Packer Assembly with a Standoff

Abstract

An apparatus including a downhole tool for conveyance in a wellbore extending into a subterranean formation. The downhole tool includes a mandrel, and a first packer and a second packer expandable from the mandrel into contact with a wall of the wellbore. The downhole tool includes a standoff coupled to the mandrel between the first packer and the second packer and having a rigid outer perimeter that is diametrically larger than an outer perimeter of the mandrel.

1 . An apparatus, comprising:
 a downhole tool for conveyance in a wellbore extending into a subterranean formation, comprising:
 a mandrel; 
 a first packer and a second packer expandable from the mandrel into contact with a wall of the wellbore; and 
 a standoff coupled to the mandrel between the first packer and the second packer and having a rigid outer perimeter that is diametrically larger than an outer perimeter of the mandrel. 
   
     
     
         2 . The apparatus of  claim 1  wherein the standoff comprises a plurality of first members spanning ones of a plurality of second members. 
     
     
         3 . The apparatus of  claim 2  wherein the plurality of first members and second members forms the rigid outer perimeter. 
     
     
         4 . The apparatus of  claim 1  wherein the plurality of first members is selected from the group consisting of:
 non-circular members; 
 non-concentric members; and 
 webs. 
 
     
     
         5 . The apparatus of  claim 1  wherein the plurality of first members is selected from the group consisting of:
 substantially circular members; 
 substantially concentric ring members; and 
 supporting rings. 
 
     
     
         6 . The apparatus of  claim 1  wherein the standoff comprises:
 a plurality of ring members each substantially coaxially aligned with a longitudinal axis of the mandrel; and 
 a plurality of longitudinal members each extending substantially parallel to the longitudinal axis of the mandrel and coupled to ones of the plurality of ring members. 
 
     
     
         7 . The apparatus of  claim 1  wherein the standoff comprises stainless steel. 
     
     
         8 . The apparatus of  claim 1  wherein the standoff comprises substantially ring-shaped end members at opposing ends coupled to the mandrel. 
     
     
         9 . The apparatus of  claim 1  wherein the standoff comprises a plurality of openings through which wellbore fluid flows. 
     
     
         10 . The apparatus of  claim 1  wherein the rigid outer perimeter is approximately one inch smaller than a diameter of the wellbore. 
     
     
         11 . The apparatus of  claim 1  wherein the mandrel comprises an inlet and the standoff comprises a filter adjacent to the inlet. 
     
     
         12 . The apparatus of  claim 1  wherein the downhole tool is conveyable in the wellbore via wireline or drill pipe. 
     
     
         13 . A method, comprising:
 coupling a standoff to a mandrel of a downhole tool between first and second packers of the downhole tool, wherein the first and second packers are coupled to the mandrel and the standoff has a rigid outer perimeter that is diametrically larger than an outer perimeter of the mandrel; and   conveying the downhole tool in a wellbore extending into a subterranean formation.   
     
     
         14 . The method of  claim 13 , further comprising:
 isolating a portion of the wellbore by expanding the first and second packers into contact with a wall of the wellbore; and   contacting the wall of the wellbore with the standoff by reducing pressure in the isolated portion of the wellbore.   
     
     
         15 . The method of  claim 13  further comprising flowing wellbore fluids through a plurality of openings in the standoff. 
     
     
         16 . The method of  claim 13  further comprising filtering samples collected from the subterranean formation. 
     
     
         17 . A kit employable with a downhole tool conveyable in a wellbore extending into a subterranean formation and having a mandrel, and a first packer and a second packer expandable from the mandrel into contact with the wall of the wellbore, the kit, comprising:
 a standoff couplable to the mandrel between the first packer and the second packer and having a rigid outer perimeter that is diametrically larger than an outer perimeter of the mandrel.   
     
     
         18 . The kit of  claim 17  wherein the standoff comprises a fastener to mate first and second sections of the standoff about the mandrel. 
     
     
         19 . The kit of  claim 17  wherein the standoff comprises a plurality of first members spanning ones of a plurality of second members. 
     
     
         20 . The kit of  claim 17  wherein the standoff comprises a plurality of openings through which wellbore fluid flows.