Flow router with retrievable valve assembly

Abstract

Embodiments of the present invention provide a flow router for inclusion in a production string that is for insertion in a well casing, the flow router comprising a retrievable assembly removably inserted in a perforated cover and a valve of the retrievable assembly including a valve body extending between opposed first and second ends of the valve to define an axial flow path, the retrievable assembly retrievable to and removable from an open end of the production string.

What is claimed is: 
     
         1 . A production string comprising:
 production tubing, casing, and a flow router for insertion in the casing;   the flow router including a retrievable assembly removably inserted in a perforated cover, the retrievable assembly including a valve body, a valve shuttle, and a spring that biases the shuttle;   a perforated cover inlet for receiving a pumped flow and a perforated cover exit for forwarding the pumped flow to production tubing;   the valve shuttle within the valve body and the valve body inserted in the perforated cover;   a first annulus between the retrievable assembly and the perforated cover and a second annulus between the perforated cover and the casing;   a valve body spill port in fluid communication with the first annulus via the cover perforation and the first annulus in fluid communication with the second annulus via the perforations in the cover;   the valve for passing an axial flow when (i) the shuttle blocks the spill port and (ii) a shuttle through hole is not blocked; and,   the valve for blocking an axial flow when (i) the shuttle through hole is blocked and (ii) the shuttle does not block the spill port;   wherein the retrievable assembly is retrievable to and removable from an open end of the production string.   
     
     
         2 . The production string of  claim 1  wherein spring expansion tends to close the spill port. 
     
     
         3 . The production string of  claim 2  wherein a spring end is near the perforated cover inlet. 
     
     
         4 . A method of protecting a pump in a downhole production string, the pump taking suction from a reservoir, the method comprising the steps of:
 locating a flow router in the production string between the pump and a tubing string, the flow router including an assembly removable from a perforated cover, the removable assembly including a bypass valve;   providing a reservoir production flowpath through the pump, the flow router and the tubing string;   providing a reservoir return flowpath through an annulus encircling the production flowpath;   wherein during a reservoir production operation, surfacing fluid via the production flowpath when a shuttle of the valve blocks a valve spill port and when a shuttle through hole is not blocked;   wherein during a reservoir production operation, fluid is surfaced via the production flowpath when the valve shuttle blocks a valve spill port and when a shuttle through hole is not blocked;   wherein during a reservoir replenishment operation for protecting the pump, fluid is returned to the reservoir via the return flowpath when the shuttle does not block the valve spill port and when the shuttle through hole is blocked;   wherein during a removable assembly recovery operation, the removable assembly is recovered from an open end of the production tubing; and,   wherein during a removable assembly installation operation, the removable assembly is installed in the perforated cover.   
     
     
         5 . The method of  claim 4  wherein a spring biases the shuttle such that it tends to close the spill port. 
     
     
         6 . The method of  claim 5  wherein a spring end is near a perforated cover inlet. 
     
     
         7 . The method of  claim 6  wherein a production flow tends to unblock the shuttle through hole. 
     
     
         8 . The method of  claim 6  wherein the spring is compressed during a transition from a reservoir production operation to a reservoir replenishment operation. 
     
     
         9 . A retrievable assembly method for producing an oil well comprising the steps of:
 lining the well with a casing;   assembling a tubing string including an in-line perforated valve cover and an end-of-line pump;   lowering the tubing string into the casing;   when the pump reaches its intended location with respect to a reservoir, fixing the tubing string in place;   providing a retrievable valve assembly including a bypass valve with a valve body enclosing a spring biased shuttle;   suspending the retrievable valve assembly from a wireline;   lowering the retrievable valve assembly into the tubing using the wireline until it is seated and locked in the valve cover;   recovering the wireline;   operating the pump and beginning to surface fluid from the reservoir;   shutting the pump down;   lowering the wireline and coupling the wireline to the retrievable valve assembly;   with the wireline, pulling the retrievable valve assembly toward the surface with sufficient force to release locks holding it in the cover; and,   spooling the wireline and raising the retrievable valve assembly until it is recovered from the tubing;   wherein the valve is mechanically operated and valve operation is autonomous.   
     
     
         10 . The retrievable assembly method of  claim 9  wherein the spring biases the shuttle such that it tends to close a spill port. 
     
     
         11 . The retrievable assembly method of  claim 10  wherein a spring end is near a perforated cover inlet.