Rotary bit with jet nozzles
First Claim
1. Rotary bit with cutting elements and a plurality of liquid-discharger nozzles for drilling hole in an underground formation, the bit including a body with a central cavity and a shank attached to the body and enclosing a central fluid passage that communicates with the cavity, a first self-cleaning screening element with a plurality of fluid passages allowing the passage of a predetermined size range of particles carried by a fluid, the element being at least partly mounted in the cavity and dividing the cavity in a first part communicating with a first set of nozzles, and a second part communicating with the central passage of a drill string when the shank of the bit is copuled thereto, said second part being divided in two further parts by a second screening element having a plurality of fluid passages through which coarser particles can pass than through the fluid passages of the first screening element, one of these two further parts communicating with the fluid passages in the first screening element, and the other part communicating with a second set of nozzles that are fewer in number than the first set of nozzles, the fluid passage through each of the nozzles of the second set being larger than the fluid passage through each of the nozzles of the first set and being at least equal to a fluid passage of the second screening element.
1 Assignment
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Accused Products
Abstract
A jet rotary drill bit confirming a first strainer element allowing the passage of mud carrying small-sized particles, but preventing relatively coarse particles from passing to the jet nozzles. The first strainer element is self-cleaning and the relatively coarse particles are passed on to a second strainer on which they remain trapped.
31 Citations
13 Claims
- 1. Rotary bit with cutting elements and a plurality of liquid-discharger nozzles for drilling hole in an underground formation, the bit including a body with a central cavity and a shank attached to the body and enclosing a central fluid passage that communicates with the cavity, a first self-cleaning screening element with a plurality of fluid passages allowing the passage of a predetermined size range of particles carried by a fluid, the element being at least partly mounted in the cavity and dividing the cavity in a first part communicating with a first set of nozzles, and a second part communicating with the central passage of a drill string when the shank of the bit is copuled thereto, said second part being divided in two further parts by a second screening element having a plurality of fluid passages through which coarser particles can pass than through the fluid passages of the first screening element, one of these two further parts communicating with the fluid passages in the first screening element, and the other part communicating with a second set of nozzles that are fewer in number than the first set of nozzles, the fluid passage through each of the nozzles of the second set being larger than the fluid passage through each of the nozzles of the first set and being at least equal to a fluid passage of the second screening element.
Specification
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- Resources
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Current AssigneeShell Oil Company (Shell Plc)
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Original AssigneeShell Oil Company (Shell Plc)
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InventorsFeenstra, Robijn, Walker, Bruce H.
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Primary Examiner(s)Novosad, Stephen J.
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Assistant Examiner(s)Falk, Joseph
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Application NumberUS06/267,957Time in Patent Office425 DaysField of Search175/312, 175/313, 175/339, 175/340, 175/393US Class Current175/339CPC Class CodesE21B 10/18 characterised by conduits o...E21B 10/60 characterised by conduits o...E21B 21/002 Down-hole drilling fluid se...E21B 27/005 Collecting means with a str...
