Patent Application
20160273306
Many industries employ flapper valves to control fluid flow. The flapper valve includes a flapper that allows fluid flow in one direction and prevents fluid flow in a reverse direction. The flapper is pivotally mounted to the valve and shifts between open and closed configurations. In the closed configuration, the flapper typically rests against a valve seat. In some cases, a seal may exist between the flapper and the valve seat. In other cases, the flapper and valve seat meet at a metal-to-metal interface without the use of an additional seal.
A flapper valve includes a valve body having a hinge member. A flapper is pivotally mounted to the valve body through the hinge member. At least one of the valve body and the flapper includes a multi-stage valve seat. The multi-stage valve seat includes a first sealing zone and a second sealing zone that is distinct from the first sealing zone. The first sealing zone is configured to provide pressure containment at the valve body when the flapper is exposed to a first pressure and the second sealing zone is configured to provide pressure containment at the valve body when the flapper is exposed to a second pressure that is greater than the first pressure.
A subsurface exploration system includes an uphole system, and a downhole system including at least one downhole tubular. The at least one downhole tubular includes a flapper valve having a valve body including a hinge member, and a flapper pivotally mounted to the valve body through the hinge member. At least one of the valve body and the flapper includes a multi-stage valve seat. The multi-stage valve seat includes a first sealing zone and a second sealing zone that is distinct from the first sealing zone. The first sealing zone is configured to provide pressure containment at the valve body when the flapper is exposed to a first pressure and the second sealing zone is configured to provide pressure containment at the valve body when the flapper is exposed to a second pressure that is greater than the first pressure.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
A resource exploration system, in accordance with an exemplary embodiment, is indicated generally at 2, in
As shown in
In accordance with an exemplary embodiment, multi-stage valve seat 50 includes a first sealing zone 80 and a second sealing zone 82. As will be detailed more fully below, second sealing zone 82 is formed on a cantilevered region 86 of multi-stage valve seat 50. Second sealing zone 82 is arranged radially inwardly of first sealing zone 80 at second end 43 of valve body 40. Second sealing zone 82 is also axially off-set relative to first sealing zone 80. More specifically, second sealing zone 82 is closer to first end 42 of valve body 40 than first sealing zone 80.
In further accordance with an exemplary embodiment, first sealing zone 80 constitutes a low pressure sealing zone creating a seal at low pressures at about, for example 200-psi (14.1 kgf/cm2). More specifically, a pressure of about 200-psi on flapper 60 urges sealing surface 70 against first sealing zone 80 providing pressure containment and/or preventing fluid passing through valve body 40. Second sealing zone 82 constitutes a higher pressure sealing zone. Pressures above about 200-psi, such as working pressures, acting upon first surface 64 of flapper 60 may cause second sealing zone 82 to elastically deform such that sealing surface 70 also contacts first sealing zone 80 providing additional pressure containment and/or ensuring that fluids do not pass through valve body 40.
At this point it should be understood that exemplary embodiments describe a flapper valve having at least two sealing surfaces, a low pressure sealing surface, and a higher pressure sealing surface. The low pressure sealing surface elastically deforms at higher pressures to provide a more robust closure of the flapper valve. It should also be understood, that while shown as being part of the valve body, the multi-stage valve seat may be formed on the flapper. Further, it should be understood that while shown as being employed in downhole operations, it should be understood that the flapper may be employed in a wide variety of applications in which multi-stage sealing is desirable and should not be considered to be limited to downhole environments, or resource recovery and exploration operations.
The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers, etc.
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value.
While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
