METHOD AND APPARATUS FOR INSERTING A TUBULAR STRING INTO A WELL

摘要

A valve to act as a barrier to fluid movement in a tubular is provided. A flapper in the valve may be opened by application of a selected pressure differential across the flapper. The flapper opens to allow a cylinder to shift and cover the open flapper. A method of placing a tubular string within a well using the valve as an isolation valve to form gas filled chambers for floating the tubular string into the well is also disclosed.