Pressure-actuated valve and method

A method of activating the bypass opening in a subsurface valve from a remote surface location, comprising:

• selecting a flow restriction ring for positioning within said valve as a function of an anticipated fluid flow and pressure condition to the valve;
• flowing fluid through the flow restriction ring in the valve at the anticipated rate sufficient to shift a flow responsive valve control mechanism from a first position wherein the bypass of the valve is open to a second position wherein the bypass remains open;
• reducing the rate of fluid flow through the valve to shift the valve control mechanism from the second position to a third position wherein the bypass of the valve is closed;
• increasing one of the hydrostatic pressure of static fluid in the valve and the rate of fluid flow through the valve to move the bypass valve control mechanism from the third position to a fourth position wherein the bypass is open;
• reducing one of the hydrostatic pressure of static fluid in the valve and the rate of flow of fluid through the valve to move the bypass valve control mechanism from the fourth position to a fifth position wherein the bypass of the valve remains open;
• and
• circulating fluid from said valve through said bypass in said open position.

A method of operating a downhole subsurface valve from a remote surface location, the subsurface valve positioned in a wellbore along a tubular string, comprising:

• initiating fluid flow through the tubular string and to said valve adequate to shift a flow responsive bypass valve closure mechanism in the valve from a first open position to a second open position;
• reducing the pressure of the fluid in the tubular string and to the valve to mechanically shift the bypass valve closure mechanism to a third open position;
• increasing the pressure of the fluid in the tubular string and to the valve to shift the bypass valve closure mechanism from said third open position to a first closed position;
• and
• lowering the pressure of the fluid in the tubular string and to the valve to allow the valve closure mechanism to shift the bypass to a mechanically retained second closed position.

A bypass valve for positioning downhole in a well bore along a tubular string, the bypass valve being responsive to flow induced pressure changes transmitted to the valve through the tubular string to control the flow of fluid through the valve, comprising:

• a valve housing adapted for fluid communication with the tubular string;
• a bypass valving mechanism movable within said valve housing between an open position which permits fluid flow through said valve housing and a closed position which terminates flow of fluid through said valve housing;
• a flow responsive pressure differential member within said valve housing and responsive to the flow of fluid through said valve housing for moving said valving mechanism axially within said valve housing, the flow responsive differential member including a flow restrictive ring removably positioned within said valve housing for moving said valving mechanism between said open position and said closed position for a selected fluid flow and pressure condition in said valve housing;
• a biasing member for providing a biasing force opposing axial movement of said valving mechanism in response to said pressure differential member;
• and
• a cam device within said valve housing for manipulating said valving mechanism between said open position and said closed position in response to axial movement of said valving mechanism within said housing.