Mumbai High tender for OBC 'high resolution' 3D

Vol 15, PW 3 (11 Aug 11) Exploration & Production

ONGC wants to shoot ‘high-resolution’ seismic at its producing Mumbai High oil and gasfield so it can reassess the field’s remaining reserves.

ONGC announced the eagerly-awaited $120m tender to shoot 1500-sq km 3D using Ocean Bottom Cable (OBC) technology in a tender published on July 22. “This is one of the largest and most eagerly awaited ONGC seismic tenders this year,” says a likely bidder.

“It’s going to be a long and complex job because ONGC wants to use the OBC method.” Normally, he explains, seismic survey ships trail ‘streamers’ and pull cables and sensors across a specific area.

But the OBC method uses cables and sensors spread along the seabed to get high resolution images of the ‘sub-surface. “Cables and sensors on the seabed can easily get washed away during rough weather,” we learn.

“This is what makes OBC so challenging.” It is expected that the selected contractor could take more than two and a half years to complete the high resolution seismic job for ONGC.

“At least two seasons are needed for this,” says an industry source. “Another eight months is needed to process and interpret this data so the job will be completed only by the middle of 2013.

” ONGC, he adds, is also likely to soon invite bids from companies that can acquire 375-sq km of similar high resolution seismic data at its producing Heera oil and gasfield. Only a few companies worldwide are equipped to carry out such surveys, adds an observer.

Among those expected to bid are Paris-headquartered CGGVeritas, Houston-based Geokinetics, Texas-based Global Geophysical, Schlumberger-subsidiary WesternGeco and Norway-based Reservoir Exploration Technology. Interested companies must submit bids by September 23.