Multistage Production System and Method

Abstract

A system and method for more efficiently stimulating and producing from a production string. The present invention comprises production tubing; at least one selectively-openable valve assembly located inline with the production tubing; and at least one flapper valve assembly located inline with the production tubing. One flapper valve assembly is associated with each selectively-openable valve assembly. The flapper valve assembly is orientated to impede fluid flow in the downwell direction when closed.

1 . A multistage hydrocarbon production system comprising:
 production tubing;   at least one selectively-openable valve assembly spaced along said production tubing;   at least one flapper valve assembly spaced along said production tubing, there being one of said at least one flapper valve assembly associated with each of said at least one selectively-openable valve assembly;   wherein each of said at least on flapper valve assembly is oriented to impede fluid flow in the downwell direction when closed.   
     
     
         2 . A method of stimulating and producing from a hydrocarbon production zone, the method comprising the steps of:
 running a shifting string through a flapper valve assembly associated with a selectively-openable valve assembly, said shifting string adapted to actuated said flapper valve assembly and said selectively-openable valve assembly, said flapper valve assembly being orientated to impede fluid flow in the downwell direction when close;   actuating said selectively-openable valve assembly to provide a flow path between said production tubing and said hydrocarbon production zone;   displacing a fracing material through said selectively-openable valve assembly;   displacing said shifting string to a position upwell from said flapper valve assembly without closing said selectively-openable valve assembly; and   cause said flapper valve assembly to close.