Master Flo Valve Inc.

Other

Hydril Company

Harry Richard Cove

Larry J Bohaychuk

John D Muchow

Loren Kowalchuk

Loren G Kowalchuk

The invention provides a choke system with hydraulic circuits which provide choke valve positioning that can be varied by the use of incremental steps. The incremental movement action in either the opening or closing direction is accomplished through the use of one of the two hydraulic slave cylinders which can either add or subtract a fixed volume of hydraulic fluid from the choke actuator. A series of check valves provides direction for flow in the hydraulic lines, locking of the choke actuator, and re-filling of the slave cylinders during operation. The system eliminates excessive lines or solenoid valves and avoids the need for mechanical locking mechanisms. Preferred embodiments include a 'fast close' system which, instead of running through a series of steps to close the valve, provides valve control in a fast close line to move the choke actuator to the full closed position from anywhere in the travel over a shorter period of time than through normal stepping operation.

Linear hydraulic stepping actuator with fast close capabilities

In a sub-sea wellhead insert-type choke valve having a bonnet, a pair of pressure transmitters are mounted in the bonnet. One transmitter is connected by a passageway with the annular clearance between the cartridge of the insert assembly and the valve body. This transmitter measures the pressure of the fluid in the clearance and transmits signals indicative thereof to a receiver at surface. The other transmitter is connected by a passageway with the fluid in the valve outlet, measures the pressure of this fluid and transmits signals indicative thereof to the receiver. In this way the high and low pressures upstream and downstream of the choke valve flow trim are monitored by transmitters, which can be serviced by bringing the insert assembly to surface.

Choke valve with pressure transmitters

A reverse flow insert assembly is provided wherein the flow trim of the choke valve is positioned horizontally within the tubular cartridge, so that the cage bore outlet is aligned with the valve body side opening. A collar is provided to throttle the flow ports of the cage. The valve stem assembly is adapted to bias the collar along the horizontal side wall of the cage. The resulting insert assembly can be positioned in the valve body to modify the valve for fluid injection service on a sub-sea wellhead.

Insert assembly for a wellhead choke valve

In a choke valve having a cage with external sleeve flow trim, the large ports of the cage are aligned with the axis of the inlet bore and a deflection bar is positioned at the top end of the main bore, opposite to the inlet bore. The flow patterns within the choke are consequently altered with significant reduction of localized erosional wear areas.

Choke valve for throttling fluid flow

A choke is provided having a stationary tubular flow nozzle with throttling ports formed through its side wall. A movable tubular throttling ring may be moved over the nozzle to restrict or close the ports. The required liquid-tight seal or shut-off is obtained with annular seal surfaces formed on the nozzle and ring but remote from and upstream of the ports, so that erosion of these seal surfaces, by the high velocity streams passing through the ports, is minimized.

Choke for drilling or production use

A fluid flow control valve especially adapted for use during well drilling operations as a drilling choke is disclosed. A replaceable ported seat and movable tubular flow control element cooperate to control flow through the angled body valve housing. The flow closure mechanism is operating fluid pressure balanced for ease of valve operation during extreme pressure working conditions. Internal flow control working parts of the valve are rugged in construction and assemblage. The portions of the valve subject to wear or flow erosion are also easily replaced when required. An indicator is arranged to signal incipient failure of the replaceable parts of the valve in order that they may be replaced prior to the occurrence of a major failure.

Growing community of inventors

Edmonton, Canada

Harry Richard Cove