst, wobei der Strom des Bohrfluidums radial nach aussen von dem Austrittsloch (37) unter einem Winkel (A) zwischen etwa 5° und 15° bezüglich der Drehachse des Drehbohrmeissels geneigt ist, wobei das Zentrum (45) des Volumens des ausgestossenen Bohrfluidums, während des Betriebs des Meissels im Bohrloch, zuerst die Seitenwand des Bohrloches an einer Stelle berührt, welche sich auf der Seitenwand des Bohrloches in einer Höhe (H) über den untersten Schneideelementen der Kaliberreihe befindet.
  2. Drehbohrmeissel (10) nach Anspruch 1, dadurch gekennzeichnet, dass der Strom des Bohrfluidums in Richtung der Vorderseite der nachfolgenden Bohrschneidekrone (20A) des Paares nebeneinanderliegender Bohrschneidekronen geneigt ist.
  3. Drehbohrmeissel (10) nach Anspruch 1, dadurch gekennzeichnet, dass wenigstens ein Seitenteil des Stromes des Bohrfluidums die Schneideelemente (26) in der Kaliberreihe (28D) berührt, ehe er die Seitenwand berührt.
  4. Drehbohrmeissel (10) nach Anspruch 1, dadurch gekennzeichnet, dass die Austrittsöffnung (37) für die Düse angeordnet ist, um das Bohrfluidum in einem Strom gegen die Seitenwand (34) zu richten, um die Seitenwand zwischen etwa 1,27 cm (½ Zoll) oder 10,16 cm (4 Zoll) oberhalb des untersten Schneideelementes (26) der Kaliberreihe (28D) zu treffen, um so den Strom abzuflachen und ihn über den Bohrlochboden zu schwenken.
  5. Drehbohrmeissel (10) nach Anspruch 1, dadurch gekennzeichnet, dass der Strom des Bohrfluidums in Richtung einer der nebeneinanderliegenden Bohrschneidekronen (20A) unter einem Winkel (B) von wenigstens etwa 10° und weniger als etwa 35°, gemessen in einer Richtung rechtwinklig zum Radius des Drehbohrmeissels, geneigt ist.
EP90308487A 1990-03-30 1990-08-01 Düse für Drehbohrmeissel Expired - Lifetime EP0452584B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/502,046 US5029656A (en) 1989-07-17 1990-03-30 Nozzle means for rotary drill bits
US502046 1990-03-30

Publications (2)

Publication Number Publication Date
EP0452584A1 EP0452584A1 (de) 1991-10-23
EP0452584B1 true EP0452584B1 (de) 1994-06-29

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP90308487A Expired - Lifetime EP0452584B1 (de) 1990-03-30 1990-08-01 Düse für Drehbohrmeissel

Country Status (3)

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EP (1) EP0452584B1 (de)
CA (1) CA2022495C (de)
DE (1) DE69010320T2 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9033066B2 (en) 2007-07-20 2015-05-19 Baker Hughes Incorporated Nozzles including secondary passages, drill assemblies including same and associated methods

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6142247A (en) * 1996-07-19 2000-11-07 Baker Hughes Incorporated Biased nozzle arrangement for rolling cone rock bits
US6290006B1 (en) 1998-09-29 2001-09-18 Halliburton Engrey Service Inc. Apparatus and method for a roller bit using collimated jets sweeping separate bottom-hole tracks

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4546837A (en) * 1980-03-24 1985-10-15 Reed Tool Company Drill bit having angled nozzles for improved bit and well bore cleaning
US4741406A (en) * 1980-03-24 1988-05-03 Reed Tool Company Drill bit having offset roller cutters and improved nozzles
US4369849A (en) * 1980-06-05 1983-01-25 Reed Rock Bit Company Large diameter oil well drilling bit
EP0395769A4 (en) * 1988-11-14 1991-11-06 Ministerstvo Gazovoi Promyshlennosti Sssr Boring bit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9033066B2 (en) 2007-07-20 2015-05-19 Baker Hughes Incorporated Nozzles including secondary passages, drill assemblies including same and associated methods

Also Published As

Publication number Publication date
EP0452584A1 (de) 1991-10-23
DE69010320D1 (de) 1994-08-04
CA2022495A1 (en) 1991-10-01
CA2022495C (en) 1997-09-30
DE69010320T2 (de) 1994-12-22

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