Large bore assembly and spherical swivel joint

Abstract

A zipper stack is connected to a wellhead by way of a single straight-line pipe connection. A manifold assembly with high- and low-pressure lines feeding into one or more fluid lines with a large internal bore diameter supplies fracturing fluid to the zipper stack, which in turn supplies the fracturing fluid to the wellhead. A spherical swivel joint with multiple bearings may be used to the connect various piping and fluid lines disclosed herein.

What is claimed is: 
     
         1 . A spherical swivel joint, comprising:
 a first yoke comprising a first flange and defining a first fluid passage;   a first bearing coupled to the first yoke;   a second yoke comprising a second flange and defining a second fluid passage;   a second bearing coupled to the second yoke; and   a crossover spool coupled to the first bearing and the second bearing, the crossover spool defining a third fluid passage that creates an aggregate fluid pathway comprising the first fluid passage, the second fluid passage, and the third fluid passage.   
     
     
         2 . The spherical swivel joint of  claim 1 , wherein the crossover spool is movable through movement of the first bearing. 
     
     
         3 . The spherical swivel joint of  claim 2 , wherein the crossover spool is free to move at least one of the x-, y-, or z-directions based on coupling to the first bearing. 
     
     
         4 . The spherical swivel joint of  claim 3 , wherein the crossover spool is movable up to seven degrees relative to a longitudinal axis of the first yoke. 
     
     
         5 . The spherical swivel joint of  claim 1 , wherein the first bearing is positioned inside a cylindrical bearing housing. 
     
     
         6 . The spherical swivel joint of  claim 1 , further comprising one or more longitudinally extending flange connectors extending from the first flange for mating with reciprocal flange receptacles, thereby connecting the first flange to external flow iron components. 
     
     
         7 . The spherical swivel joint of  claim 1 , wherein the flange is configured to be threadably connected to external flow iron components. 
     
     
         8 . The spherical swivel joint of  claim 1 , wherein the crossover spool enables the second bearing to be moved up to five inches off of a longitudinal axis defined by the first yoke and spanning through the first bearing. 
     
     
         9 . The spherical swivel joint of  claim 1 , further comprising:
 a first bearing housing internally containing the first bearing; and   a second bearing housing internally containing the second bearing, the second bearing housing being movable along a longitudinal axis relative to the first bearing housing.   
     
     
         10 . The spherical swivel joint of  claim 1 , wherein the aggregate fluid pathway measures at 4-7 inches in diameter. 
     
     
         11 . The spherical swivel joint of  claim 1 , wherein the first bearing includes an inner ring defining a convex surface and an outer ring defining a concave surface. 
     
     
         12 . The spherical swivel joint of  claim 1 , wherein the crossover spool defines an external convex annular surface at an end potion of the first yoke opposite the first flange. 
     
     
         13 . The spherical swivel joint of  claim 1 , wherein the crossover spool defines an external convex annular surface at an end potion of the first yoke opposite the first flange. 
     
     
         14 . A system for delivering fracturing fluid to a wellhead through a zipper stack, wherein the zipper stack is coupled to the wellhead, the system comprising:
 a manifold assembly comprising at least one tubular member defining a fluid flow line for supplying the fracturing fluid to the zipper stack, the manifold assembly comprising and a flow fitting as an outlet for the fracturing fluid to the zipper stack; and   a first spherical swivel joint comprising:
 a first yoke with a first flange connectable to the flow fitting of the manifold assembly, the first yoke defining a first fluid passage for the fracturing fluid, 
 a first bearing coupled to the first yoke, 
 a second yoke with a second flange, the second yoke defining a second fluid passage for the fracturing fluid, 
 a second bearing coupled to the second yoke, and 
 a first crossover spool coupled to the first bearing and the second bearing, the first crossover spool defining a third fluid passage that creates a first aggregate fluid pathway comprising the first fluid passage, the second fluid passage, and the third fluid passage for the fracturing fluid to pass from the manifold assembly to the zipper stack. 
   
     
     
         15 . The system of  claim 14 , wherein the zipper stack is coupled to the wellhead along a single straight-line pipe between a zipper stack and the wellhead for supplying the fracturing fluid to the wellhead. 
     
     
         16 . The system of  claim 15 , wherein the zipper stack is connected to the wellhead through a second spherical swivel joint, the second spherical swivel joint comprising:
 a third yoke with a third flange connectable to the zipper stack, the third yoke defining a third fluid passage for receiving the fracturing fluid,   a third bearing coupled to the third yoke,   a fourth yoke with a fourth flange, the fourth yoke defining a fourth fluid passage for the fracturing fluid,   a fourth bearing coupled to the fourth yoke, and   a second crossover spool coupled to the third bearing and the fourth bearing, the second crossover spool defining a fifth fluid passage that creates a second aggregate fluid pathway comprising the third fluid passage, the fourth fluid passage, and the fifth fluid passage for the fracturing fluid to pass from the zipper stack to the wellhead.   
     
     
         17 . The system of  claim 14 , wherein the zipper stack is configured to direct at least part of the fracturing fluid to another zipper stack connected to another wellhead. 
     
     
         18 . The system of  claim 14 , wherein the first spherical swivel joint comprises an inner bore diameter of 7 inches. 
     
     
         19 . A system for delivering fracturing fluid to a wellhead, the system comprising:
 a zipper stack coupled to a wellhead; and   a spherical swivel joint comprising:
 a first yoke with a first flange connectable to the zipper stack, the first yoke defining a first fluid passage for the fracturing fluid, 
 a first bearing coupled to the first yoke, 
 a second yoke with a second flange, the second yoke defining a second fluid passage for the fracturing fluid, 
 a second bearing coupled to the second yoke, and 
 a crossover spool coupled to the first bearing and the second bearing, the crossover spool defining a third fluid passage that creates an aggregate fluid pathway comprising the first fluid passage, the second fluid passage, and the third fluid passage for the fracturing fluid to pass to the zipper stack. 
   
     
     
         20 . The system of  claim 19 , further comprising a manifold assembly comprising a fluid line with an internal bore having a diameter between 4-9 inches is connected to the flange of the second yoke of the spherical swivel joint, wherein the manifold assembly supplies the fracturing fluid to the spherical swivel joint for passage to the zipper stack.