Abstract: Valves comprise a chamber having a piston disposed therein. One side of the piston defines a hydrostatic chamber in fluid communication with an outside environment, such as wellbore annulus, through a port. Operatively associated with the piston on the other side is a sleeve in sliding engagement with an inner mandrel. The inner mandrel comprises a port that is initially blocked by the sleeve. Upon an increase in pressure within the annulus, the piston is moved causing the port in the sleeve to align with the port in the inner mandrel thereby allowing fluid to flow from the annulus into the bore of the inner mandrel. As a result, fluid can be circulated through the valve, or pressure within the annulus can be reduced. A return member is operatively associated with the piston to urge the piston toward the closed position after pressure within the wellbore annulus is reduced.

Abstract: Valves comprise a chamber having a piston disposed therein. One side of the piston defines a hydrostatic chamber in fluid communication with an outside environment, such as wellbore annulus, through a port. Operatively associated with the piston on the other side is a sleeve in sliding engagement with an inner mandrel. The inner mandrel comprises a port that is initially blocked by the sleeve. Upon an increase in pressure within the annulus, the piston is moved causing the port in the sleeve to align with the port in the inner mandrel thereby allowing fluid to flow from the annulus into the bore of the inner mandrel. As a result, fluid can be circulated through the valve, or pressure within the annulus can be reduced. A return member is operatively associated with the piston to urge the piston toward the closed position after pressure within the wellbore annulus is reduced.

Abstract: Valves comprise a chamber having a piston disposed therein. One side of the piston defines a hydrostatic chamber in fluid communication with an outside environment, such as wellbore annulus, through a port. Operatively associated with the piston on the other side is a sleeve in sliding engagement with an inner mandrel. The inner mandrel comprises a port that is initially blocked by the sleeve. Upon an increase in pressure within the annulus, the piston is moved causing the port in the sleeve to align with the port in the inner mandrel thereby allowing fluid to flow from the annulus into the bore of the inner mandrel. As a result, fluid can be circulated through the valve, or pressure within the annulus can be reduced. A return member is operatively associated with the piston to urge the piston toward the closed position after pressure within the wellbore annulus is reduced.

Abstract: An actuator device for setting a downhole tool comprises a piston disposed in an upper reservoir of the device, the piston comprising two actuation areas upon which pressure acts to move the piston. The upper reservoir is in fluid communication with a lower reservoir through a valve that initially restricts the flow of fluid from the first reservoir to the second reservoir. In setting a downhole tool, fluid pressure initially acts on the first actuation area to slowly move the piston toward a set position. After a predetermined length of movement of the piston, the second actuation area is placed in fluid communication with a pressure such that the valve no longer restricts the flow of fluid through the valve, i.e., the total pressure acting on the piston is increased. This increased pressure rapidly moves the piston to actuate, or set, the downhole tool.

Abstract: An actuator device for setting a downhole tool comprises a piston disposed in an upper reservoir of the device, the piston comprising two actuation areas upon which pressure acts to move the piston. The upper reservoir is in fluid communication with a lower reservoir through a valve that initially restricts the flow of fluid from the first reservoir to the second reservoir. In setting a downhole tool, fluid pressure initially acts on the first actuation area to slowly move the piston toward a set position. After a predetermined length of movement of the piston, the second actuation area is placed in fluid communication with a pressure such that the valve no longer restricts the flow of fluid through the valve, i.e., the total pressure acting on the piston is increased. This increased pressure rapidly moves the piston to actuate, or set, the downhole tool.