Conducted in ~1,000 m (3,280 ft) water depth, the survey covered an 8 x 6.13 km grid (5 x 3.81 mi) over three planned exploration wells in the Ex30 Trident block.
JFMS delivered the scope on Lukoil’s behalf in order to comply with a new Romanian environmental law dictating that the company must perform an archaeological clearance survey. This looks to identify any potential archaeological targets, and where none remain, sanctions the area as being clear of any archaeological interest.
The company procured the multi-purpose support vessel Ievoli Cobalt, mobilized with a towed side-scan sonar and sub-bottom profiler solution, together with a work-class ROV, Triton XLX WROV, for visual inspection of targets identified in the sonar data.
According to the company, the survey required it to identify any anomalies with dimensions exceeding 1 m (3 ft) in all axes – using the side-scan sonar to search for surface targets and the sub-bottom profiler to detect sub-surface targets down to a depth of 6 m (20 ft).
The deep-towed solution reduced the operation time to within five days, the company said.
Post-analysis of data revealed no targets of potential archaeological interest, meaning the Romanian authorities are now free to issue an Archaeological Discharge Certificate. Also, Lukoil may now proceed with drilling and construction operations in the field later this year.
Martin Dronfield, director, strategy and business development at JFMS, said: “… This is the first time JFMS has provided a deep-towed subsea survey but the success and acquired expertise means we can expand the survey options we provide.”