Baker Hughes Corporation

Mark S Megill

Clifford H Beall

Michael S Rawson

Doug Trott

Steve Rosenblatt

Kevin R Plunkett

A flapper equalizer plunger embodies a unitary coiled spring that is compressed by the flow tube to shift the plunger to equalize pressure across the flapper before the flow tube tries to move the flapper. The hydraulic control system then need only to overcome the force of a flapper pivot spring to swing the flapper 90 degrees to an open position behind the flow tube. The integral spring is produced with a wire EDM technique and can be symmetrical or asymmetrical around its periphery as a way of offsetting off-center impact from the bottom of the flow tube. The plunger can be rotationally locked if it is asymmetrical. The pitch can be constant or variable and the output force greatly exceeds the force provided by an independent coiled spring.

Flapper equalizer with integral spring

A downhole valve that operates on turning of a member having a passage through it with a control system also features a passage from above an uphole seat for the member which communicates to the isolated passage within the member when the valve is closed. The passage features a check valve assembly that preferably has redundant sealing features and filters to prevent debris entry. Pressure applied from above the closed member gets through the check valve assembly to equalize the higher pressure below the ball with the pressure raised in the ball from pressure application at the surface. Removal of the applied pressure reseats the check valve or valves to allow the hydraulic system to rotate the member while the member is no longer subject to a high differential pressure.

Multi-stage pressure equalization valve assembly for subterranean valves

The invention relates to a pair of matched surfaces usable in sealing a downhole subsurface safety valve. The continuous seat and the matching flapper profile feature a surface that is around its periphery transverse to the longitudinal axis of the seat and the flapper. The seating surface, if extended in a two-dimensional plane, defines an undulating shape which can be a sinusoidal shape in the preferred embodiment. The result is an improvement in the performance of the metal-to-metal contact between the seat and the flapper, coupled with a self-centering effect when the seating surface on the flapper, which is formed adjacent a shoulder, is presented in opposition to the seat. Additionally, the transverse undulating seat can have an embedded groove which accommodates a resilient seal, preferably PTFE or Teflon.RTM..

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Tulsa, OK, United States of America

Mark S Megill