With depressed oil markets and restrictions on project funding and the sanctioning of developments, there is an acute focus on identifying areas where capital and operational expenditure can be reduced, whilst maintaining capability and safety. One area of focus is on the conveyance method, namely the well access structure, "the Rig". With rig costs well construction and de-construction operations typically accounting for over 50% of the project cost base, it has been identified as an area where the introduction of new technology has the potential to significantly reduce overall project costs.
The market adoption of alternative technologies, such as the "Rigless" approach is in its infancy in the European market, however regions such as the Gulf of Mexico and Asia Pacific have successful track records in the implementation of technologies in completions, intervention and abandonment projects.
The paper describes alternative facilitating technology, focused on providing the required level of specification for the operations, with a reduction in the base cost of the technology, namely Rigless operations. The core technology is presented, with key facilitators. The application of the technology is presented in three case studies, each demonstrating the specific challenges of the operations and the novel solutions engineered to address these challenges.
The detailed engineering presented in the case studies, allied to FEED (front end engineering design) demonstrate the potential savings that can be achieved through the core technologies, and bespoke interfacing of them to client requirements.
Case study 1 presents a full abandonment campaign undertaken with a Supermajor in the Gulf of Mexico on a platform with significant structural impairment after hurricane damage.
Case study 2 presents a full abandonment campaign undertaken with a Supermajor in the Gulf of Mexico with a Pulling and Jacking Unit. This included temporary partial abandoned and Shut in wells, allied to sustained casing pressure and re-entry issues.
