Wellhead seal assembly

A wellhead assembly comprising:

• an outer wellhead member adapted to be anchored in a borehole;
• an inner wellhead member landed within the outer wellhead member, and defining an annulus provided between the inner and outer wellhead members;
• a contoured surface on an exterior surface of the inner wellhead member;
• a seal assembly in the annulus, having a first portion in sealing contact with the outer wellhead member and a second portion in sealing contact with the inner wellhead member outer surface, defining an annular channel between the first and second portions;
• an energizing ring insertable into the channel between the first and second portions of the seal assembly to force the first and second portions apart from each other, the energizing ring having a cam surface on its inner diameter;
• and
• a radially contractable lockdown member supported on the inner portion of the seal assembly and engaged by the cam surface, wherein movement of the energizing ring as it is inserted into the channel, pushes the lockdown member into engagement with a grooved profile on the inner wellhead member.

A method of sealing an annulus between an outer and an inner wellhead member comprising:

• (a) providing a seal assembly with a lockdown member and positioning the seal assembly in the annulus;
• (b) deforming the seal assembly into sealing engagement with the inner and outer wellhead members using an energizing ring;
• and
• (c) setting the lockdown member with the energizing ring to cause it to lock the seal assembly to one of the wellhead members.

A wellhead assembly comprising:

• an annular outer wellhead member adapted to be anchored in a borehole;
• wickers formed on the outer wellhead member inner surface;
• an inner wellhead member landed within the outer wellhead member, the inner wellhead member having a contoured surface along a portion of its outer circumference, and defining an annulus provided between the inner and outer wellhead members;
• a seal assembly in the annulus, having wickers on an outer surface sealingly engagable with the wickers on the outer wellhead member inner surface to thereby form a wicker seal and having overlays on an inner surface in sealing engagement with the inner wellhead member, an annular channel provided in the seal assembly;
• an energizing ring insertable into the channel to provide a force for urging the inner and outer surfaces into respective engagement with the inner and outer wellhead members;
• and
• a radially contractable lockdown member supported on a portion of the seal assembly and engaged by the cam surface, wherein movement of the energizing ring as it is inserted into the channel, pushes the lockdown member into engagement with the contoured surface on the inner wellhead member.