Well completion system with well control valve

摘要

A system for selective production from, and stimulation of, subterranean production zones while improving productivity and enhancing control of the well. Portions of a production tubing string and an internal stimulation/shifter string are assembled and run together as completion segments. Consecutive completion segments, with each segment including packers that surround sleeves and terminate at the upper end in a well control valve, are run into the cased wellbore so that the acid flow ports operated by sleeve valve assemblies are placed proximate the perforations of prospective production zones. The production zones are then stimulated as the stimulation/shifter string is moved progressively outward placing acid at each consecutive zone. The stimulation/shifter string is then removed from the production tubing string, mechanically closing the well control valve assembly by tubing manipulation. A well control valve assembly prevents flow from or to completion segments further downhole from the well control valve assembly once the stimulation/shifter string has been removed from the production tubing string. The well control valve assembly features a shaped flapper plate which, when opened, conforms closely to the shape and size of the production tubing string's interior diameter. The flapper plate is biased toward a closed position by a compression spring arrangement that includes an arm which levers the plate upward toward a seating surface. The valve assembly's closure is mechanically induced and is not responsive to a sensed well condition. Reopening of the valve assembly is accomplished by insertion into the assembly of a tubular member, or "stinger", which is incorporated into a running arrangement. The stinger is described in relation to a seal assembly which is capable of reopening the well control valve and securing it in the open position. The seal assembly is incorporated into a running arrangement and inserted into the valve assembly to open the valve assembly and seal the connection between the seal assembly and the well control valve assembly.