Patent ID: 7841410
Filing Date: 2010-11-30
Classification: E21B

Abstract:
1. A ball and plug dropping head for use in sequentially dropping one or more balls and plugs into a well tubing, comprising: a) a housing having an inlet at its upper end adapted to be fluidly connected in line with the lower end of a top drive, an outlet generally aligned with the inlet; b) the housing having an inner surface surrounding an outer bypass channel and an inner flow channel, wherein each said channel connects to the inlet and the outlet; c) a plurality of valving members spaced between the inlet and the outlet, each valving member having an inner valve with a flow bore, and being movable between open and closed positions, each valving member having an outer valve that is in an open position when the inner valve is closed and in a closed position when the inner valve is open, said outer valve presenting a curved surface to the housing inner surface when the inner valve is open, each outer valve not valving flow in the bypass channel when the inner flow channel is closed; d) canisters in the housing that separate said inner and bypass fluid flow channels, said bypass channel enabling fluid to bypass the inner valve and the inner flow channel when the outer valve is in the open position and the inner valve is in the closed position; e) wherein the inner valve does not valve fluid flow in the bypass flow channel when the inner valve is in the closed position; f) wherein fluid flow flows around the inner valve and in between the canisters and the housing inner surface when it is in the closed position and through the inner valve when it is in the open position; g) each canister being a sliding sleeve above each inner valve that is configured to support a ball or plug when the inner valve below the sleeve is closed; and h) wherein in the open position each inner valve flow bore permits a ball or plug to pass therethrough, and circulating fluid to pass downwardly therethrough when neither a ball nor plug is in the inner valve flow bore.