Well bore data-transmission apparatus with debris clearing apparatus

Abstract

In the representative embodiment of the apparatus of the present invention disclosed herein, a first ported or grooved cylindrical member is coaxially disposed within a drill string for directing drilling fluids flowing through the apparatus along one or more selected flow paths .[.through.]. .Iadd.and .Iaddend.a second ported or grooved cylindrical member .[.which.]. is coaxially arranged in the drill string adjacent to the first member for rotation in a transverse plane cutting the flow paths to cyclically obstruct these flow paths. An electric motor is cooperatively coupled by a shaft to the rotatable member for driving this member at a selected speed for developing an acoustic signal of a desired frequency as the flow paths are momentarily obstructed at periodic intervals. To prevent jamming of the flow-controlling members which would otherwise occur should debris carried in the circulating drilling fluid become lodged therebetween, the rotating member is cooperatively coupled to the motor shaft to move away from the other member in response to significant increase in the torque required to drive the rotating member. Moreover, upon an increase of the pressure differential across the two members as might occur by an accumulation of debris or the like between the two members tending to at least slow the rotating member, the other member is arranged to move away from the rotating member. Biasing means are respectively provided to maintain the flow-controlling members in their normal positions as well as to restore the two members to their normal operating positions adjacent to one another once the debris has been cleared from between the members by the continued flow of the drilling fluid.

What is claimed is: 
     
       1. Apparatus adapted for transmitting data signals from a well bore to the surface and comprising: a body adapted for connection in a pipe string and having a fluid passage arranged to carry debris-bearing fluids between the surface and well bore;   a first signal-producing member cooperatively arranged in said fluid passage for directing at least a portion of a fluid flowing therethrough along at least one selected flow path;   first means including a second signal-producing member cooperatively arranged in said fluid passage adjacent to said first member for rotation at a selected speed in a plane transverse to said flow path for repetitively obstructing said flow path at periodic intervals to cyclically produce acoustic data signals in a fluid flowing through said fluid passage;   second means operable upon at least slowing of said second member below said selected speed in response to an increase in driving torque on said second member for momentarily separating one of said signal-producing members to allow fluid-borne solids flowing through said fluid passage to pass downstream of said signal-producing members; and   third means operable upon at least slowing of said second member in response to an increased pressure differential across said signal-producing members for momentarily separating the other of said signal-producing members from said one signal-producing member to allow fluid-borne solids flowing through said fluid passage to pass downstream of said signal-producing members.   
     
     
       2. The apparatus of claim 1 wherein said first means include a rotatable motor, and a rotatable shaft drivingly coupled to said motor; said second means include means cooperatively coupling said second member to said shaft for rotation thereby as well as for movement therealong between an operating position adjacent to said first member and a debris-clearing position more distant therefrom, and first biasing means normally biasing said second member toward its said operating position and yieldable in response to an increased driving torque for said second member characteristic of the slowing of the rotational speed of said second member for allowing said second member to move at least momentarily toward its said debris-clearing position; and said third means include means cooperatively coupling said first member to said body for movement in said fluid passage between an operating position adjacent to said second member and a debris-clearing position more distant therefrom, and second biasing means normally biasing said first member toward its said operating position and yieldable in response to an increased pressure differential characteristic of the slowing of the rotational speed of said second member for allowing said first member to move at least momentarily toward its said debris-clearing position. 
     
     
       3. The apparatus of claim 2 wherein said first biasing means include spring means urging said second member toward its said operating position, and means responsive to pressure forces on said second member urging said second member toward its said operating position. 
     
     
       4. The apparatus of claim 2 wherein said second biasing ameans include spring means urging said first member toward its said operating position, and means responsive to pressure forces on said first member normally urging said first member toward its said operating position and responsive to an increased pressure differential across said signal-producing members for overcoming said spring means and urging said first member toward its said debris-clearing position. 
     
     
       5. The apparatus of claim 2 wherein said motor is a selectively-reversible electric motor; and further including circuit means responsive to the slowing of said second member for selectively reversing the rotational direction of said motor. 
     
     
       6. The apparatus of claim 5 wherein said circuit means are selectively operable for alternately reversing the rotational direction of said motor back and forth so long as said second member is slowed below said selected speed. 
     
     
       7. Apparatus adapted for transmitting data to the surface during the drilling of a borehole and comprising: a body adapted for connection in a tubular drill string and having a fluid passage arranged to conduct drilling fluids between the surface and a borehole-drilling device dependently coupled therebelow;   a flow director cooperatively arranged for movement in said fluid passage and including at least one opening for directing drilling fluids flowing through said fluid passage along a selected axis;   a signal-producing member coaxially arranged for rotation in said fluid passage and including a plurality of alternately-disposed openings and obstructions angularly spaced from one another and respectively adapted to successively cut across said axis upon rotation of said signal-producing member for cyclically producing acoustic data signals in a drilling fluid flowing through said fluid passage;   motor means adapted for rotating said signal-producing member at at least one selected rotational speed;   torque-responsive means selectively coupling said motor means to said signal-producing member and operable in response to at least slowing of said signal-producing member by fluid-borne debris for momentarily moving said signal-producing member away from said flow director when there is an increase in driving torque on said signal-producing member to allow such debris to be carried away by drilling fluids flowing through said fluid passage; and   pressure-responsive means normally maintaining said flow director in an operating position adjacent to said signal-producing member and operable in response to an increase in pressure differential across said .[.signal-producing member causing.]. .Iadd.flow director caused by .Iaddend.at least slowing of said signal-producing member for momentarily moving said flow director away from said signal-producing member to allow such debris to be carried away by drilling fluids flowing through said fluid passage.   
     
     
       8. The apparatus of claim 7 further including control means coupled to sid motor means and responsive to slowing of said signal-producing member below said selected speed for also rotatively moving said signal-producing member back and forth in relation to said flow director so long as said signal-producing member is slowed below said selected speed. 
     
     
       9. The apparatus of claim 8 wherein said motor means include a reversible electric motor; and said control means include means operable upon slowing of said motor for producing an electric signal, and means responsive to said electrical signal for repetitively reversing said motor. 
     
     
       10. The apparatus of claim 7 wherein said torque-responsive means include a rotatable shaft cooperatively coupled to said motor means for rotation thereby, .[.cluth.]. .Iadd.clutch .Iaddend.means adapted for releasably coupling said shaft to said signal-producing member for rotation thereby upon rotation of said motor means, and biasing means cooperatively arranged on said clutch means for co-rotatively coupling said shaft to said signal-producing member only so long as the torque developed by said motor means does not exceed a predetermined magnitude. 
     
     
       11. The apparatus of claim 10 wherein said clutch means include first and second axially spaced, longitudinally undulating opposed surfaces respectively arranged around sid shaft and said signal-producing member, and a plurality of rolling members movably disposed between said opposed surfaces and adapted to remain between the more widely spaced portions thereof so long as said developed torque does not exceed said predetermined magnitude for maintaining said signal-producing member in close proximity to said flow director and to move between the more closely spaced portions of said opposed surfaces when said developed torque exceeds said predetermined torque for moving said signal-producing member away from said flow director. 
     
     
       12. Apparatus adapted for measuring at least one downhole condition while drilling a borehole and comprising: a body tandemly coupled in a tubular drill string having a borehole-drilling device dependently coupled thereto and defining a fluid passage for circulating drilling fluids between the surface and said borehole-drilling device;   data-signaling means on said body and adapted for producing electrical signals representative of at least one downhole condition;   acoustic-signaling means on said body and including an electric motor coupled to said data-signaling means for selective rotation in response to said electrical signals, a flow-directing member operatively disposed in said fluid passage for movement between longitudinally spaced positions therein and having a plurality of spaced openings cooperatively arranged for directing drilling fluids in selected fluid paths along said fluid passage, and a rotatable flow-obstructing member in said fluid passage and having a plurality of alternately distributed angularly spaced openings and obstructions cooperatively arranged to successively cross said fluid paths upon rotation of said flow-obstructing member for producing cyclic acoustic signals representative of said electrical signals in drilling fluids flowing through said fluid passage;   torque-responsive means cooperatively coupling said flow-obstructing member to said motor for rotation thereby at .Iadd.at .Iaddend.at least one selected rotational speed and responsive to an increase in the torque required to maintain said flow-obstructing member at said selected speed for moving said flow-obstructing member longitudinally away from said flow-directing member upon slowing of said flow-obstructing member to clear fluid-borne debris from between said members; and   differential pressure-responsive means responsive to an increased pressure differential across said .[.flow-obstructing.]. .Iadd.flow-directing .Iaddend.member for moving said flow-directing member away from said flow-obstructing member upon slowing of said flow-obstructing member to cler such fluid-borne debris from between sid members.   
     
     
       13. The apparatus of claim 12 further including control means coupled to said motor and responsive to slowing of said flow-obstructing member below said selected speed for alternately rotating said motor back and forth in opposite rotative directions so long as said flow-obstructing member is slowed below said selected speed. 
     
     
       14. The apparatus of claim 12 wherein said flow-obstructing member is upstream of said flow-directing member. 
     
     
       15. The apparatus of claim 12 wherein said differential pressure-responsive means include pressure-biasing means operable upon increased pressure differentials across said members for shifting said flow-directing member along said fluid passage away from said flow-obstructing member and operable upon the subsequent decrease in such increased pressure differentials for shifting said flow-directing member along said fluid passage toward said flow-obstructing member. 
     
     
       16. The apparatus of claim 15 further including control means coupled to said motor and responsive to slowing of said flow-obstructing member below said selected speed for alternately rotating said motor back and forth in opposite rotative directions so long as said flow-obstructing member is slowed below said selected speed. 
     
     
       17. The apparatus of claim 12 wherein said flow-directing member is coaxially arranged in said fluid passage downstream of said flow-obstructing member. 
     
     
       18. Apparatus adapted for measuring at least one downhole condition while drilling a borehole and comprising: a body tandemly coupled in a tubular drill string having a borehole-drilling device dependently coupled thereto and defining a fluid passage for circulating drilling fluids between the surface and said borehole-drilling device;   data-signaling means on said body and adapted for producing electrical signals representative of at least one downhole condition;   acoustic-signaling means on said body and including an electric motor coupled to said data-signaling means for selective rotation in response to said electrical signals, a flow director coaxially arranged in said fluid passage and having a plurality of spaced openings cooperatively arranged for directing drilling fluids in selected fluid paths along said fluid passage, an annular signal-producing member coaxially arranged in said fluid passage and having a plurality of alternately distributed angularly spaced openings and obstructions cooperatively arranged to successively cross said fluid paths upon rotation of said signal-producing member for producing cyclic acoustic signals representative of said electrical signals in drilling fluids flowing through said fluid passage; and   torque-responsive means adapted for selectively driving said signal-producing member including a rotatable shaft coaxially disposed in said fluid passage and cooperatively coupled to said motor for rotation thereby, a first transversely oriented coaxial camming surface on said .[.surface.]. .Iadd.signal .Iaddend.producing member having a plurality of first undulations thereon, a second transversely oriented coaxial camming surface on said shaft opposing said first camming surface and having a plurality of second undulations thereon substantially complementary to said first undulations, a plurality of rolling members disposed between said first and second camming surfaces and in rolling engagement therewith, and first biasing means for normally urging said first camming surface toward said second camming surface to rotate said signal-producing member in a transverse plane adjacent to said flow director as long as said rolling members are respectively disposed within opposed valleys of said undulations and for yielding in response to an increase in driving torque required by said signal-producing member to rotate said signal-producing member in a transverse plane more distant from said flow director as said rolling members are respectively disposed between opposed inclines of said undulations to clear fluid-borne debris from between said flow director and said signal-producing member.   
     
     
       19. The apparatus of claim 18 wherein said first biasing means include spring means. 
     
     
       20. The apparatus of claim 18 wherein said first biasing ameans include spring means and pressure-responsive means cooperatively arranged for urging said signal-producing member toward said flow director with a force related to the pressure differential across said signal-producing member. 
     
     
       21. The apparatus of claim 20 wherein said signal-producing member is upstream of said flow director. 
     
     
       22. The apparatus of claim 18 wherein said flow director is cooperatively arranged for movement between longitudinally spaced positions in said fluid passage and further including second biasing means cooperatively arranged for normally urging said flow director toward said signal-producing member and responsive to increased pressure differentials across said .[.signal-producing member.]. .Iadd.flow director .Iaddend.for yieldably shifting said flow director away from said signal-producing member to clear fluid-borne debris from between said flow director and said signal-producing member. 
     
     
       23. The apparatus of claim 22 wherein said second biasing means include spring means. 
     
     
       24. The apparatus of claim 22 wherein said second biasing means include spring means and first pressure-responsive means cooperatively arranged for urging said flow director toward said signal-producing member so long as said signal-producing member is rotating adjacent to said flow director, and second pressure-responsive means cooperatively arranged for urging said flow director away from said signal-producing member whenever said obstructions on said signal-producing member are opposite said openings on said flow director. 
     
     
       25. The apparatus of claim 24 wherein said first biasing means include spring means and pressure-responsive means cooperatively arranged for urging said signal-producing member toward said flow director with a force related to the pressure differential across said signal-producing member. 
     
     
       26. The apparatus of claim 25 further including control means coupled to said motor and responsive to slowing of said flow-obstructing member below said selected speed for alternately rotating said motor back and forth in opposite rotative directions so long as said flow-obstructing member is slowed below said selected speed. 
     
     
       27. The apparatus of claim 26 wherein said signal-producing member is upstream of said flow director.