Abstract: A pressure energised seal for a wellhead, in particular, provides a seal of an annulus between an inner wellhead casing member and an outer wellhead casing member. The wellhead incorporates a clamping arrangement whereby the outer member is arranged to be deflected radially inwardly in order to grip and secure the inner member within the bore of the outer member. Also, a seal for use in such a clamping arrangement. In particular, the seal includes a sealing lip which locates within a groove provided in the outer clamping surface of the inner member. A seal is activated and created as the outer member is clamped inwardly since this causes the outer member to compress the inner member and to reduce the diameter of the inner member. Also, a well and a method of sealing an annulus in a well.

Abstract: A crown plug for a tree of an oil/gas well/wellhead has a securement arrangement for securing the crown plug within the tree. The main body of the crown plug comprises a solid body creating the barrier within the production bore. The solid body creates a robust, strong and reliable barrier. The crown plug is retained within the outer member through inward distortion which secures the crown plug. The securement arrangement arises from an inward radial force that distorts the outer member inwardly to grip a component located within the outer member. The outer member elastically deforms and the outer member returns to a released position once the clamping force is released. Two concentric oppositely arranged tapered surfaces move axially to create the inwardly directed force. The clamping force and the solid body together provide an improved crown plug which is easy and reliable to operate.

Abstract: A pressure energised seal for a wellhead, in particular, provides a seal of an annulus between an inner wellhead casing member and an outer wellhead casing member. The wellhead incorporates a clamping arrangement whereby the outer member is arranged to be deflected radially inwardly in order to grip and secure the inner member within the bore of the outer member. Also, a seal for use in such a clamping arrangement. In particular, the seal includes a sealing lip which locates within a groove provided in the outer clamping surface of the inner member. A seal is activated and created as the outer member is clamped inwardly since this causes the outer member to compress the inner member and to reduce the diameter of the inner member. Also, a well and a method of sealing an annulus in a well.