Downhole pressure sensing device for open-hole operations

Abstract

A drilling assembly is provided that includes a drillpipe, a drill bit provided at a downhole end of the drillpipe, and a pressure control module positioned proximate to the drill bit, the pressure control module including a pressure sensor that detects pressure conditions at the drill bit and automatically shut-off fluid flow within the drillpipe upon detecting a threshold pressure condition. A processor is provided at the pressure control module that communicates with a computer-readable storage medium having instructions stored thereon, to perform the operations of detecting pressure conditions at the drill bit, automatically shutting-off fluid flow within the drillpipe upon detecting a threshold pressure condition, and switching-on fluid flow within the drillpipe upon detecting an activation pressure condition.

What is claimed is: 
     
         1 . A drilling assembly, comprising:
 a pressure control module positioned proximate to a drill bit, the pressure control module comprising:   a pressure sensor that detects pressure conditions at the drill bit; and   a valve that automatically shuts-off fluid flow within a drillpipe based on the pressure sensor detecting threshold pressure condition.   
     
     
         2 . The drill assembly of  claim 1 , further comprising:
 a drillpipe having the drill bit provided at a downhole end, the drillpipe including one of a drill string or coil tubing.   
     
     
         3 . The drill assembly of  claim 1 , wherein the pressure sensor detects pressure conditions associated with a drilling fluid hydrostatic pressure and a formation hydrostatic pressure. 
     
     
         4 . The drill assembly of  claim 2 , wherein the valve automatically shuts-off fluid flow within the drillpipe when the formation hydrostatic pressure exceeds the drilling fluid hydrostatic pressure. 
     
     
         5 . The drill assembly of  claim 2 , wherein the valve switches-on fluid flow within the drillpipe when the pressure sensor detects an activation condition. 
     
     
         6 . The drill assembly of  claim 5 , wherein the activation condition includes at least one of a preselected pressure for a preselected amount of time and lapsing of a preselected amount of time. 
     
     
         7 . The drill assembly of  claim 2 , further comprising a second pressure control module positioned along the drillpipe, the second pressure control module comprising:
 a second pressure sensor that detects pressure conditions along the drillpipe; and   a second valve that automatically shuts-off fluid flow within the drillpipe when the second pressure sensor detects a second threshold pressure condition.   
     
     
         8 . A method of performing open-hole drilling operations, the method comprising:
 detecting pressure conditions at a drill bit provided at a downhole end of a drillpipe;   automatically shutting-off fluid flow within the drillpipe upon detecting a threshold pressure condition; and   switching-on fluid flow within the drillpipe upon detecting an activation condition.   
     
     
         9 . The method of  claim 8 , wherein detecting the pressure conditions includes detecting a drilling fluid hydrostatic pressure and detecting a formation hydrostatic pressure. 
     
     
         10 . The method of  claim 9 , wherein automatically shutting-off fluid flow within the drillpipe is performed when the formation hydrostatic pressure exceeds the drilling fluid hydrostatic pressure. 
     
     
         11 . The method of  claim 8 , wherein the activation condition includes at least one of a preselected pressure for a preselected amount of time and lapsing of a preselected amount of time. 
     
     
         12 . The method of  claim 11 , wherein the preselected pressure for the preselected amount of time is actuated from a remote location. 
     
     
         13 . The method of  claim 8 , wherein the activation condition includes detecting a drilling fluid hydrostatic pressure. 
     
     
         14 . A drilling assembly, comprising:
 a drillpipe;   a drill bit provided at a downhole end of the drillpipe;   a pressure control module positioned proximate to the drill bit; and   a processor provided at the pressure control module, the processor communicating with a computer-readable storage medium having instructions stored thereon that, when executed by the processor, cause the processor to:   detect pressure conditions at the drill bit;   automatically shut-off fluid flow within the drillpipe upon detecting a threshold pressure condition; and   switch-on fluid flow within the drillpipe upon detecting an activation condition.   
     
     
         15 . The drilling assembly of  claim 14 , wherein the drillpipe includes one of a drill string or coil tubing. 
     
     
         16 . The drilling assembly of  claim 14 , wherein the processor is further configured to obtain a signal from a pressure sensor that detects the pressure conditions including a drilling fluid hydrostatic pressure and a formation hydrostatic pressure. 
     
     
         17 . The drilling assembly of  claim 14 , further comprising an alternator that provides electrical energy to the processor. 
     
     
         18 . The drilling assembly of  claim 14 , wherein the activation condition includes at least one of a preselected pressure for a preselected amount of time and lapse of a preselected amount of time. 
     
     
         19 . The drilling assembly of  claim 18 , wherein the preselected pressure for the preselected amount of time is actuated from a remote location. 
     
     
         20 . The drilling assembly of  claim 14 , further comprising:
 a second pressure control module positioned along the drillpipe; and   a second processor provided at the second pressure control module, the second processor communicating with a computer-readable storage medium having instructions stored thereon that, when executed by the second processor, cause the second processor to:   detect pressure conditions along the drillpipe;   automatically shut-off fluid flow within the drillpipe upon detecting a second threshold pressure condition; and   switch-on fluid flow within the drillpipe upon detecting a second activation condition.