PRESSURE-CONTROLLED ACCUMULATOR CHARGING VALVE SYSTEM FOR OIL FIELD DOWNHOLE TOOLS

摘要

Abstract of the DisclosureApparatus for pressure charging pressure accumulators inapparatus downhole in a well, wherein a first valve system admitspressured fluid into an accumulator from a well tubing such as adrill string in response to well tubing - accumulator differen-tial pressure and a second valve system releases pressured fluidfrom the accumulator to the well tubing in response to accumu-lator - well tubing differential pressure. The apparatusutilizes valve assemblies called "fuses", which can be used foraccumulator pressure adjustments in lower well tubing pressureranges and which close in response to higher fluid pressures inthe well tubing so that well tubing pressure can be used to dowork in the well such as to operate a piston actuator, or thelike.