Mechanical lockout for pressure responsive downhole tool

摘要

An improved mechanical system selectively locks the tester valve of an annulus pressure responsive tester valve in position for an indeterminate number of well annulus pressure cycles. The tester valve also features a multi-range metering cartridge which is operable to meter fluid over a wide range of differential pressures. The metering cartridge provides an adjustable resistance flow path which permits fluid flow across the cartridge. The resistance of the flow path is adjustable by selectively diverting the fluid through a series of fluid flow resistors. Resistance may be increased either by adding a number of flow resistors serially or by adding a single flow resistor which itself provides a greater fluid flow resistance.