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Downtime plagues pivotal Newfoundland offshore well
By Gary Park For Petroleum News
What was destined to be one of the most expensive, deepest and most challenging offshore exploratory wells in Canadian history is living up to expectations.
With the future of Newfoundland’s industry riding heavily on the outcome, the Chevron et al Great Barasway F-66 well has been slowed by some operational problems with the semi-submersible rig Eirik Raude.
Spudded in mid-August, and with completion hoped for within six months at a cost of about C$140 million, Great Barasway has already fallen a month behind the timetable after operational downtime in late January that extended to a second rig problem and finally a halt to drilling on Feb. 26 while the deepwater rig, which moves under its own power to a maximum of 7 knots, moved to the Marystown shipyard in Newfoundland for repairs.
It headed back to the drill site March 15 to resume operations.
Because of F-66’s tight hole status, operator Chevron Canada could not say what progress the well had made towards its targeted subsea depth of 24,300 feet, what challenges it has encountered or how long it might take to complete operations.
The partners are Chevron 50 percent, Shell Canada 20 percent (after negotiating a farm-in two years ago) and sister companies Imperial Oil and ExxonMobil Canada, each with 15 percent.
The Exploration License 1076 being drilled carries a work bid of C$181.3 million which is effective until Jan. 15, 2013.
Orphan could hold four oil pools In 2003, Chevron, ExxonMobil and Imperial committed C$628 million in spending for eight parcels covering 5.25 million acres in Newfoundland’s Orphan basin, which independent surveys have indicated could hold four oil pools each containing more than the Hibernia field’s original 884 million barrels.
But the F-66 well is being drilled in 7,900 feet of water, 24 times deeper than the average of those drilled at the currently producing Hibernia, Terra Nova and White Rose fields in the Jeanne d’Arc sub-basin.
The Orphan basin poses some of the wildest conditions anywhere in the world. From 1974 to 1982 six wells were drilled in the region without posting a discovery, although two of the wells showed traces of natural gas.
The Eirik Raude, completed in 2002, which is under contract to ExxonMobil for Great Barasway, has drilled three previous wells in offshore Canadian waters.
The long-term future of offshore Newfoundland, where exploration has tapered off, is closely tied to a breakthrough in the Orphan basin.
Unhappily for the partners and the Norwegian-based rig owner Ocean Rig, it fell behind schedule in late January when the top drive main shaft broke. That was quickly repaired only to be followed by some broken tensioner wires that were also replaced in short order.
But Ocean Rig said both setbacks were compounded by “severe weather conditions.”
When a small crack in one of the bracings caused some water leakage, Ocean Rig chose to take the rig out of service Feb. 26 and move it to Marystown.
It estimates the combined loss of revenue and cost of repairs at US$10 million.
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