Currents in Brazil’s far North Stop Drilling
Brazilian national operator Petrobras had a scare with one of its drilling rigs off the coast of the state of Amapé, the northernmost state in Brazil, where the mouth of the Amazon River is located. Although the drilling rig did not completely loose from its mooring anchors, it did tip to one side in such a way that Petrobras was forced to abandon the well. This accident occurred in December 2012 but as yet the well continues plugged.
With this development Petrobras was forced to ask the national O&G regulator ANP (National Petroleum Agency) for a longer deadline to be approved for its exploratory plan in the block located at the Amapá coast, in order to better study the very strong currents that occur in this region.
Sources pegged the losses at around US$ 150 million, this has not been confirmed by the national operator.
The problem with the drill rig in Amapá also worries the ANP as the region, officially known as part of the equatorial margin, will have block negotiated during the long awaited 11th round of tendering. The studies of the currents may take over a year to complete, directly affecting future production plans.
Although the mooring anchors on the drill rig did not actually come loose, they did however drag on the bottom causing the rig to tilt dangerously and also caused the wellhead to tilt during the drilling of the Oiapoque exploratory well, which actually lies right on the border of the northern states of Amapá and Pará.
Specialists explained that the force of the current was such that the risers were torn loose and the BOP was also affected, but with no oil spill happening. The rig was dragged around 250 meters by the force of the currents. These same specialists informed that the higher up the equatorial margin the stronger the currents and that these may vary according to depth and also that some of the currents are affected by the Amazon River, making them very strong indeed. Petrobras has confirmed that it will only resume drilling once it has a better grasp on these currents and feel safe about the mooring system.
The Oiapoque exploratory well is located 138 km from the coast of Amapá at a depth of 150 meters.
Claudio Paschoa is Marine Technology Reporter's correspondent in Brazil.