Blowout Well Response: TOTAL Large Scale Exercise Drill in the Gulf of Guinea

Abstract

In March 2019, TOTAL planned and executed the first of its kind Large Scale Exercise (LSE) in Nigeria. Before this operator led LSE, capping equipment had not been deployed in Africa. Since this was the first exercise of the sort to be undertaken in Nigeria, there were several objectives defined at the outset of the exercise: test the entire response chain (logistics, preparation, execution and communication);demonstrate to the Nigerian authorities that a comprehensive and efficient response could be executed in a timely manner; anddocument, record lessons learned and then feed them back to the local affiliate and others to improve future response operations For this exercise, TOTAL deployed its Subsea Emergency Response System (SERS) which was commissioned for construction at the beginning of 2012. Two systems were developed for drilling and production hydrocarbon blowout scenarios. The LSE's focus was to deploy the capping system while also taking the opportunity to simulate pumping dispersant. TOTAL has two SERS's that are stored in Pointe Noire, Congo and Luanda, Angola. Due to the readiness of the system in Congo (recently tested and the appropriate connector installed), it was chosen to be used for the LSE. An abandoned appraisal well was chosen for the exercise due to it being free from subsea infrastructure. The detailed work scope for the LSE was as follows: SERS ○ Controls Distribution Unit (CDU) deployment○ Flying Lead Deployment Frame (FLDF) deployment○ Diverter Spool Assembly (DSA) deployment○ Connection of the Hydraulic Flying Leads (HFL's) and Electric Flying Leads (EFL's)○ Landing the DSA and locking the connector by Remote Operated Vehicle (ROV)○ Performing an Acoustic Communication System (ACS) test Subsea Dispersant Injection (SSDI) ○ Deploying the Hose Deployment Frame (HDF)○ Deploying the routing manifold on Coiled Tubing (CT)○ Connecting all hoses with the ROV○ Simulating pumping dispersant over the well All equipment was successfully deployed and tested with all objectives achieved. The highlights of the operations were as follows: ○ 20 days from Congo SERS equipment loadout until the end of operations○ Approximately 27 hours from OneSubsea (OSS) arrival on the vessel until the DSA was locked on the wellhead○ DSA connector lock and unlock between 4 to 5 minutes○ 52.1 bbls of simulated dispersant pumped within a one hour timeframe