EP0028121A1 - Improvements relating to downhole shearers - Google Patents
Improvements relating to downhole shearers Download PDFInfo
- Publication number
- EP0028121A1 EP0028121A1 EP80303725A EP80303725A EP0028121A1 EP 0028121 A1 EP0028121 A1 EP 0028121A1 EP 80303725 A EP80303725 A EP 80303725A EP 80303725 A EP80303725 A EP 80303725A EP 0028121 A1 EP0028121 A1 EP 0028121A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- shearer
- sub member
- plungers
- locking means
- casing
- 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.)
- Withdrawn
Links
- 238000005553 drilling Methods 0.000 claims abstract description 58
- 230000036346 tooth eruption Effects 0.000 claims description 6
- 239000006096 absorbing agent Substances 0.000 claims description 5
- 230000035939 shock Effects 0.000 claims description 5
- 230000001419 dependent effect Effects 0.000 claims description 3
- 230000037431 insertion Effects 0.000 abstract 1
- 238000003780 insertion Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
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- 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
- E21B10/64—Drill bits characterised by the whole or part thereof being insertable into or removable from the borehole without withdrawing the drilling pipe
-
- 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
- E21B10/26—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers
-
- 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
- E21B10/003—Drill bits with cutting edges facing in opposite axial directions
-
- 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
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/14—Casing shoes for the protection of the bottom of the casing
-
- 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
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
Definitions
- the present invention relates to a downhole casing. shearer for use, for example, in the exploration, mining, water well and construction industries.
- Known downhole shearers comprise a drilling bit connected to the end region of an elongate rod string which serves to drive the drilling bit. Rotation of the rod string rotates the drilling bit and causes . the required hole to be drilled. As the hole is drilled deeper the length of the rod string is increased by connecting extra rod string sections to the existing rod string, as required.
- Drilling can be and is to as deep as several hundred metres and thus different types of strata have usually to be drilled through.
- Certain strata can be hostile insofar as they consist of overburdened formations which tend to close off the hole once the drilling bit has passed therethrough.
- the rod string and drilling bit are retracted and a cylindrical casing liner is inserted into the hole.
- difficulties can arise especially in the case of overburdened strata, both whilst retracting the rod string and drilling bit, and whilst inserting the liner, the overburdened strata having to be drilled away.
- the aim of the present invention is to provide a downhole casing shearer which enables the drilling bit to be easily retracted when required, and the casing liner to be easily inserted into the hole.
- a downhole casing shearer comprising a sub member and a hollow cylindrical shearer, the sub member being adapted to be connected between a drilling bit and a drilling rod string and being insertable at least partially within the shearer, releasable locking means being provided on the sub member for locking the sub member and shearer together to prevent relative rotational movement, one end region of the shearer being connectible to a cylindrical casing liner for lining the bore in which the casing shearer is used.
- the sub member is a generally cylindrical elongate member which is a snug, though slidable fit within the cylindrical shearer i.e. the external diameter of the sub member is slightly smaller than the internal diameter of the shearer.
- One end of the sub member can be screwed to the end of a section of drilling rod string and the other end of the sub member can be screwed to a drilling bit.
- the sub member is preferably made of high quality drill collar steel and has a central,axially extending through bore via which fluid for cooling purposes and for conveying away cut material, can be passed during drilling.
- the said locking means comprise a pair of plungers which are retained in recesses in the sub member and which are spring biassed by coiled compression springs within the respective recesses, towards a position in which they project from the side wall of the sub member.
- the plungers are diametrically opposed with respect to the generally cylindrical sub member and can engage in oomplimentary ports or apertures in the wall of the cylindrical shearer to thus prevent relative rotation therebetween.
- suitable recesses in the inner wall of the shearer may replace the said ports.
- the plungers are preferably cylindrical though planar plungers or plungers of any other suitable configuration may be used, and each plunger is provided with a chamfered surface so that axial movement of the sub member relative to the shearer in one direction, will cause the plungers to retract into their respective recesses.
- the said one end region of the shearer is provided both with rotational and thrust bearings for use in connecting the shearer to a conventional casing liner, and with cutting teeth or a hardened surface for reasons later discussed.
- the other end region of the shearer which is, in use, nearest the drilling bit, is also provided with cutting teeth though merely a hardened surface may be sufficient dependent upon the nature of the material which is to be drilled.
- further locking means are provided on the sub member nearer to the drilling bit end of the sub member than said first mentioned locking means.
- These further locking means are similar to the first mentioned locking means and are preferably provided at the same diametrically opposed positions on the sub member as the first mentioned locking means.
- the plungers of said further locking means are designed so as to prevent relative axial movement between said sub member and shearer in said one direction, when the plungers have engaged in said ports, chamfers on the plungers allowing these further locking means to be disengaged in the direction opposite to said one direction.
- the sub member is connected both to a drilling rod string, preferably via a shock absorber which reduces impact loading and instantaneously applied torque, and to a drilling bit.
- the sub member is locked by said first mentioned locking means to the casing shearer so that rotation of the drilling bit also rotates the casing shearer, the external dimensions of the drilling bit being smaller than the internal diameter of the cylindrical casing shearer.
- the end of the casing shearer remote from the drilling bit is secured to an end of a conventional casing liner for a bore hole, the said rotational and thrust bearings allowing the casing shearer to rotate relative to the casing liner during a drilling operation.
- drilling can commence, the drilling bit and casing shearer cutting through the strata, the cut material being fluidised by liquid or air forced through the drilling rod string, the central bore in the sub member and the drilling bit, and being conveyed away via circulation channels defined between the sub member and casing shearer, and the annular gap between the casing liner and the drilling rod string.
- the casing liner is dragged down the bore hole.
- the rod string can be retracted relative to the casing liner thus releasing said first mentioned locking means and subsequently engaging said further locking means.
- the fluidised material By pressurizing the casing liner the fluidised material can be forced between the outer wall of the shearer and liner, and the wall of the borehole to set the liner in a secure position.
- the arrangement shown in the accompanying drawings basically comprises a drilling bit 1, a drilling rod string 3 and a downhole casing shearer 5 constructed according to the present invention.
- the downhole casing shearer 5 comprises a sub member 7 and a shearer 9, both of which are made of high quality drill collar steel.
- the sub member 7 is generally cylindrical and the shearer 9 is a hollow cylindrical member the inside diameter of which is only slightly larger than both the diameter of the sub member and the external dimensions of the drilling bit 1.
- the first or upper locking means comprises two cylindrical plungers 13 and 15 which are retained in recesses 17 and 19 respectively by pins 21, the recesses being sited at diametrically opposed positions in the side wall of sub member 7 and housing compression springs 23 which bias the plungers 13,15 to the radially outward position of Figs. 2 and 3 wherein they engage in apertures 11.
- Each plunger 13,15 has a chamfered edge 25 which enables the plungers to be moved back into their respective recesses 17,19 if the sub member is moved upwards, as viewed in Fig. 3, relative to shearer 9.
- the second or lower locking means comprises two further spring biassed plungers 27 and 29 which are also diametrically opposed with respect to each other and the axes-of which are parallel to the axes of plungers 13 and 15.
- axial movement of sub member 7 relative to shearer 9 in the upwards direction as viewed in Fig. 3 causes plungers 13 and 15 to retract and disengage apertures 11 and plungers 27 and 29 to subsequently engage in apertures 11.
- Chamfered surfaces 31 provided on plungers 27 and 29 allow sub member 7 to move downwards, as viewed in Fig. 3, to re-engage the said first locking means.
- plungers 13,15,27 and 29 are illustrated as being cylindrical, they can of course be any suitable configuration e.g. planar, the only requirement being that they limit movement of the sub member relative to the shearer. Further, through apertures 11 can be replaced by suitable recesses on the inner wall of the shearer 9.
- the inside diameter of the shearer 9 is identical to the inside diameter of a conventional casing liner 32 secured to one end thereof.
- a smooth inner surface is.presented between the shearer 9 and liner 32.
- the liner 32 has however only a wall thickness which is one half tc two thirds the wall thickness of the shearer and the exposed edge of the shearer is provided with cutting teeth 33.
- Cutting teeth 35 are also provided on the other end of shearer 9 though teeth 33 and 35 can be replaced by hardened surfaces dependent upon the nature of the material being drilled.
- the connection between the shearer 9 and the liner 32 is by way of thrust bearing 37 and rotational bearing 39.
- the bearings 37 can take the strain of forcing the drilling bit 1 downwards whilst the shearer 9 rotates and liner 32 does not.
- drilling bit 1 is connected to one end of sub member 7 by a suitable screw connection, and the other end of sub member 7 is connected, also by suitable screw connections, to drilling rod string.3 via shock absorber unit 41.
- Shock absorber unit 41 reduces impact loading and torque on the bearings 37 and 39.
- This unit 41 which is a proprietory item, can however be omitted if so desired.
- the present invention thus simplifies downhole drilling removing at least some of the previously encountered problems.
Abstract
When drilling through unconsolidated overburden strata a hole can close over. Reaming while retracting the drill bit (1) may still not ensure the hole to remain open for the subsequent insertion of a casing liner (32). This problem is overcome by providing a reamer casing shoe (5) and an elongate generally cylindrical drill-collar sub-member (7) which engages in the cylindrical casing shoe wall (9), one end of the sub-member (7) being connected to a drill bit (1) and the other end to a drill rod string (3). Locking means (13, 15; 27, 29) enable the reamer casing shoe (5) and casing liner (32) to be driven down with the drill bit (1) or to be lifted with the bit (1) and drill rod string (3). A conventional casing liner (32) is connected by a rotatable connection to the trailing edge of the casing shoe (5) and thus does not rotate with it, but moves into the borehole as drilling proceeds uninhibited by unconsolidated overburden strata. The locking means (13, 15: 27, 29) can be released at the end of a drilling operation to allow the drilling bit (1), sub-member (7) and drilling rod string (3) to be retracted.
Description
- The present invention relates to a downhole casing. shearer for use, for example, in the exploration, mining, water well and construction industries.
- Known downhole shearers comprise a drilling bit connected to the end region of an elongate rod string which serves to drive the drilling bit. Rotation of the rod string rotates the drilling bit and causes . the required hole to be drilled. As the hole is drilled deeper the length of the rod string is increased by connecting extra rod string sections to the existing rod string, as required.
- Drilling can be and is to as deep as several hundred metres and thus different types of strata have usually to be drilled through. Certain strata can be hostile insofar as they consist of overburdened formations which tend to close off the hole once the drilling bit has passed therethrough. When the hole has been drilled to the required depth the rod string and drilling bit are retracted and a cylindrical casing liner is inserted into the hole. However, difficulties can arise especially in the case of overburdened strata, both whilst retracting the rod string and drilling bit, and whilst inserting the liner, the overburdened strata having to be drilled away. These difficulties clearly waste time and cost money.
- The aim of the present invention is to provide a downhole casing shearer which enables the drilling bit to be easily retracted when required, and the casing liner to be easily inserted into the hole.
- According to the present invention there is provided a downhole casing shearer comprising a sub member and a hollow cylindrical shearer, the sub member being adapted to be connected between a drilling bit and a drilling rod string and being insertable at least partially within the shearer, releasable locking means being provided on the sub member for locking the sub member and shearer together to prevent relative rotational movement, one end region of the shearer being connectible to a cylindrical casing liner for lining the bore in which the casing shearer is used.
- In a preferred embodiment of the present invention the sub member is a generally cylindrical elongate member which is a snug, though slidable fit within the cylindrical shearer i.e. the external diameter of the sub member is slightly smaller than the internal diameter of the shearer. One end of the sub member can be screwed to the end of a section of drilling rod string and the other end of the sub member can be screwed to a drilling bit. The sub member is preferably made of high quality drill collar steel and has a central,axially extending through bore via which fluid for cooling purposes and for conveying away cut material, can be passed during drilling. The said locking means comprise a pair of plungers which are retained in recesses in the sub member and which are spring biassed by coiled compression springs within the respective recesses, towards a position in which they project from the side wall of the sub member. The plungers are diametrically opposed with respect to the generally cylindrical sub member and can engage in oomplimentary ports or apertures in the wall of the cylindrical shearer to thus prevent relative rotation therebetween. Alternatively suitable recesses in the inner wall of the shearer may replace the said ports. The plungers are preferably cylindrical though planar plungers or plungers of any other suitable configuration may be used, and each plunger is provided with a chamfered surface so that axial movement of the sub member relative to the shearer in one direction, will cause the plungers to retract into their respective recesses. The said one end region of the shearer is provided both with rotational and thrust bearings for use in connecting the shearer to a conventional casing liner, and with cutting teeth or a hardened surface for reasons later discussed. The other end region of the shearer, which is, in use, nearest the drilling bit, is also provided with cutting teeth though merely a hardened surface may be sufficient dependent upon the nature of the material which is to be drilled.
- Preferably further locking means are provided on the sub member nearer to the drilling bit end of the sub member than said first mentioned locking means. These further locking means are similar to the first mentioned locking means and are preferably provided at the same diametrically opposed positions on the sub member as the first mentioned locking means. However the plungers of said further locking means are designed so as to prevent relative axial movement between said sub member and shearer in said one direction, when the plungers have engaged in said ports, chamfers on the plungers allowing these further locking means to be disengaged in the direction opposite to said one direction.
- In use, the sub member is connected both to a drilling rod string, preferably via a shock absorber which reduces impact loading and instantaneously applied torque, and to a drilling bit. The sub member is locked by said first mentioned locking means to the casing shearer so that rotation of the drilling bit also rotates the casing shearer, the external dimensions of the drilling bit being smaller than the internal diameter of the cylindrical casing shearer. Finally, the end of the casing shearer remote from the drilling bit is secured to an end of a conventional casing liner for a bore hole, the said rotational and thrust bearings allowing the casing shearer to rotate relative to the casing liner during a drilling operation.
- With the above arrangement drilling can commence, the drilling bit and casing shearer cutting through the strata, the cut material being fluidised by liquid or air forced through the drilling rod string, the central bore in the sub member and the drilling bit, and being conveyed away via circulation channels defined between the sub member and casing shearer, and the annular gap between the casing liner and the drilling rod string. As drilling proceeds so the casing liner is dragged down the bore hole. At certain points where a particular section of liner or rod string, is virtually completely within the bore hole, the rod string can be retracted relative to the casing liner thus releasing said first mentioned locking means and subsequently engaging said further locking means. Further retraction of the rod string will then retract the casing shearer and casing liner so that further sections of liner can be attached, the teeth on the upper end of the shearer clearing any blocking material. By subsequently moving the rod string down the hole relative to the liner the first mentioned locking means can be re-engaged and drilling resumed. At the end of a drilling operation the drilling rod string is moved upwards relative to the casing shearer and lining sufficient to disengage the said first mentioned locking means but not to engage the said further locking means. The drilling rod string is then rotated through less than 180° so that the plungers of the further locking means are out of alignment with the ports in the shearer wall. Retraction of the rod string then allows the drilling bit to be moved easily up the shearer and liner leaving the shearer and liner in position in the bore hole. Clearly the prior art problems are overcome.
- By pressurizing the casing liner the fluidised material can be forced between the outer wall of the shearer and liner, and the wall of the borehole to set the liner in a secure position.
- The present invention will now be further described, by way of example, with reference to the accompanying drawings, in which:-
- Fig. 1 is a perspective view of a preferred embodiment of a downhole casing shearer constructed according to the present invention;
- Fig. 2 is a perspective view of the shearer of Fig. 1 omitting the shearer casing;
- Fig. 3 is a vertical sectional view of the embodiment of Fig. 1; and
- Fig. 4 is a horizontal sectional view of the embodiment of Fig. 1 along line IV-IV.
- The arrangement shown in the accompanying drawings basically comprises a
drilling bit 1, a drilling rod string 3 and adownhole casing shearer 5 constructed according to the present invention. - The
downhole casing shearer 5 comprises asub member 7 and ashearer 9, both of which are made of high quality drill collar steel. Thesub member 7 is generally cylindrical and theshearer 9 is a hollow cylindrical member the inside diameter of which is only slightly larger than both the diameter of the sub member and the external dimensions of thedrilling bit 1. - Two sets of locking means are provided on the
sub member 7 and can engage withapertures 11 in the wall of theshearer 9. The first or upper locking means comprises twocylindrical plungers recesses pins 21, the recesses being sited at diametrically opposed positions in the side wall ofsub member 7 andhousing compression springs 23 which bias theplungers apertures 11. Eachplunger chamfered edge 25 which enables the plungers to be moved back into theirrespective recesses shearer 9. The second or lower locking means comprises two further spring biassedplungers plungers sub member 7 relative toshearer 9 in the upwards direction as viewed in Fig. 3, causesplungers apertures 11 and plungers 27 and 29 to subsequently engage inapertures 11. Chamferedsurfaces 31 provided onplungers sub member 7 to move downwards, as viewed in Fig. 3, to re-engage the said first locking means. - Whilst the
plungers apertures 11 can be replaced by suitable recesses on the inner wall of theshearer 9. - The inside diameter of the
shearer 9 is identical to the inside diameter of aconventional casing liner 32 secured to one end thereof. Thus a smooth inner surface is.presented between theshearer 9 andliner 32. Theliner 32 has however only a wall thickness which is one half tc two thirds the wall thickness of the shearer and the exposed edge of the shearer is provided with cuttingteeth 33.Cutting teeth 35 are also provided on the other end ofshearer 9 thoughteeth shearer 9 and theliner 32 is by way of thrust bearing 37 androtational bearing 39. Thus thebearings 37 can take the strain of forcing thedrilling bit 1 downwards whilst theshearer 9 rotates andliner 32 does not. - In use, as illustrated in Fig. 3,
drilling bit 1 is connected to one end ofsub member 7 by a suitable screw connection, and the other end ofsub member 7 is connected, also by suitable screw connections, to drilling rod string.3 viashock absorber unit 41.Shock absorber unit 41 reduces impact loading and torque on thebearings unit 41 which is a proprietory item, can however be omitted if so desired. - During
normal drilling plungers apertures 11 causingshearer 9 to rotate. Thus drillingbit 1 and cuttingteeth 35 cut the required bore. Cut material is fluidised and the bit and teeth cooled, by liquid forced under pressure down the rod string 3 which is hollow, throughbores 43 in theshock absorber unit 41 and thesub member 7. The fluidised material is then passed throughgrooves 45 in the outer surface of thesub member 7 and through the annular space 47 between theliner 32 and the rod string 3, to the surface. Alternatively by pressurizing theliner 32, the fluidised material can be forced between the borehole and the outer surface of the liner to set the liner in position. - When additional lengths of
liner 32 or rod string 3 have to be connected, drilling is stopped and the rod string is retracted relative toliner 32 and thusshearer 9. This movement causesplungers plungers apertures 11. Continued retraction of the rod string lifts theliner 32 andshearer 9 allowing additional liner sections to be connected. By subsequently lowering thedrilling bit 1,plungers apertures 11 and drilling can recommence.Teeth 33 allow theliner 31 andshearer 9 to be retracted even if strata have moved againstliner 31. If requiredliner 31 andshearer 9 can be fully retracted and a liner inserted, the larger-diameter ofshearer 9 allowing for any slight strata movement before the liner is inserted. However, it is intended that when drilling is complete the rod string is retracted relative toshearer 9 only sufficient to disengageplungers apertures 11 and not to engage theplungers shearer 9 are then rotated through less than 180° to bringplungers apertures 11, and the rod string 3,sub member 7 anddrilling bit 1 are fully retracted throughliner 32. Thus thecasing liner 32 is simply located and the drilling bit is easily removed. - The present invention thus simplifies downhole drilling removing at least some of the previously encountered problems.
Claims (16)
1. A downhole casing shearer for use in drilling bore holes, characterised by a sub member (7) and a hollow cylindrical shearer (9), the sub member (7) being adapted to be connected between a drilling bit (1) and a drilling rod string (3) and being insertable at least partially within the shearer (9), releasable locking means (13,15) being provided on the sub member (7) for locking the sub member (7) and shearer (9) together to prevent relative rotational movement therebetween, one end region of the shearer (9) being connectible to a cylindrical casing liner (32) for lining the bore in which the casing shearer is used.
2. A downhole casing shearer as claimed in claim 1, in which the releasable locking means (13,15) restricts axial movement of the sub member (7) relative to the shearer (9) in one direction, axial movement in the opposite direction releasing said locking means (13,15).
3. A downhole casing shearer as claimed in claim 2, in which the said locking means (13,15) comprises a pair of plungers (13,15) which project laterally from the sub member (7) and which can engage in correspondingly located apertures (11) or recesses in the shearer wall, the plungers (13,15) being retractable into recesses (17,19) within the sub member (7) against the force of a spring (23).
- 4. A downhole casing shearer as claimed in claim 3, in which the plungers (13,15) are diametrically opposed with respect to the sub member (7).
5. A downhole casing shearer as claimed in claim 3, in which the plungers (13,15) each have a chamfered edge (25) to allow axial movement of the sub member (7) relative to the shearer (9) in said one direction, to retract the plungers (13,15).
6. A downhole casing shearer as claimed in any one of claims 1 to 5, in which further locking means (27,29) are provided on the sub member (7) nearer to the drilling bit connection end of the sub member (7) than said locking means (13,15).
7. A downhole casing shearer as claimed in claim 6, in which said further locking means (27,29) comprises a pair of plungers (27,29) which project laterally from the sub member (7) and which can engage in correspondingly located apertures (11) or recesses in the shearer wall, the plungers (27,29) being retractable into recesses within the sub member (7) against the force of a spring.
8. A downhole casing shearer as claimed in claim 7, in which the plungers (27,29) of said further locking means are diametrically opposed with respect to the sub member (7).
9. A downhole casing shearer as claimed in claim 7 or 8, in which the plungers (27,29) have a chamfered edge region (31) to allow axial movement of the sub member (7) relative to the shearer (9).
10. A downhole casing shearer as claimed in claim 6 when dependent upon claim 5,- in which said further locking means comprises a pair of plungers (27,29) which project laterally from the sub member (7) and which can engage correspondingly located apertures (11) or recesses in the shearer wall (9), the plungers (27,29) being diametrically opposed with respect to the sub member (7) and being retractable into recesses within the sub member (7) against the force of a spring, each plunger (27,29) of the further locking means having a chamfered edge region (31) which allows for axial movement of the sub member (7) relative to the shearer (9), from a locked position in the axial direction opposite to said one direction.
11. A downhole casing shearer as claimed in claim 10, in which the plungers (13,15;27,29) of the two locking means are arranged with their respective axes of movement parallel to each other.
12o A downhole casing shearer as claimed in claim 11, in which the plungers (13.15;27,29) of the two locking means utilise the same apertures (11) or recesses in the shearer wall (9).
13. A downhole casing shearer as claimed in any one of the preceding claims, in which cutting teeth (33,35) are provided on at least one end edge region of the shearer (9).
14. A downhole casing shearer as claimed in any one of the preceding claims, in which a cylindrical casing liner (32) is secured to one end of the shearer (9) via rotational and thrust bearings (37,39).
15. A downhole casing shearer as claimed in any one of the preceding claims, in which one end of the sub member (7) is attached to a drilling string (3) via a shock absorber unit (41), the other end of the sub member (7) being connected to a drilling bit (1).
16. A downhole casing shearer as claimed in any one of the preceding claims, in which the sub member (7) is elongate and generally cylindrical, with at least one axially extending circulation groove (45) provided in its outer surface.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7936965 | 1979-10-25 | ||
GB7936965 | 1979-10-25 | ||
GB8012790A GB2062726B (en) | 1979-10-25 | 1980-04-18 | Downhole shearers |
GB8012790 | 1980-04-18 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0028121A1 true EP0028121A1 (en) | 1981-05-06 |
Family
ID=26273345
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP80303725A Withdrawn EP0028121A1 (en) | 1979-10-25 | 1980-10-22 | Improvements relating to downhole shearers |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0028121A1 (en) |
GB (1) | GB2062726B (en) |
NO (1) | NO803151L (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0353168A1 (en) * | 1988-07-28 | 1990-01-31 | Cogema | Method and drilling machine for examination and exploitation of the subsoil |
EP0402337A2 (en) * | 1989-06-09 | 1990-12-12 | Sandvik Aktiebolag | Drill tool |
WO1996028635A1 (en) * | 1995-03-11 | 1996-09-19 | Enterprise Oil Plc | Improved casing shoe |
US7748475B2 (en) | 2004-02-19 | 2010-07-06 | Baker Hughes Incorporated | Earth boring drill bits with casing component drill out capability and methods of use |
US7900703B2 (en) | 2006-05-15 | 2011-03-08 | Baker Hughes Incorporated | Method of drilling out a reaming tool |
US7954570B2 (en) | 2004-02-19 | 2011-06-07 | Baker Hughes Incorporated | Cutting elements configured for casing component drillout and earth boring drill bits including same |
US7954571B2 (en) | 2007-10-02 | 2011-06-07 | Baker Hughes Incorporated | Cutting structures for casing component drillout and earth-boring drill bits including same |
US8006785B2 (en) | 2004-02-19 | 2011-08-30 | Baker Hughes Incorporated | Casing and liner drilling bits and reamers |
US8245797B2 (en) | 2007-10-02 | 2012-08-21 | Baker Hughes Incorporated | Cutting structures for casing component drillout and earth-boring drill bits including same |
EP2300682A4 (en) * | 2008-06-26 | 2015-12-09 | Atlas Copco Rotex Ab Oy | Method and drilling apparatus for drilling |
CN104727749B (en) * | 2015-01-29 | 2016-10-19 | 同济大学 | Wriggling burrowing robot |
RU2751298C1 (en) * | 2020-12-15 | 2021-07-13 | Публичное акционерное общество "Татнефть" имени В.Д. Шашина | Casing string drilling device |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FI95618C (en) * | 1992-12-03 | 1998-09-03 | Jorma Jaervelae | Downhole |
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US3901331A (en) * | 1972-12-06 | 1975-08-26 | Petroles Cie Francaise | Support casing for a boring head |
-
1980
- 1980-04-18 GB GB8012790A patent/GB2062726B/en not_active Expired
- 1980-10-22 EP EP80303725A patent/EP0028121A1/en not_active Withdrawn
- 1980-10-23 NO NO803151A patent/NO803151L/en unknown
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US2239996A (en) * | 1936-05-25 | 1941-04-29 | Chappell Drilling Equipment Co | Drilling apparatus |
US3199613A (en) * | 1962-09-28 | 1965-08-10 | Shell Oil Co | Method and apparatus for drilling an underwater well |
US3343615A (en) * | 1966-08-15 | 1967-09-26 | Exxon Production Research Co | Drill collar with cutting surface |
US3552509A (en) * | 1969-09-11 | 1971-01-05 | Cicero C Brown | Apparatus for rotary drilling of wells using casing as drill pipe |
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US3901331A (en) * | 1972-12-06 | 1975-08-26 | Petroles Cie Francaise | Support casing for a boring head |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0353168A1 (en) * | 1988-07-28 | 1990-01-31 | Cogema | Method and drilling machine for examination and exploitation of the subsoil |
FR2634818A1 (en) * | 1988-07-28 | 1990-02-02 | Cogema | METHOD AND DEVICE FOR DRILLING FOR THE STUDY AND OPERATION OF BASEMENT |
WO1990001102A1 (en) * | 1988-07-28 | 1990-02-08 | Cogema | Drilling device and method for the study and exploitation of the underground |
US5125464A (en) * | 1988-07-28 | 1992-06-30 | Cogema | Drilling device for the study and exploitation of the subsoil |
EP0402337A2 (en) * | 1989-06-09 | 1990-12-12 | Sandvik Aktiebolag | Drill tool |
EP0402337A3 (en) * | 1989-06-09 | 1991-05-02 | Sandvik Aktiebolag | Drill tool |
WO1996028635A1 (en) * | 1995-03-11 | 1996-09-19 | Enterprise Oil Plc | Improved casing shoe |
US6062326A (en) * | 1995-03-11 | 2000-05-16 | Enterprise Oil Plc | Casing shoe with cutting means |
US8006785B2 (en) | 2004-02-19 | 2011-08-30 | Baker Hughes Incorporated | Casing and liner drilling bits and reamers |
US8191654B2 (en) | 2004-02-19 | 2012-06-05 | Baker Hughes Incorporated | Methods of drilling using differing types of cutting elements |
US7954570B2 (en) | 2004-02-19 | 2011-06-07 | Baker Hughes Incorporated | Cutting elements configured for casing component drillout and earth boring drill bits including same |
US8297380B2 (en) | 2004-02-19 | 2012-10-30 | Baker Hughes Incorporated | Casing and liner drilling shoes having integrated operational components, and related methods |
US7748475B2 (en) | 2004-02-19 | 2010-07-06 | Baker Hughes Incorporated | Earth boring drill bits with casing component drill out capability and methods of use |
US8167059B2 (en) | 2004-02-19 | 2012-05-01 | Baker Hughes Incorporated | Casing and liner drilling shoes having spiral blade configurations, and related methods |
US8225888B2 (en) | 2004-02-19 | 2012-07-24 | Baker Hughes Incorporated | Casing shoes having drillable and non-drillable cutting elements in different regions and related methods |
US8225887B2 (en) | 2004-02-19 | 2012-07-24 | Baker Hughes Incorporated | Casing and liner drilling shoes with portions configured to fail responsive to pressure, and related methods |
US8205693B2 (en) | 2004-02-19 | 2012-06-26 | Baker Hughes Incorporated | Casing and liner drilling shoes having selected profile geometries, and related methods |
US7900703B2 (en) | 2006-05-15 | 2011-03-08 | Baker Hughes Incorporated | Method of drilling out a reaming tool |
US8177001B2 (en) | 2007-10-02 | 2012-05-15 | Baker Hughes Incorporated | Earth-boring tools including abrasive cutting structures and related methods |
US8245797B2 (en) | 2007-10-02 | 2012-08-21 | Baker Hughes Incorporated | Cutting structures for casing component drillout and earth-boring drill bits including same |
US7954571B2 (en) | 2007-10-02 | 2011-06-07 | Baker Hughes Incorporated | Cutting structures for casing component drillout and earth-boring drill bits including same |
EP2300682A4 (en) * | 2008-06-26 | 2015-12-09 | Atlas Copco Rotex Ab Oy | Method and drilling apparatus for drilling |
CN104727749B (en) * | 2015-01-29 | 2016-10-19 | 同济大学 | Wriggling burrowing robot |
RU2751298C1 (en) * | 2020-12-15 | 2021-07-13 | Публичное акционерное общество "Татнефть" имени В.Д. Шашина | Casing string drilling device |
Also Published As
Publication number | Publication date |
---|---|
GB2062726B (en) | 1983-10-12 |
GB2062726A (en) | 1981-05-28 |
NO803151L (en) | 1981-04-27 |
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Legal Events
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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AK | Designated contracting states |
Designated state(s): AT BE CH DE FR IT LU NL SE |
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Effective date: 19811029 |
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18D | Application deemed to be withdrawn |
Effective date: 19840120 |
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Inventor name: FLETCHER, FREDERICK |