In 1991 Crawford became the first UK North Sea field to be abandoned. Novel approaches were employed both in the design of the development and in the methods used to abandon the wells and facilities. These, together with detailed planning and early involvement with the UK authorities, contributed to the success of the abandonment operations which were completed under budget and without injury. Most of the equipment recovered was in suitable condition for re-use.

Well abandonment and subsea facilities removal operations were conducted concurrently. The Yatzy, a dynamically positioned (DP) semi submersible drilling rig, was used to abandon the wells. The use of a dynamically positioned rig resulted in flexibility in the sequencing of operations and time and cost savings on rig moves. It was able to work very closely with the dive support vessel (DSV) Stena Constructor used to recover the subsea facilities and to assist with re-entering the subsea wells.

You can access this article if you purchase or spend a download.