Vibration-Resistant Seal for Downhole Tool

Abstract

A seal ring assembly for a well drilling tool that takes the place of conventional O-rings that are prone to costly downhole failures. In a first embodiment the seal ring assembly is configured with a convex adapter seal ring at one end, a concave adapter seal ring at the other end, and a number of V-shaped component seal rings packed in between the convex and concave adapter seal rings and positioned in the space between a drill collar mandrel and a pressure cylinder of the well drilling tool. In a second embodiment the seal ring assembly is configured with a number of X-shaped component seal rings, each of which is fitted with two O-rings. The seal ring assemblies are able to flex when operating in a bent drill hole so as to maintain seal integrity and prevent fluids from passing through to the electronics region of the well drilling tool.

1 . A seal ring assembly, comprising:
 one or more component seal rings each having a V-shaped concave surface and a V-shaped convex surface;   a convex adapter seal ring with a V-shaped inner surface configured to mate with the V-shaped concave surface of a first one of said one or more component seal rings; and   a concave adapter seal ring with a V-shaped inner surface configured to mate with the V-shaped convex surface of a second one of said one or more component seal rings;   wherein said one or more component seal rings are positioned between the convex adapter seal ring and the concave adapter seal ring.   
     
     
         2 . The seal ring assembly of  claim 1 , wherein the convex adapter seal ring, the concave adapter seal ring, and said one or more component seal rings each have a first lateral side surface positioned adjacent an inner shaft of a well drilling tool and a second lateral side surface positioned adjacent an outer bore of said well drilling tool. 
     
     
         3 . The seal ring assembly of  claim 1 , wherein the inner shaft is a drill collar mandrel and the outer bore is a pressure cylinder, and wherein the concave adapter seal ring further comprises:
 a groove configured on the V-shaped inner surface.   
     
     
         4 . The seal ring assembly of  claim 1 , wherein the inner shaft is a chassis and the outer bore is a drill collar, and wherein the concave adapter seal ring further comprises:
 a groove configured on the V-shaped inner surface.   
     
     
         5 . The seal ring assembly of  claim 1 , wherein said one or more component seal rings each have a concave surface chevron angle that differs from a convex surface chevron angle. 
     
     
         6 . The seal ring assembly of  claim 1 , wherein the convex adapter seal ring has a first planar outer surface perpendicular to a center axis of a well drilling tool; and
 wherein the concave adapter seal ring has a second planar outer surface perpendicular to said center axis of the well drilling tool.   
     
     
         7 . The seal ring assembly of  claim 6 , wherein the well drilling tool has an element configured to exert pressure against either the first planar outer surface or the second planar outer surface. 
     
     
         8 . The seal ring assembly of  claim 7 , wherein said element is one of a threaded nut, a spring, and a drill string connection thread. 
     
     
         9 . A well drilling tool, comprising:
 a drill collar mandrel;   a pressure cylinder;   one or more component seal rings each having a V-shaped concave surface and a V-shaped convex surface;   a convex adapter seal ring with a V-shaped inner surface configured to mate with the V-shaped concave surface of a first one of said one or more component seal rings; and   a concave adapter seal ring with a V-shaped inner surface configured to mate with the V-shaped convex surface of a second one of said one or more component seal rings;   wherein said one or more component seal rings are positioned between the convex adapter seal ring and the concave adapter seal ring.   
     
     
         10 . The well drilling tool of  claim 9 , wherein the convex adapter seal ring, the concave adapter seal ring, and said one or more component seal rings each have a first lateral side surface positioned adjacent said drill collar mandrel and a second lateral side surface positioned adjacent said pressure cylinder. 
     
     
         11 . The well drilling tool of  claim 9 , wherein the concave adapter seal ring further comprises:
 a groove configured on the V-shaped inner surface.   
     
     
         12 . The well drilling tool of  claim 9 , wherein said one or more component seal rings each have a concave surface chevron angle that differs from a convex surface chevron angle. 
     
     
         13 . The well drilling tool of  claim 9 , wherein the convex adapter seal ring has a first planar outer surface perpendicular to a center axis of the well drilling tool; and
 wherein the concave adapter seal ring has a second planar outer surface perpendicular to said center axis of the well drilling tool.   
     
     
         14 . The well drilling tool of  claim 13 , wherein the well drilling tool has a mechanism configured to exert pressure against either the first planar outer surface or the second planar outer surface. 
     
     
         15 . The well drilling tool of  claim 14 , wherein said mechanism is one of a threaded nut, a spring, and a drill string connection thread. 
     
     
         16 . A seal ring assembly, comprising:
 a plurality of X-shaped seal rings each having an X-shaped cross-section and a predefined diameter, each of said plurality of X-shaped seal rings being configured with an inner lateral groove and an outer lateral groove;   a plurality of first O-rings each being respectively configured to be received in the inner lateral groove of one of said plurality of X-shaped seal rings; and   a plurality of second O-rings each being respectively configured to be received in the outer lateral groove of one of said plurality of X-shaped seal rings.   
     
     
         17 . The seal ring assembly of  claim 16 , wherein said plurality of first O-rings each has a mean diameter smaller than said predefined diameter, and said plurality of second O-rings each has a mean diameter larger than said predefined diameter. 
     
     
         18 . The seal ring assembly of  claim 17 , wherein said plurality of first O-rings are configured to be positioned adjacent a drill collar mandrel of a well drilling tool, and said plurality of second O-rings are configured to be positioned adjacent a pressure cylinder of the well drilling tool. 
     
     
         19 . The seal ring assembly of  claim 17 , wherein said plurality of first O-rings are configured to be positioned adjacent a chassis of a well drilling tool, and said plurality of second O-rings are configured to be positioned adjacent a drill collar of the well drilling tool. 
     
     
         20 . The seal ring assembly of  claim 1 , wherein said seal assembly operates to close an extrusion gap, support against radial forces and transfer loading from axial force to radial force.