Downhole tool with radial array of conformable sensors for downhole detection and imaging

Abstract

According to aspects of the present disclosure, an example downhole tool may include tool body, a first pad radially extendable from the tool body, and a radial array of conformable sensors coupled to the first pad. At least one conformable sensor of the radial array of conformable sensors may include a first flexible material. A transmitter may be coupled to one of the tool body and the first flexible material, and a receiver may be coupled to one of the tool body and the first flexible material. At least one of the transmitter and the receiver may be coupled to the first flexible material.

What is claimed is: 
     
         1 . A downhole tool, comprising
 a tool body;   a first pad radially extendable from the tool body;   a radial array of conformable sensors coupled to the first pad, wherein at least one conformable sensor of the radial array of conformable sensors comprises a first flexible material;   a transmitter coupled to one of the tool body and the first flexible material; and   a receiver coupled to one of the tool body and the first flexible material;   wherein at least one of the transmitter and the receiver is coupled to the first flexible material.   
     
     
         2 . The downhole tool of  claim 1 , wherein both the transmitter and the receiver are coupled to the first flexible material; and
 the receiver comprises at least two windings with different orientations.   
     
     
         3 . The downhole tool of  claim 1 , further comprising
 a second pad extendable from the tool body; and   an azimuthal array of conformable sensors coupled to the second pad.   
     
     
         4 . The downhole tool of one of  claims 3 , wherein the second pad is coupled to the first pad. 
     
     
         5 . The downhole tool of  claim 3 , wherein the azimuthal array of conformable sensors comprises a second conformable sensor that includes
 a second flexible material;   a second transmitter coupled to the second flexible material; and   a second receiver coupled to the second flexible material.   
     
     
         6 . The downhole tool of  claim 1 , further comprising a control unit comprising a processor and a memory device coupled to the processor, the memory device containing a set of instructions that, when executed by the processor, cause the processor to:
 select a first combination of conformable sensors to generate a current response measurement with a first depth of investigation; and   select a second combination of conformable sensors to generate a current response measurement with a second depth of investigation.   
     
     
         7 . The downhole tool of  claim 6 , wherein the first combination of sensors comprises at least one of
 two conformable sensors of the azimuthal array of sensors,   two conformable sensors of the radial array of sensors; and   one conformable sensor of the azimuthal array of conformable sensors and one conformable sensor of the radial array of conformable sensors.   
     
     
         8 . The downhole tool of  claim 6 , wherein the first depth of investigation is larger than the second depth of investigation. 
     
     
         9 . The downhole tool of  claim 8 , wherein the set of instructions further causes the processor to determine a parameter of a downhole element remote from radial array of conformable sensors and the azimuthal array of conformable sensors based, at least in part, on at least one of the current response measurement with the first depth of investigation and the current response measurement with the second depth of investigation. 
     
     
         10 . A method for downhole surveying or measuring, comprising
 positioning a downhole tool with a radial array of conformable sensors at least partially within a borehole in a subterranean formation;   generating a first measurement with a first depth of investigation using a first combination of conformable sensors in the radial array of conformable sensors; and   generating a second measurement with a second depth of investigation using a second combination of sensors in the radial array of conformable sensors.   
     
     
         11 . The method of  claim 10 , wherein the radial array of conformable sensors is coupled to a first pad extendable from the downhole tool. 
     
     
         12 . The method of one of  claims 11 , wherein positioning the downhole tool with the radial array of conformable sensors at least partially within the borehole comprises positioning the downhole tool with the radial array of conformable sensors and an azimuthal array of conformable sensors within the borehole. 
     
     
         13 . The method of  claim 13 , wherein the azimuthal array of conformable sensors is coupled to a second pad coupled to the first pad. 
     
     
         14 . The method of  claim 13 , further comprising generating a third measurement with a third depth of investigation using a third combination of conformable sensors in the radial and azimuthal arrays of conformable sensors. 
     
     
         15 . The method of  claim 10 , wherein the first and second measurements correspond to current responses of at least one downhole element within the borehole to an electromagnetic signal generated by the conformable sensors. 
     
     
         16 . The method of  claim 15 , further comprising determining a parameter for a downhole element based, at least in part, on at least one of the first and second measurements. 
     
     
         17 . The method of  claim 16 , further comprising generating a first visualization of the downhole element based, at least in part, on the determined parameter. 
     
     
         18 . The method of  claim 17 , wherein downhole element comprises one of a casing, a cement layer outside of the casing, a wall of the borehole, and the subterranean formation. 
     
     
         19 . The method of  claim 18 , wherein the casing comprises a casing remote from the radial and azimuthal arrays of conformable sensors. 
     
     
         20 . The method of  claim 16 , further comprising determining a parameter for another downhole element based, at least in part, on at least one of the first and second measurements wherein the downhole element comprises a casing and the other downhole element comprises another casing concentric with and outside of the casing.