Rolling annular seal

Abstract

Sealing assemblies with rolling annular seals are provided. In one embodiment, an apparatus includes a stuffing box having a rolling seal positioned in a body for sealing against a tubing or wireline cable received in a bore of the body. The rolling seal can rotate within the body to roll along the tubing or wireline cable in response to movement of the tubing or wireline cable through the body and friction between the rolling seal and the tubing or wireline cable. Additional systems, devices, and methods are also disclosed.

1 . An apparatus comprising:
 a stuffing box including:
 a body with a bore for receiving a tubing or wireline cable; and 
 a rolling seal positioned along the bore to seal against the tubing or wireline cable, 
 wherein the rolling seal is positioned in a seal grove in the body, and wherein the rolling seal rotates within the body so as to roll along the tubing or wireline cable in response to movement of the tubing or wireline cable through the body and to friction between the rolling seal and the tubing or wireline cable, 
   
     
     
         2 . The apparatus of  claim 1 , wherein the body includes first and second body members coupled together, the bore extends through each of the first and second body members, and the seal groove in which the rolling seal is positioned includes a first seal groove portion formed in the first body member and a second seal groove portion formed in the second body member. 
     
     
         3 . The apparatus of  claim 2 , wherein the body includes a third body member coupled together with the first and second body members, the bore extends through the third body member as well as through the first and second body members, the stuffing box includes an additional rolling seal positioned in an additional seal groove in the body along the bore, the additional rolling seal and the body are arranged to allow the additional rolling seal to rotate within the body so as to roll along the tubing or wireline cable in response to movement of the tubing or wireline cable through the body and friction between the additional rolling seal and the tubing or wireline cable, and the additional seal groove in which the additional rolling seal is positioned includes a first additional seal groove portion formed in the first body member and a second additional seal groove portion formed in the third body member. 
     
     
         4 . The apparatus of  claim 2 , wherein the second body member includes a cap fastened to the first body member. 
     
     
         5 . The apparatus of  claim 2 , comprising an additional seal that seals between the first and second body members. 
     
     
         6 . The apparatus of  claim 5 , wherein the additional seal is positioned along a neck of the first body member that is received in a recess of the second body member. 
     
     
         7 . The apparatus of  claim 1 , comprising the tubing, wherein the tubing includes a coiled tubing that is received in the bore of the body and the rolling seal seals against the coiled tubing. 
     
     
         8 . The apparatus of  claim 1 , comprising the wireline cable, wherein the wireline cable includes a wireline or slickline that is received in the bore of the body and the rolling seal seals against the wireline or slickline. 
     
     
         9 . The apparatus of  claim 1 , wherein the stuffing box is installed at a wellhead. 
     
     
         10 . The apparatus of  claim 9 , comprising a wireline valve and a lubricator coupled to the stuffing box. 
     
     
         11 . A method comprising:
 inserting a cable or tubing into a bore of a housing having a toroidal seal such that the toroidal seal seals against the cable or tubing;   moving the cable or tubing through the bore of the housing; and   rolling the toroidal seal along the cable or tubing as the cable or tubing is moved through the bore of the housing such that an inner portion of the toroidal seal abutting the cable or tubing moves tangentially in a same direction as the cable or tubing and an outer portion of the toroidal seal, opposite the inner portion, moves in an opposite direction.   
     
     
         12 . The method of  claim 11 , wherein moving the cable or tubing through the bore of the housing includes both lowering the cable or tubing into a well through the bore of the housing and raising the cable or tubing from the well through the bore of the housing. 
     
     
         13 . The method of  claim 11 , comprising compressing the toroidal seal within the housing to change the inner diameter of the toroidal seal. 
     
     
         14 . The method of  claim 11  comprising lubricating the toroidal seal as it rolls along the cable or tubing.