METHOD AND APPARATUS FOR RETAINING WEIGHTED FLUID IN A TUBULAR SECTION

摘要

A floating apparatus for use in a casing string and especially for use in offshore casing operations. The apparatus includes a valve configured such that, when there is a pressure differential across the valve below a predetermined mid-pressure threshold, the valve prevents fluid flow and, when the pressure differential exceeds a predetermined high-pressure threshold, said valve non-resiliently allows fluid flow across the valve.