Patent ID: 6138751
Filing Date: 2000-10-31
Classification: E21B

Abstract:
A hanger assembly, comprising:a wellhead housing having a cylindrical bore and an annular recess therein;an inwardly facing annular ramp disposed in said annular recess of said wellhead housing;a locking ring having an outwardly facing wedge surface, said wedge surface positioned on said inwardly facing annular ramp, said locking ring biased radially outwardly to initially adopt a position not projecting into said cylindrical bore of said wellhead housing;a casing hanger axially moveable within said cylindrical bore of said wellhead housing, said casing hanger including a plurality of radially outwardly biased spring fingers; and,said plurality of spring fingers deflected radially inwardly by engagement with said cylindrical bore of said wellhead housing until aligned with said annular recess of said wellhead housing whereupon said plurality of spring fingers expand radially outwardly to engage said locking ring and force said locking ring axially along said wedge surface of said inwardly facing annular ramp and contract said locking ring radially inwardly and said locking ring grips the external surface of said casing hanger.