ONGC blow-out risk off Mumbai with Aban Ice

Vol 20, PW 21 (13 Jul 17) Exploration & Production
     

ONGC faces the risk of a potential blowout at an exploration well off Mumbai.

PETROWATCH learns Aban Offshore rig Aban Ice ran into trouble at 3pm on June 28 while logging exploration well B_157N#B in water depths of 40 metres where gas shows had been detected. "Apparently the rig lost position and crew were trying to regain position with the Blow Out Preventer (BOP) stack still latched to the wellhead," says a driller.

"Then the riser pipe sheared off." As a result, he adds, the 200-tonne, 11-metre high BOP stack and the 18 ¾-inch diameter wellhead tilted about 70 degrees towards the seabed. Sources say the tilting of the BOP and wellhead towards the seabed has left the 'live' well open with the risk of a blowout - especially since gas shows were recorded while drilling.

Some blame human error. "It is a cardinal rule never to play around with the anchors when the rig is connected to the seabed," says a driller who has worked off Mumbai.

"Standard operating procedure if you have lost position is to first unlatch the rig from the BOP, free the rig from the seabed, regain position, then latch the rig to the BOP again." By July 7 no unusual activity was noticed on the seabed, luckily. "Divers from (ONGC diving support vessel) Samudra Prabha went down to inspect the damage and reported no gas bubbles," we hear.