Non-backed-up packing element system

Abstract

Well tool packing element systems that do not require a back-up element or component include a mandrel, an upper supporting member, a lower supporting member, a cantilever element, and a ramp element disposed on the mandrel. The cantilever element and ramp element are disposed on the mandrel with an interface angle between the cantilever element and the ramp element, the interface angle being less than 90 degrees, preferably in a range from 40 degrees to 60 degrees, and more preferably at an angle greater than 45 degrees. When an axial load is applied to upper and lower supporting members, cantilever element and ramp element are forced outward and into an inner wall surface of a casing to seal off the casing bore.

1 . A packing element system for a well tool comprising:
 a mandrel;   rigid upper and lower supporting members disposed on the mandrel; and   an annular deformable cantilever element and an annular deformable ramp element disposed adjacent one another on the mandrel between the upper and lower supporting members,
 wherein the annular deformable cantilever element and the annular deformable ramp element have a conical interface between them, the interface forming an angle less than 90 degrees relative to an axis of the mandrel. 
   
   
   
       2 . The packing element system of  claim 1 , wherein the angle is in the range from 40 degrees to 60 degrees. 
   
   
       3 . The packing element system of  claim 1 , wherein the angle is greater than 45 degrees. 
   
   
       4 . The packing element system of  claim 1 , wherein the annular deformable cantilever element has an outer surface having an axial length that is longer than an axial length of an outer surface of the annular deformable ramp element. 
   
   
       5 . The packing element system of  claim 1 , wherein the annular deformable cantilever element has a supporting member interface, at least a portion of which is perpendicular to the axis of the mandrel. 
   
   
       6 . The packing element system of  claim 1 , wherein the annular deformable ramp element with an axial length of an inner surface that is longer than an axial length of an inner surface of the annular deformable cantilever element. 
   
   
       7 . The packing element system of  claim 1 , wherein the annular deformable ramp element has a supporting member interface, at least a portion of which is perpendicular to the axis of the mandrel. 
   
   
       8 . The packing element system of  claim 1 , wherein the annular deformable cantilever element includes an inner surface in contact with the mandrel and a bevel at at least one end of the inner surface. 
   
   
       9 . The packing element system of  claim 8 , wherein the inner surface of the annular deformable cantilever element has a bevel at each end of the inner surface. 
   
   
       10 . The packing element system of  claim 1 , wherein the annular deformable ramp element includes an inner surface in contact with the mandrel and a bevel at at least one end of the inner surface. 
   
   
       11 . The packing element system of  claim 8 , wherein the inner surface of the annular deformable ramp element has a bevel at each end of the inner surface. 
   
   
       12 . The packing element system of  claim 1 , wherein one of the upper supporting member or the lower supporting member is stationary relative to the mandrel. 
   
   
       13 . The packing element system of  claim 1 , wherein both the upper supporting member and the lower supporting member are slidingly engaged with the mandrel. 
   
   
       14 . The packing element system of  claim 1 , further comprising a second annular deformable ramp element,
 wherein the annular deformable cantilever element is disposed between said first mentioned annular deformable ramp element and the second annular deformable ramp element,   wherein the annular deformable cantilever element and the second annular deformable ramp element have a second conical interface between them, the second conical interface forming a second angle less than 90 degrees relative to an axis of the mandrel.   
   
   
       15 . The packing element system of  claim 1 , wherein the upper supporting member and the lower supporting member are both cones. 
   
   
       16 . The packing element of  claim 1 , wherein at least one of the upper supporting member or the lower supporting member is formed of a metal. 
   
   
       17 . The packing element of  claim 1 , wherein one of the supporting members comprises a piston located within a cylinder and mounted to the mandrel for relative axial movement. 
   
   
       18 . A packing element system for sealing a well tool against an outer tubular member, the packing element system comprising:
 a mandrel having disposed thereon an upper supporting member and a lower supporting member, one of the supporting members being movable toward the other supporting member;   a cantilever element and a ramp element disposed between the upper and lower supporting members, each of the cantilever element and the ramp element having cylindrical inner and outer diameters, a supporting member end that interfaces with one of the supporting members, and a conical end, the conical ends interfacing with each other and defining a conical angle relative to an axis of the mandrel; and   the cantilever element and the ramp element each being formed of a deformable material so that axial movement of one of the supporting members toward a set position extrudes both the cantilever element and the ramp element into sealing contact with the outer tubular member.   
   
   
       19 . The packing element system of  claim 18 , wherein at least a portion of each of the supporting member ends of the cantilever element and the ramp element is perpendicular to the axis of the mandrel. 
   
   
       20 . The packing element system of  claim 18 , further comprising a second ramp element,
 wherein the cantilever element is disposed between said first mentioned ramp element and the second ramp element,   wherein the cantilever element and the second ramp element have a second conical interface between them, the second conical interface forming a second angle less than 90 degrees relative to an axis of the mandrel.   
   
   
       21 . A method of sealing a wellbore, the method comprising the steps of:
 (a) running a string having a packing element system attached thereto into a bore of a wellbore having a wellbore casing, the packing element system having a cantilever element and a ramp element disposed along a mandrel having an axis, wherein the cantilever element is disposed against the ramp element to provide an interface between the cantilever element and the ramp element, the interface forming an angle less than 90 degrees;   (b) applying an axial load to force the cantilever element and the ramp element against each other, causing the ramp element to wedge under the cantilever element and force the cantilever element radially outward into sealing engagement with the wellbore casing; and   (c) continuing to apply the axial load causing the ramp element to move radially outward into sealing engagement with the wellbore casing.   
   
   
       22 . The method of  claim 21 , wherein the cantilever element and the ramp element are formed of elastomeric materials. 
   
   
       23 . The method of  claim 21 , wherein the angle is in the range from 40 degrees to 60 degrees. 
   
   
       24 . The method of  claim 21 , wherein the angle is greater than 45 degrees.