Retrievable frac packer

Abstract

A retrievable frac packer is provided which allows frac operations to be conducted with a single, retrievable tool, with the capability of providing positive zone production indications during production testing.

1 . A selectively settable and retrievable frac packer for use inside an annular tube having an inner surface, comprising 
 an annular body comprising a selectively settable and releasable circumferential seal,    a selectively settable and releasable latch, wherein said latch has a latched position which restrains said circumferential seal in sealing engagement with the inner surface of the annular tube and an unlatched position which releases said seal, and    a first valve which selectively controls fluid flow through the annulus of said annular body.    
   
   
       2 . The frac packer of  claim 1 , wherein said latch is wireline settable.  
   
   
       3 . The frac packer of  claim 1 , wherein said latch is hydraulically settable.  
   
   
       4 . The frac packer of  claim 1 , wherein said latch is settable by tubing-conveyed means.  
   
   
       5 . The frac packer of  claim 1 , wherein said latch is mechanically settable.  
   
   
       6 . The frac packer of  claim 1 , wherein said latch is settable by a combination of hydraulic and mechanical action.  
   
   
       7 . The frac packer of  claim 1 , additionally comprising selectively settable and releasable frictional contact between said annular body and the inner surface of the annular tube.  
   
   
       8 . The frac packer of  claim 7 , wherein said frictional contact comprises a slip.  
   
   
       9 . The frac packer of  claim 7 , wherein the position of said latch additionally controls the position of said frictional contact.  
   
   
       10 . The frac packer of  claim 1 , additionally comprising a mechanical bias device to assist in releasing said circumferential seal when said latch is moved from its latched position to its unlatched position.  
   
   
       11 . The frac packer of  claim 7 , additionally comprising a mechanical bias device to assist in releasing said circumferential seal and said frictional contact when said latch is moved from its latched position to its unlatched position.  
   
   
       12 . The frac packer of  claim 10 , wherein said mechanical bias device is a spring.  
   
   
       13 . The frac packer of  claim 11 , wherein said mechanical bias device is a spring.  
   
   
       14 . The frac packer of  claim 1 , additionally comprising a second valve which selectively controls fluid flow through the annulus of said annular body.  
   
   
       15 . The frac packer of  claim 1 , additionally comprising a selectively releasable flagging media within the annulus of said annular body.  
   
   
       16 . The frac packer of  claim 1 , additionally comprising a connector capable of selectively engaging a second frac packer for simultaneous retrieval of both said frac packer and said second frac packer.  
   
   
       17 . A method of using a frac packer in a wellbore, comprising 
 lowering said frac packer to the desired depth,    selectively setting seals on said frac packer to isolate the wellbore above said frac packer from the wellbore below said frac packer,    selectively controlling fluid flow through said frac packer,    selectively releasing said seals, and    retrieving said frac packer from the wellbore.    
   
   
       18 . The method of  claim 17 , additionally comprising the step of selectively allowing flow in one direction through said frac packer.  
   
   
       19 . The method of  claim 17 , wherein the step of retrieving said frac packer additionally comprises the step of retrieving a second frac packer from the wellbore on the same tool string.  
   
   
       20 . The method of  claim 17 , wherein the step of retrieving said frac packer additionally comprises the step of retrieving multiple additional frac packers from the wellbore on the same tool string.  
   
   
       21 . The method of  claim 17 , additionally comprising the step of selectively releasing a flagging media from said frac packer.