Group outside building

Asset protection and major accident prevention

Our procedures are designed to protect the integrity of our assets and help ensure all our operations are carried out effectively and safely.

All our operations comply with national and relevant international legislation. If there is no local legislation, our default position is to adopt industry good practice normally based on UK regulatory standards and International Association of Oil & Gas Producers (IOGP) guidance. These have also been used in the formulation of the Cairn Corporate Responsibility (CR) Standard Operating Procedures as part of the CR Management System.

Prior to any work beginning, we undertake comprehensive audits of all the vessels and drilling rigs our contractors intend to use in our operations. These include compliance to standards and a review of their monitoring, inspection and maintenance procedures; and any shortfalls are reported and remedial actions followed up.

As part of our commitment to safety and the prevention of major accidents or hydrocarbon spills, we actively support and participate in initiatives established by IOGP (see Major accident and spill prevention).

Safe drilling

Cairn’s reputation for responsible exploration is underpinned by a rigorous approach to well design and well control. All our wells are engineered to the highest industry standards and are designed to comply fully with the requirements of the Cairn Well Engineering and Construction (WEC) and Corporate Risk Management (CRM) systems. Safe drilling is dependent on the development and implementation of multiple safety barriers, which are designed into our drilling programmes and verified by a series of rigorous internal and external WEC assurance processes.

  • Design – our wells are designed and assured to a level that exceeds requirements for the expected characteristics of the geological formations to be encountered. We apply our well design standards to ensure the appropriate materials are used and installation methods conform to recognised good industry standards. We also select drilling fluids to maintain well integrity and minimise impact on the environment.
  • Primary well control – we apply a dual barrier approach during drilling activities. This involves control measures designed to maintain fluids in the wellbore, including drilling-hole pressure evaluation and management, kick detection, kick tolerance management, fluid management, cementing practices, blow-out preventer (BOP) system testing and assurance. Testing of a BOP system is rigorous and conducted routinely on a defined schedule to ensure it remains functional. In the event of unsuccessful tests, we make safe the well and cease drilling until the problem is found and resolved, which can result in substantial lost time and cost. Despite this, we do not recommence drilling until completion of any required remedial work and, if necessary, specialist support to assure the BOP system is fully functional.
  • Secondary well control – this includes measures to prevent wellbore fluids escaping from the well, using a BOP. The BOP, which is usually installed on the wellhead at the seabed, is made up of a series of hydraulically operated rams and can be operated in an emergency from the rig or via the backup remotely operated vehicle (ROV) on board a standby vessel that remains with the rig. The BOP is rated for pressures significantly in excess of those expected to be encountered in the exploration well.
  • Tertiary well control – these measures provide a third line of defence when formations cannot be controlled by primary and secondary measures, and cover well control options such as drilling of a relief well and use of a capping device.

Diagram showing well control

Well engineering and construction internal and external assurance processes

Internal External
Cairn Project Delivery Process (PDP) gate reviews Major hazard assessment
Project risk register In-house
Corporate risk management review In-house
Well Engineering and Construction Team competency assessment Regulator and partner reviews
Inspection, testing, acceptance and induction of drilling rigs and vessels Independent expert review of critical equipment and systems
Daily operational reviews Major Hazard Assessment (MHA)

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