| 摘要 |
A subsea wellhead assembly comprises a housing 11, a hanger 21 and a split load ring 31. The wellhead housing defines a bore 13 containing at least one groove with a conical upward facing load shoulder 17 that is inclined at an angle 'b'. The hanger is lowered into the housing, and has at least one conical downward facing load shoulder 25 that is inclined at an angle 'a'. Angle 'a' is less relative to the axis of the bore than angle 'b'. The split load ring is employed having an inner profile 34 that slidingly engages the downward facing load shoulder and an outer profile 33 that slidingly engages the upward facing load shoulder. The load ring is carried by the hanger for movement between a retracted position (Fig. 2), where the hanger is free to travel in the housing, and an expanded position where the outer profile engages with the housing load shoulder. The difference in angle between the hanger and housing load shoulders enables the split load ring to overcome the frictional resistance of the expansion movement. The assembly is designed for use with full bore wellheads; that is wellheads without support shoulders that narrow the bore. |
