Rotary pulser with flow bypass elements

Abstract

A rotary pulser is described that includes a shroud assembly, a stator supported by the shroud assembly. The stator has an uphole end, a downhole end spaced from the uphole end, and at least one passage that extends from the uphole end to the downhole end. The rotary pulser includes a rotatable element adjacent to the downhole end of the stator and rotatable to selectively obstruct the at least one passage to generate a pressure pulse in the fluid when the fluid passes through the rotary pulser. The rotary pulser also includes one or more bypass elements that are configured to permit fluid to bypass the stator and the rotatable element when a fluid passes through the drill string and the rotary pulser.

What is claimed is: 
     
         1 . A rotary pulser configured to be positioned along a drill string through which a fluid flows, the rotary pulser comprising:
 a shroud assembly configured to be supported in an internal passage of the drill string;   a stator supported by the shroud assembly, the stator including an uphole end, a downhole end spaced from the uphole end, and at least one passage that extends from the uphole end to the downhole end;   a rotatable element adjacent to the downhole end of the stator and rotatable to selectively obstruct the at least one passage to generate a pressure pulse in the fluid when the fluid passes through the rotary pulser; and   one or more bypass elements located along an outer region of the shroud assembly, wherein the one or more fluid bypass elements are configured to permit fluid to bypass the stator and the rotatable element when a fluid passes through the drill string and the rotary pulser.   
     
     
         2 . The rotary pulser according to  claim 1 , wherein the shroud assembly has a first housing configured to support the stator and a second housing coupled to the first housing, wherein the second housing defines the one or more fluid channels. 
     
     
         3 . The rotary pulser according to  claim 1 , wherein the one or more fluid bypass element are one or more fluid channels. 
     
     
         4 . The rotary pulser according to  claim 1 , wherein the one or more fluid channels is a set of fluid channels, wherein the set of channels are positioned circumferentially around the shroud assembly. 
     
     
         5 . The rotary pulser according to  claim 1 , wherein the one or more fluid channels have an uphole end and a downhole end spaced from the uphole end along a passage axis, wherein the uphole end of the one or more fluid channels is downhole from the downhole end of the stator. 
     
     
         6 . The rotary pulser according to  claim 1 , wherein the one or more fluid channels includes a nozzle located a downhole end of the one or more fluid channels. 
     
     
         7 . The rotary pulser according to  claim 1 , further comprising a motor assembly coupled to the rotatable element, wherein the motor assembly is operable to rotate the rotatable element relative to the stator through a rotation cycle to generate a pressure pulse. 
     
     
         8 . A rotary pulser configured to be positioned along a drill string through which a fluid flows, the rotary pulser comprising:
 a shroud assembly configured to be supported in an internal passage of the drill string;   a stator supported by the shroud assembly, the stator including an uphole end, a downhole end spaced from the uphole end, and at least one passage that extends from the uphole end to the downhole end;   a rotatable element adjacent to the downhole end of the stator and rotatable to selectively obstruct the at least one passage;   a motor assembly coupled to the rotatable element, wherein the motor assembly is operable to rotate the rotatable element relative to the stator through a rotation cycle to generate a pressure pulse; and   one or more fluid bypass elements located along an outer region of the shroud assembly, wherein the one or more fluid bypass elements are configured to permit fluid to bypass the stator and the rotatable element when a fluid passes through the drill string and rotary pulser.   
     
     
         9 . The rotary pulser according to  claim 8 , wherein the shroud assembly has first housing configured to support the stator, and a second housing coupled to the first housing, wherein the second housing defines the one or more fluid channels. 
     
     
         10 . The rotary pulser according to  claim 8 , wherein the one or more fluid bypass elements are one or more fluid channels. 
     
     
         11 . The rotary pulser according to  claim 8 , wherein the one or more fluid bypass elements is a set of fluid bypass elements positioned circumferentially about a longitudinal axis. 
     
     
         12 . The rotary pulser according to  claim 8 , wherein the one or more fluid bypass elements have an uphole end and a downhole end spaced from the uphole end along a passage axis, wherein the uphole end of the one or more fluid bypass elements is downhole from the downhole end of the stator. 
     
     
         13 . The rotary pulser according to  claim 8 , wherein the one or more fluid bypass elements includes a nozzle located a downhole end of the one or more fluid bypass elements. 
     
     
         14 . A drilling system, comprising:
 drill string pipes connected end-to-end to form a drill string having an internal passage through which a fluid flows;   a rotary pulser carried by the drill string in the internal passage, the rotary pulser having a shroud assembly, a stator supported by the shroud assembly, at least one passage that extends from an uphole end of the stator to a downhole end of the stator, a rotatable element adjacent to the downhole end of the stator and rotatable to selectively obstruct the at least one passage, and one or more fluid bypass elements located along an outer region of the shroud assembly, wherein the one or more fluid bypass elements are configured to permit fluid to bypass the stator and the rotatable element when a fluid passes through the drill string and rotary pulser; and   a motor assembly coupled to the rotatable element, wherein the motor assembly is operable to rotate the rotatable element relative to the stator through a rotation cycle to generate a pressure pulse.   
     
     
         15 . The drilling system according to  claim 14 , wherein the shroud assembly has first housing configured to support the stator, and a second housing coupled to the first housing, wherein the second housing defines the one or more fluid channels. 
     
     
         16 . The drilling system according to  claim 14 , wherein the one or more fluid bypass elements are one or more fluid channels. 
     
     
         17 . The drilling system according to  claim 14 , wherein the one or more fluid bypass elements is a set of fluid bypass elements positioned circumferentially about a longitudinal axis. 
     
     
         18 . The drilling system according to  claim 14 , wherein the one or more fluid channels have an uphole end and a downhole end spaced from the uphole end along a passage axis, wherein the uphole end of the one or more fluid channels is downhole from the downhole end of the stator. 
     
     
         19 . A method of transmitting information from a downhole location along a drill string forming a well bore in an earthen formation toward a surface of the earthen formation, the method comprising:
 directing a drilling fluid through an elongated passage of the drill string toward a rotary pulser mounted to the drill string in the elongated passage, the rotary pulser including a stator that includes at least one passage, and a rotatable element adjacent to a downhole end of the stator;   while a first portion of the drilling fluid passes through the rotary pulser, rotating the rotatable element from a first position, where the rotatable element permits the drilling fluid to pass through the at least one passage, to a second position, where the rotatable obstructs the drilling fluid through the at least one passage, thereby generating a pressure pulse in drilling fluid; and   causing a portion of the drilling fluid to bypass the rotary pulser through one or more fluid channels located externally relative to the rotary pulser.   
     
     
         20 . The method according to  claim 19 , wherein the one or more fluid bypass elements cause the drilling fluid to bypass the rotary pulser. 
     
     
         21 . The method according to  claim 19 , wherein the one or more fluid bypass elements are one or more fluid channels. 
     
     
         22 . The method according to  claim 19 , wherein the one or more fluid bypass elements is a set of fluid bypass elements positioned circumferentially about a longitudinal axis. 
     
     
         23 . The method according to  claim 19 , wherein the one or more fluid channels have an uphole end and a downhole end spaced from the uphole end along a passage axis, wherein the uphole end of the one or more fluid channels is downhole from the downhole end of the stator.