Curved flapper valve
AssigneeSchlumberger Technology Corporation
InventorsAlfred Hernandez, Juan A. Campos
Life of this patent
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Abstract
A flapper valve having a curved flapper and a seat, the flapper and seat each having complementary undulating and tapered perimeters, with sealing surfaces designed to maintain seal integrity under higher pressure, for a given outer diameter to inner diameter ratio, compared to prior art flapper valves.
Claims24
A flapper valve for deployment in a wellbore, comprising:
- a housing;
- a bore through the housing having a longitudinal axis;
- a curved flapper hingedly connected to the housing and rotatable between an open state to allow flow through the bore and a closed state to prevent flow through the bore, the flapper having a first sealing surface;
- a seat within the housing, the seat having a second sealing surface substantially conforming to the first sealing surface and on which the first sealing surface bears when the flapper is in the closed state;
- and in which
- the first and second surfaces are variably tapered such that a bearing force from the first surface onto the second surface has, along a first portion of the sealing surfaces, a first component directed radially inward relative to the longitudinal axis and, along a second portion of the sealing surfaces, a second component directed radially outward relative to the longitudinal axis.
A flapper valve for deployment in a wellbore having wellbore fluids, comprising:
- a housing having a bore therethrough about a longitudinal axis;
- a flapper having an undulating and tapered first annular perimeter, the flapper being rotatable in the housing;
- and
- a seat in the housing having an undulating and tapered second annular perimeter substantially conforming to the first annular perimeter and in sealing engagement with the first annular perimeter when the flapper is in a closed position such that the flapper opposes collapse forces applied by the wellbore fluids onto the seat.
A flapper valve for deployment in a wellbore having wellbore fluids, comprising:
- a housing having a bore therethrough about a longitudinal axis;
- a flapper having an undulating and tapered first annular perimeter, the flapper being rotatable in the housing;
- and
- a seat in the housing having an undulating and tapered second annular perimeter substantially conforming to the first annular perimeter and in sealing engagement with the first annular perimeter when the flapper is in a closed position such that the seat opposes collapse forces applied by the wellbore fluids onto the flapper.
A flapper valve for deployment in a wellbore having wellbore fluids, comprising:
- a housing having a bore therethrough about a longitudinal axis;
- a flapper having an undulating and tapered first annular perimeter, the flapper being rotatable in the housing;
- and
- a seat in the housing having an undulating and tapered second annular perimeter substantially conforming to the first annular perimeter and in sealing engagement with the first annular perimeter when the flapper is in a closed position such that the flapper and the seat mutually and reciprocally opposes collapse forces applied by the wellbore fluids onto the flapper and the seat.
A flapper valve subassembly for deployment in a wellbore, comprising:
- a flapper having a high pressure surface, a low pressure surface, and an undulating sealing surface extending between the high and low pressure surfaces, the sealing surface variably tapering from the high pressure surface to the low pressure surface;
- a seat having a mating sealing surface substantially conforming to the sealing surface of the flapper;
- and in which
- the taper angle of the first sealing surface mating at a seat crest is between an outward angle of five degrees and an inward angle of sixty degrees relative to a line perpendicular to the longitudinal axis and the taper angle of the first sealing surface mating at a seat valley is between an outward angle of thirty degrees and an inward angle of sixty degrees relative to a line perpendicular to the longitudinal axis.
A method to reduce relative deflection of a flapper and a seat in a flapper valve, the flapper and the seat having mating sealing surfaces, the method comprising:
- tapering at least a portion of the sealing surfaces radially inward, radially outward, or a combination of radially inward and outward, such that the flapper supports the seat, the seat supports the flapper, or the flapper and seat mutually and reciprocally support each other to oppose collapse forces applied by wellbore fluids.
Dependencies are inferred from the claim text.