Patent attributes
A well system includes a tubular string comprising a plurality of tubular segments and positioned in a wellbore drilled into a subterranean zone, and a landing sub connected to a bottom end of one of the plurality of tubular segments. The landing sub includes a landing sub central bore and a landing sub locking profile on an inner surface of the landing sub central bore. The well system also includes a valve assembly configured to be pumped down the tubular string by fluid flowing in a downhole direction through the tubular string and to land within the landing sub central bore. The valve assembly includes a main body with a valve central bore and a flapper configured to pivot between an open position and a closed position. In the closed positon the flapper seals against a flapper seat and blocks fluid from flowing in an uphole direction through the valve central bore. The valve assembly also includes a rupture disc positioned in the valve central bore and configured to rupture in response to an application of a predetermined fluid pressure and configured to block fluid from flowing through the valve central bore when in an unruptured state. The valve assembly also includes one or more valve body setting dogs positioned on an outer surface of the main body and configured to lock into the landing sub locking profile and thereby limit axial movement of the main body within the landing sub.