Abstract: A float valve assembly is configured to be positioned within in a central bore of a tubular string disposed in a wellbore drilled into a subterranean zone. The float valve assembly includes a valve main body and a plunger, and the plunger is biased by a spring towards a closed position and is configured to open in response to a fluid pressure in a downhole direction. The surface of the plunger main body includes a plurality of substantially flat lateral faces forming a pyramid. A hydrophilic nano-coating comprising particles with sizes of between 1 and 100 nanometers is disposed on at least a portion of the surface of the plunger main body.

Abstract: A diverter system is configured to control a direction of drilling fluid or gas from a well bore to a surface platform. The diverter system includes a housing configured to receive a casing from a well bore, at least one outlet configured to direct flow of a drilling fluid or gas out of the housing, and a packing element assembly within the housing and coupled to the housing. The packing element assembly includes a first packing element affixed to the housing, the first packing element including at least one balloon configured to expand in response to an actuation input, and a second packing element concentrically within the first packing element, the second packing element including a first half and a second half, the first half coupled to the second half by a plurality of elastic elements.