Stena Deep Venture, Gabon
Stena Drilling identified NASeBOP as the ideal solution to support their four well surface BOP drilling campaign in West Africa, providing primary control of a subsea isolation device (SID). The SID provides a means of isolating and disconnecting the riser from the wellhead, allowing the vessel to sail to safety in the event of a blowout, while well control functions were performed by the surface BOP.
Imenco provided the NASeBOP system, which consisted of robust and reliable wireless communications, field tested electronics and a wired modem via umbilical to the SID, to provide fully redundant control during the four well campaign. Umbilical issues led to wireless communication being used as the primary control of the SID for the fourth well. Wireless initiation of an emergency disconnect sequence (EDS) was also possible, although not used. Should the EDS have been initiated, wireless communication enabled the option of SID status to be read post-disconnect, a capability not possible via wired umbilical connection.
NASeBOP provided control of the SID for the duration of the campaign with zero downtime. Umbilical failure was mitigated by wireless communication reliability. Log file analysis highlighted that four wells and > 900 hours operating time saw > 12000 acoustic commands with a command failure rate of 0.82%