STEERABLE WELL DRILLING SYSTEM
First Claim
1. A dual bit well drilling mechanism for drilling attachment to a tubular well drilling string extending from a drilling rig located at the Earth'"'"'s surface, comprising:
- a well drilling mechanism being connected with the tubular well drilling string and having a connection box;
a tubular drilling housing having a threaded connection with said connection box and defining a fluid flow passage receiving drilling fluid from the tubular well drilling string and defining a housing chamber in communication with said fluid flow passage;
a reamer bit being connected with said tubular housing and having a multiplicity of formation cutter elements mounted thereto, said reamer bit being rotated by said well drilling mechanism and defining a formation core receiving receptacle centrally thereof;
a core removal bit chamber being defined by said reamer bit and having communication with said formation core receiving receptacle;
a core removing bit being supported for rotation within said core removal bit chamber and having core cutting members supported thereby and having a cutting face oriented for engaging and removing a formation core that remains as said formation cutter elements of said reamer bit cut a wellbore into the formation, said core removing bit having a reamer bit body and a cutter retention matrix defining a plurality of spaced blade members each having a multiplicity of formation cutter members; and
a drilling fluid actuated rotary motor being supported by said reamer bit body within said tubular drilling housing and having rotary driving relation with said core removal bit.
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Accused Products
Abstract
A steerable dual drilling bit having an outer reamer bit defining a central opening and having an inner core removal bit being rotatably driven by a mud motor that is supported within a tubular housing by the outer reamer bit. The dual drilling bit is capable of being threaded to the bit box of a rotary drill string or a straight or bent housing drilling system. The dual drilling mechanism is of sufficiently limited length that it is capable is being efficiently steered for directional drilling. The reamer and core removal bits are arranged to continuously cut away a formation core and to employ the core for rotational stabilization of the reamer bit during drilling.
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Citations
20 Claims
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1. A dual bit well drilling mechanism for drilling attachment to a tubular well drilling string extending from a drilling rig located at the Earth'"'"'s surface, comprising:
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a well drilling mechanism being connected with the tubular well drilling string and having a connection box; a tubular drilling housing having a threaded connection with said connection box and defining a fluid flow passage receiving drilling fluid from the tubular well drilling string and defining a housing chamber in communication with said fluid flow passage; a reamer bit being connected with said tubular housing and having a multiplicity of formation cutter elements mounted thereto, said reamer bit being rotated by said well drilling mechanism and defining a formation core receiving receptacle centrally thereof; a core removal bit chamber being defined by said reamer bit and having communication with said formation core receiving receptacle; a core removing bit being supported for rotation within said core removal bit chamber and having core cutting members supported thereby and having a cutting face oriented for engaging and removing a formation core that remains as said formation cutter elements of said reamer bit cut a wellbore into the formation, said core removing bit having a reamer bit body and a cutter retention matrix defining a plurality of spaced blade members each having a multiplicity of formation cutter members; and a drilling fluid actuated rotary motor being supported by said reamer bit body within said tubular drilling housing and having rotary driving relation with said core removal bit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A dual bit well drilling mechanism for drilling attachment to a tubular well drilling string extending from a drilling rig located at the Earth'"'"'s surface, comprising:
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a tubular drilling housing having a threaded connection with said well drilling string and defining a fluid flow passage receiving drilling fluid from the tubular well drilling string and defining a housing chamber in communication with said fluid flow passage; a stator member being mounted in substantially fixed and sealed relation within said tubular drilling housing and defining a generally helical internal fluid flow reaction profile; a rotor member being rotatably positioned within said stator member and having a generally helical external fluid flow reaction profile for fluid flow responsive rotation of said rotor member by drilling fluid flow, said rotor member defining a central passage therethrough and defining an open end; a reamer bit being defined by said tubular drilling housing and having a multiplicity of formation cutter elements mounted thereto, said tubular drilling housing and said reamer bit being rotated by said well drilling mechanism and defining a formation core receiving receptacle centrally thereof; a core removal bit chamber being defined by said reamer bit body and being exposed to said formation core receiving receptacle; and a core removing bit being supported for rotation within said core removal bit chamber and having rotary driven relation with said rotor member, a plurality of core removal members supported thereby, said core removing bit having a cutting face oriented for engaging and removing a formation core that remains as said formation cutter elements of said reamer bit body cut a wellbore into the formation. - View Dependent Claims (14, 15, 16, 17)
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18. A method for drilling wells in consolidated earth formations, comprising:
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rotating in formation cutting engagement with an earth formation a drilling mechanism having a tubular drilling housing and a reamer bit connected with said tubular drilling housing, said reamer bit defining a cutting face and defining a downwardly facing core receiving receptacle within which a substantially cylindrical formation core left by said reamer bit is received during drilling; rotating a core removal bit within said reamer bit with a drilling fluid energized rotary motor having a tubular motor housing supported within said tubular drilling housing by said reamer bit, said core removal bit having a core cutting face exposed to said downwardly facing core receiving receptacle and in cutting engagement with a circular end of the substantially cylindrical formation core and having a retracted position within said reamer bit with its core cutting face offset from said cutting face of said reamer bit, said retracted position determining the length of the substantially cylindrical formation core; conducting drilling fluid flow through said drilling fluid energized rotary motor, through a bearing pack within said drilling fluid energized rotary motor and through said core removable bit; and discharging drilling fluid from said core removable bit into said downwardly facing core receiving receptacle at said cutting face of said core removal bit. - View Dependent Claims (19, 20)
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Specification