Casing conveyed, externally mounted perforation concept

Abstract

Provided is an untethered downhole tool assembly. The untethered downhole tool assembly, in one aspect, includes a housing and a signal generator located on or in the housing, the signal generator capable of transmitting a passive or active signal to a downhole device located on an outside of a metal wellbore casing as it travels through an inside of the metal wellbore casing.

What is claimed is: 
     
         1 . An untethered downhole tool assembly, comprising:
 a housing; and   a signal generator located on or in the housing, the signal generator capable of transmitting a passive or active signal to a downhole device located on an outside of a metal wellbore casing as it travels through an inside of the metal wellbore casing.   
     
     
         2 . The untethered downhole tool assembly as recited in  claim 1 , wherein the signal generator is capable of transmitting a passive magnetic signal, passive acoustic signal, passive vibration signal, or a passive radiation signal through the metal wellbore casing. 
     
     
         3 . The untethered downhole tool assembly as recited in  claim 1 , further including a power source located within the housing, and further wherein the signal generator is a powered transmitter capable of transmitting an active wireless signal through the metal wellbore casing. 
     
     
         4 . The untethered downhole tool assembly as recited in  claim 3 , wherein the powered transmitter is adapted to embed instructions for the downhole device on the active wireless signal. 
     
     
         5 . The untethered downhole tool assembly as recited in  claim 1 , further including a radially deployable packer element coupled to the housing, the radially deployable packer element movable from a radially retracted state to a radially deployed state. 
     
     
         6 . The untethered downhole tool assembly as recited in  claim 5 , wherein the radially deployable packer element is movable from the radially retracted state to the radially deployed state upon receiving one or more signals from the downhole device located on the outside of the metal wellbore casing. 
     
     
         7 . The untethered downhole tool assembly as recited in  claim 1 , further including one or more slip elements coupled to the housing. 
     
     
         8 . The untethered downhole tool assembly as recited in  claim 1 , wherein the housing includes one or more fluid paths extending along an entire length (l 2 ) thereof. 
     
     
         9 . The untethered downhole tool assembly as recited in  claim 8 , further including a valve assembly positioned within the housing and across at least one of the one or more fluid paths for closing the one or more fluid paths. 
     
     
         10 . The untethered downhole tool assembly as recited in  claim 1 , wherein the housing comprises a dissolvable or degradable material. 
     
     
         11 . A method for operating a well system, comprising:
 positioning a downhole device in a subterranean formation along an outer surface of a metal wellbore casing;   deploying an untethered downhole tool assembly downhole within an inside of the metal wellbore casing, the untethered downhole tool assembly including;
 a housing; and 
 a signal generator located on or in the housing; and 
   transmitting a passive or active signal to the downhole device located along the outer surface of the metal wellbore casing using the signal generator, as the untethered downhole tool assembly approaches the downhole device.   
     
     
         12 . The method as recited in  claim 11 , wherein transmitting a passive or active signal includes transmitting a passive magnetic signal, passive acoustic signal, passive vibration signal, or a passive radiation signal through the metal wellbore casing. 
     
     
         13 . The method as recited in  claim 11 , further including a power source located within the housing, and further wherein transmitting a passive or active signal includes transmitting an active wireless signal through the metal wellbore casing. 
     
     
         14 . The method as recited in  claim 13 , wherein the active wireless signal has instructions for the downhole device embedded therein. 
     
     
         15 . The method as recited in  claim 14 , wherein the downhole device is a downhole perforating device, and further wherein the instructions are triggering instructions. 
     
     
         16 . The method as recited in  claim 11 , further including a radially deployable packer element coupled to the housing, and further including moving the radially deployable packer element from a radially retracted state to a radially deployed state upon receiving one or more signals from the downhole device located on the outside of the wellbore casing. 
     
     
         17 . The method as recited in  claim 11 , wherein the untethered downhole tool assembly further includes one or more slip elements coupled to the housing. 
     
     
         18 . The method as recited in  claim 11 , wherein the housing of the untethered downhole tool assembly includes one or more fluid paths extending along an entire length (l 2 ) thereof. 
     
     
         19 . The method as recited in  claim 18 , further including a valve assembly positioned within the housing and across at least one of the one or more fluid paths for closing the one or more fluid paths. 
     
     
         20 . The method as recited in  claim 11 , wherein the housing comprises a dissolvable or degradable material, and further including dissolving or degrading the housing after transmitting the passive or active signal to the downhole device located along the outer surface of the metal wellbore casing.