Packer end ring with device for gripping base pipe

Abstract

A packer can include an end ring positioned proximate a seal element on a base pipe, and a gripping device which is compressed radially inward by a surface formed in the end ring, the surface encircling the base pipe. A method of constructing a packer can include positioning an end ring on a base pipe proximate a seal element, and radially compressing a gripping device in the end ring, so that the gripping device grips the base pipe, radial compression of the gripping device resulting from longitudinal displacement of the gripping device relative to the end ring.

What is claimed is: 
     
         1 . A packer, comprising:
 an end ring positioned proximate a seal element on a base pipe; and   a circular gripping device which encircles the base pipe and is compressed radially inward by a surface formed in the end ring.   
     
     
         2 . The packer of  claim 1 , wherein the surface comprises a frusto-conical surface. 
     
     
         3 . The packer of  claim 1 , wherein the gripping device grips the base pipe in response to longitudinal displacement of the gripping device relative to the surface. 
     
     
         4 . The packer of  claim 1 , wherein the seal element comprises a swellable material which swells in response to contact with a fluid. 
     
     
         5 . The packer of  claim 1 , wherein the gripping device closes off a gap formed radially between the base pipe and the end ring. 
     
     
         6 . The packer of  claim 1 , wherein the gripping device comprises a circular segment having a split therein which permits radial compression of the circular segment. 
     
     
         7 . The packer of  claim 1 , wherein the gripping device comprises multiple circular segments. 
     
     
         8 . The packer of  claim 1 , further comprising a gripping surface formed on the gripping device. 
     
     
         9 . The packer of  claim 1 , further comprising at least one member which threads into the end ring and thereby radially compresses the gripping device. 
     
     
         10 . The packer of  claim 1 , wherein the gripping device comprises a surface which cooperatively engages the end ring surface, and wherein at least one of the gripping device and end ring surfaces is provided with a friction reducing material. 
     
     
         11 . A method of constructing a packer, the method comprising:
 positioning an end ring on a base pipe proximate a seal element; and   radially compressing a gripping device in the end ring, so that the gripping device grips the base pipe, radial compression of the gripping device resulting from longitudinal displacement of the gripping device relative to the end ring.   
     
     
         12 . The method of  claim 11 , further comprising the seal element swelling in response to contact with a fluid in a well. 
     
     
         13 . The method of  claim 11 , further comprising the gripping device closing off a gap formed radially between the base pipe and the end ring. 
     
     
         14 . The method of  claim 11 , wherein the gripping device comprises a circular segment having a split therein which permits radial compression of the circular segment. 
     
     
         15 . The method of  claim 11 , wherein the gripping device comprises multiple circular segments. 
     
     
         16 . The method of  claim 11 , wherein a gripping surface is formed on the gripping device, and wherein the radially compressing comprises engaging the gripping surface with the base pipe. 
     
     
         17 . The method of  claim 11 , wherein the radially compressing further comprises threading at least one member into the end ring, thereby radially compressing the gripping device. 
     
     
         18 . The method of  claim 11 , wherein the radially compressing further comprises the gripping device being compressed radially inward by a surface formed in the end ring, the surface encircling the base pipe. 
     
     
         19 . The method of  claim 18 , wherein the surface comprises a frusto-conical surface. 
     
     
         20 . The method of  claim 18 , wherein the gripping device comprises a surface which cooperatively engages the end ring surface, and wherein at least one of the gripping device and end ring surfaces is provided with a friction reducing material. 
     
     
         21 . A packer, comprising:
 an end ring positioned proximate a seal element on a base pipe; and   a gripping device which is compressed radially inward by a surface formed in the end ring, the surface encircling the base pipe.   
     
     
         22 . The packer of  claim 21 , wherein the surface comprises a frusto-conical surface. 
     
     
         23 . The packer of  claim 21 , wherein the gripping device grips the base pipe in response to longitudinal displacement of the gripping device relative to the surface. 
     
     
         24 . The packer of  claim 21 , wherein the seal element comprises a swellable material which swells in response to contact with a fluid. 
     
     
         25 . The packer of  claim 21 , wherein the gripping device closes off a gap formed radially between the base pipe and the end ring. 
     
     
         26 . The packer of  claim 21 , wherein the gripping device comprises a circular segment having a split therein which permits radial compression of the circular segment. 
     
     
         27 . The packer of  claim 21 , wherein the gripping device comprises multiple circular segments. 
     
     
         28 . The packer of  claim 21 , further comprising a gripping surface formed on the gripping device. 
     
     
         29 . The packer of  claim 21 , further comprising at least one member which threads into the end ring and thereby radially compresses the gripping device. 
     
     
         30 . The packer of  claim 21 , wherein the gripping device comprises a surface which cooperatively engages the end ring surface, and wherein at least one of the gripping device and end ring surfaces is provided with a friction reducing material.