Method and apparatus for preventing and detecting rotary drill bit failure |
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| 申请号 | US45180074 | 申请日 | 1974-03-18 | 公开(公告)号 | US3913686A | 公开(公告)日 | 1975-10-21 |
| 申请人 | HALLIBURTON CO; | 发明人 | MANSON JR CHARLES D; | ||||
| 摘要 | Methods and apparatus for preventing the failure of a rotary drill bit as a result of the roller cutters thereof becoming jammed when drilling out disposable materials blocking a string of conduit. A drillable core which includes an abutment formed therein for engaging the roller cutters of the drill bit is provided in the string of conduit below the disposable materials. | ||||||
| 权利要求 | 1. A method, of preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed when drilling through a first material blocking a conduit and remaining jammed during continued drilling through a softer second material blocking said conduit, comprising the step of: a. drilling through an interrupted annular portion of a core of hardness greater than said second softer material, so that when said interrupted annular portion is drilled the roller cutters of said drill bit impact with lateral portions of said interrupted annular portion so as to forcibly urge said roller cutters to rotate; and b. concurrently drilling through said softer second material. 2. A method of preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed when drilling through a first material blocking a conduit and remaining jammed during continued drilling through a softer second material blocking said coNduit, comprising the steps of: a. disposing, within said softer second material blocking said conduit, a core of drillable material, said core including an annular portion of hardness greater than said softer second material, and a plurality of openings located in and essentially symmetrically about the central axis of said portion; and b. drilling through said portion during said continued drilling through said softer second material. 3. The method of claim 2, wherein: said conduit is oil well casing; said first material is casing cementing tools; and said softer second material is casing cement. 4. The method of claim 2 wherein the number of said openings is at least two but not more than four. 5. The method of claim 4 wherein the number of said openings is three. 6. A method of preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed when drilling through a first material blocking a conduit and remaining jammed during continued drilling through a second softer material blocking said conduit, comprising the steps of: a. applying a plurality of distinct rotational impact forces to said roller cutters during drilling of said second softer material, so as to forcibly urge said roller cutters to rotate; and b. generating a signal in response to jammed condition of any of said roller cutters during said drilling of said second softer material. 7. Apparatus, for preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed while drilling through a first material blocking a conduit and remaining jammed during continued drilling through a softer second material blocking said conduit, comprising: a. a housing adapted to be connected in said string of conuit; and b. a drillable core rigidly attached within said housing, said core including an interrupted annular portion of hardness greater than said softer second material. 8. The apparatus of claim 7 wherein said drillable core is formed of concrete. 9. The apparatus of claim 7 wherein the number of interruptions in said portion is at least two but no more than four. 10. The apparatus of claim 7 wherein all interruption of said portion are symmetrically placed about the central axis of said annular core. 11. The apparatus of claim 10 wherein the number of said interruptions is three and said interruptions recesses are symmetrically placed about the central axis of said annular core. 12. The apparatus of claim 10 wherein the number of said interruptions is four and said interruptions are symmetrically placed about the central axis of said annular core. 13. Apparatus, for preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed while drilling through cementing tools and remaining jammed during continued drilling through casing cement below said cementing tools contained with a string of casing, comprising: a. a housing adapted to be connected in said string of casing below said cementing tools; and b. a drillable core rigidly attached within said housing, said core having a longitudinal axis and including an interrupted annular portion of hardness greater than said casing cement. 14. The apparatus of claim 13 wherein said housing is an integral part of a combination tool and is placed below drillable cementing equipment. 15. The apparatus of claim 13 wherein said housing encloses said drillable cementing tools and said interrupted annular portion of core is formed of concrete. 16. The apparatus of claim 13 wherein said portion includes at least one substantially radially extending raised portion formed on the upper end thereof. 17. The apparatus of claim 13 wherein said opening has a substantially rectangular cross-sectional shape. 18. The apparatus of claim 17 wherein said symmetrically lobed non-circular bore has at least two but not more than four symmetrical lobes. 19. The apparatus of claim 18 wherein said symmetrically lobed non-circular axial bore has a trilobal cross-sectional shape. 20. The apparatus of claim 18 wherein said symmetrically lobed non-circular axial bore has a quadrilobal cross-sectional shape. 21. An apparatus, for preventing the failure of a rotary drill bit as a result of roller cutters thereof becoming jammed while drilling through cementing tools in a casing string and remaining jammed during continued drilling of casing cement below said cementing tools, comprising: a. a housing adapted to be connected in said casing string below said cementing tools; and b. a drillable core rigidly attached within said housing, said core having a longitudinal axis, a symmetrically lobed non-circular bore and an outer impact portion about said bore, said portion being harder than said casing cement. |
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