Plug slip ring with retaining mechanism and method

Abstract

A downhole tool for sealing a well includes a push ring; a first slip ring located adjacent to the push ring; a first wedge located adjacent to the first slip ring and configured to push the first slip ring and separate the first slip ring into parts; and a retaining mechanism configured to retain the first slip ring next to one of the push ring or the first wedge. The retaining mechanism is part of either (1) the first slip ring or (2) the one of the push ring or the first wedge, but not both.

What is claimed is: 
     
         1 . A downhole tool for sealing a well, the downhole tool comprising:
 a push ring;   a first slip ring located adjacent to the push ring;   a first wedge located adjacent to the first slip ring and configured to push the first slip ring and separate the first slip ring into parts; and   a retaining mechanism configured to retain the first slip ring next to one of the push ring or the first wedge,   wherein the retaining mechanism is part of either (1) the first slip ring or (2) the one of the push ring or the first wedge, but not both.   
     
     
         2 . The downhole tool of  claim 1 , wherein the retaining mechanism is part of the push ring. 
     
     
         3 . The downhole tool of  claim 1 , wherein the retaining mechanism is part of the first wedge. 
     
     
         4 . The downhole tool of  claim 1 , wherein the retaining mechanism is part of the first wedge and the retaining mechanism is located under the first slip ring. 
     
     
         5 . The downhole tool of  claim 1 , wherein the retaining mechanism is independent and located at an interface between the first wedge and the first slip ring. 
     
     
         6 . The downhole tool of  claim 1 , wherein the retaining mechanism is part of the push ring and there is an additional retaining mechanism that is part of the wedge. 
     
     
         7 . The downhole tool of  claim 1 , wherein the slip ring has a first number “n” of slip ring parts and the retaining mechanism has a number “m” of parts, and m is smaller than n. 
     
     
         8 . The downhole tool of  claim 1 , wherein the slip ring has a first number “n” of slip ring parts and the retaining mechanism has a number “m” of parts, and m is equal to n. 
     
     
         9 . The downhole tool of  claim 1 , wherein the slip ring is made as a single, integral piece. 
     
     
         10 . The downhole tool of  claim 1 , wherein the slip ring is made of plural individual elements that are hold together by the retaining mechanism. 
     
     
         11 . The downhole tool of  claim 1 , wherein the retaining mechanism has a first part located on the first wedge and a second part located on the first slip ring. 
     
     
         12 . The downhole tool of  claim 11 , wherein the first part engages the second part in a locking configuration. 
     
     
         13 . The downhole tool of  claim 11 , wherein the first part is a tongue and the second part is a groove. 
     
     
         14 . The downhole tool of  claim 1 , further comprising:
 a breaking mechanism located next to the retaining mechanism, and configured to break the retaining mechanism when the downhole tool is set,   wherein the retaining mechanism is attached to the first slip ring and configured to keep parts of the first slip ring together.   
     
     
         15 . The downhole tool of  claim 1 , further comprising:
 a sealing element for sealing the well and located adjacent to the first wedge;   a second wedge located adjacent to the sealing element;   a second slip ring located adjacent to the second wedge; and   a mule shoe located adjacent to the second slip ring.   
     
     
         16 . A downhole tool for sealing a well, the downhole tool comprising:
 a mule shoe;   a first slip ring located adjacent to the mule shoe;   a first wedge located adjacent to the first slip ring and configured to push the first slip ring and separate the first slip ring into parts; and   a retaining mechanism configured to retain the first slip ring next to one of the first wedge and the mule shoe,   wherein the retaining mechanism is part of either ( 1 ) the first slip ring or ( 2 ) one of the first wedge and the mule shoe, but not both.   
     
     
         17 . The downhole tool of  claim 16 , wherein the retaining mechanism is part of the mule show. 
     
     
         18 . The downhole tool of  claim 16 , wherein the retaining mechanism is part of the first wedge. 
     
     
         19 . The downhole tool of  claim 16 , wherein the retaining mechanism is part of the first wedge and the retaining mechanism is located under the first slip ring. 
     
     
         20 . The downhole tool of  claim 16 , wherein the retaining mechanism is independent and located at an interface between the first wedge and the first slip ring. 
     
     
         21 . The downhole tool of  claim 16 , wherein the retaining mechanism is part of the mule shoe and there is an additional retaining mechanism that is part of the first wedge. 
     
     
         22 . The downhole tool of  claim 16 , further comprising:
 a breaking mechanism located adjacent to the retaining mechanism and configured to break the retaining mechanism when the downhole tool is set,   wherein the retaining mechanism is attached to the first slip ring and configured to keep parts of the first slip ring together.   
     
     
         23 . The downhole tool of  claim 16 , further comprising:
 a push ring;   a second slip ring located adjacent to the push ring;   a second wedge located adjacent to the second slip ring and configured to push the second slip ring; and   a sealing element for sealing the well and located between the first wedge and the second wedge.   
     
     
         24 . The downhole tool of  claim 23 , wherein the first and second wedges are configured to squeeze the sealing element to extend radially and each of the first and second wedges are configured to break the first and second slip rings, respectively. 
     
     
         25 . The downhole tool of  claim 16 , wherein the mule shoe, the first slip ring, and the first wedge are located on this order on a mandrel. 
     
     
         26 . The downhole tool of  claim 16 , wherein the slip ring is made as a single, integral piece. 
     
     
         27 . The downhole tool of  claim 16 , wherein the slip ring is made of plural individual elements that are hold together by the retaining mechanism. 
     
     
         28 . A downhole tool for sealing a well, the downhole tool comprising:
 a push ring;   a first slip ring located adjacent to the push ring;   a first wedge located adjacent to the first slip ring and configured to push the first slip ring;   a sealing element for sealing the well and located adjacent to the first wedge;   a second wedge located adjacent to the sealing element;   a second slip ring located adjacent to the second wedge;   a mule shoe located adjacent to the second slip ring; and   a retaining mechanism configured to connect at least one of the first slip ring and the second slip ring to one of the push ring, the first wedge, the second wedge and the mule shoe,   wherein the retaining mechanism is part of either (1) the first slip ring or the second slip ring, or (2) one of the push ring, the first wedge, the second wedge or the mule shoe, but not both.   
     
     
         29 . A downhole tool for sealing a well, the downhole tool comprising:
 a slip ring located on a mandrel;   a wedge located adjacent to the slip ring;   a retaining mechanism located adjacent to the slip ring and configured to maintain the slip ring attached to the mandrel; and   an element located adjacent to the retaining mechanism,   wherein the retaining mechanism is independent of the slip ring, the wedge and the element.   
     
     
         30 . The downhole of  claim 29 , wherein the retaining mechanism is a cage extending all around the mandrel. 
     
     
         31 . The downhole of  claim 29 , wherein the retaining mechanism includes a cage, a shear tab for each independent part of the slip ring, the shear tab being attached to the cage. 
     
     
         32 . The downhole of  claim 31 , further comprising:
 a shear band located between the slip ring and the wedge.   
     
     
         33 . The downhole of  claim 32 , wherein the shear band has a first portion that enters a groove of the slip ring and a second portion that enters a groove of the wedge. 
     
     
         34 . The downhole of  claim 33 , wherein the shear band and the shear tab break to release the independent part. 
     
     
         35 . A method for using a plug in a well, the method comprising:
 providing the plug with a retaining mechanism located between a slip ring and one of a wedge, mule shoe and push ring;   lowering the plug into the well;   setting the plug into the well by activating a setting tool, which results in parts of the slip ring to move away from each other,   wherein the retaining mechanism is configured to guide the parts of the slip ring to maintain a substantially uniform gap between the parts.