Improved HSEQ and Survey Efficiency Demonstrated with a New Remotely Operated Streamer Cleaning Tool

Barnacle growth on seismic streamers creates noise on the recorded signals. Keeping a low noise level in barnacle areas is challenging to the seismic crews. Frequent workboat trips are required for streamer cleaning. Workboat operations are weather dependent and are considered undesirable from an HSE perspective. In 2007 a purely mechanical and autonomous Streamer Cleaner Unit (SCU) was introduced. The SCU is launched and recovered from the workboat. In 2016 Tonnessen and Skadberg (2016) presented a Remotely Operated Streamer Tool (ROST) capable of launching and recovering SCUs to/from the streamer without the use of a workboat, and which is less dependent on weather. The ROST is operated from a Support vessel. Experiences from four surveys are presented. Operation in high sea states is demonstrated on a survey offshore Namibia and operation in extreme currents demonstrated on another survey east of South Africa. A noise removal method is presented that allows operation of the system while online. The method was first applied on a survey offshore South Africa and later on two surveys offshore Angola. It is demonstrated that work boat hours can be reduced by 70-80%, and a 14 streamer spread can be cleaned twice a week while acquiring seismic.