Selectively activated float equipment

A valve for a well pipe, the valve comprising:

• a valve collar connectable to the well pipe, wherein the valve collar comprises an indexing lug;
• an index piston coaxially positioned within the valve collar for longitudinal translation within the valve collar between closed, flow-open, and locked-open configurations, wherein the index piston comprises an index pattern comprising closed, flow-open, and locked-open positions such that when the indexing lug is positioned at the closed, flow-open, and locked-open positions, the index piston is configured in the closed, flow-open, and locked-open configurations, respectively;
• a detent in the index piston, wherein the detent restricts fluid flow in a circulation direction through a flow path through the index piston;
• a spring that biases the index piston toward the closed and locked-open configurations;
• and
• a plug of the valve collar that mechanically communicates with the index piston to be in corresponding closed, flow-open, and locked-open configurations.

A method of regulating fluid circulation through a well casing, the method comprising:

• attaching a valve to the casing;
• running the valve and casing into the well, wherein the valve is in a closed configuration to maintain relatively higher fluid pressure outside the casing compared to the fluid pressure in the inner diameter of the casing;
• circulating fluid down the inner diameter of the casing and through the valve to the outside of the casing, wherein the valve is manipulated by the fluid circulation to an open configuration;
• and
• ceasing the circulating fluid, wherein the valve is manipulated to a locked-open configuration.