Patent ID: 7017671
Filing Date: 2006-03-28
Classification: E21B

Abstract:
1. A fluid retaining apparatus, in a top drive assembly for retaining fluid in the top drive assembly when a tubular is disconnected therefrom, comprising: a first tubular body adapted to be detachably mounted below said top drive; a second tubular body adapted to be inserted into said first tubular body; said second body being a downwardly extending closure member, said closure member having a bore extending axially therethrough; an axially movable piston disposed within said second body, said piston having a flange extending radially outwardly therefrom into contact with said body, a passage having a cross-sectional area for the flow of fluid therethrough, said passage being substantially coaxial with said bore, and a top side; said closure member having an upper side, wherein said upper side further comprises a plurality of flow passages, each having a cross-sectional area, such that the sum of the cross-sectional areas of said plurality of flow passages at least substantially equals the cross-sectional area of said passage within said piston; said upper side further having a plurality of check valves to allow fluid to flow upwardly therethrough, wherein said flow allows downhole pressure to be detected; a ring member engaging the lower end of said body and extending radially inwardly into contact with a compression spring; and said compression spring disposed within said body and compressed between said flange and said ring member, wherein said compression spring urging said piston axially upward blocking said plurality of flow passages, thereby preventing the downward flow of fluid therethrough.