Norwegian safety regulators are still investigating the dangers that could persist after a well-intervention vessel collided with part of the 230,000-barrel-a-day Ekofisk complex in the North Sea on June 4th, 2009.

The accident probe at the ConocoPhillips-operated platform aims to secure the safety of the unmanned platform “before it returns to operation or is removed”, a statement from the Petroleum Safety Authority said Friday.

“It’s too early to answer (the PSA hint of possible removal),” ConocoPhillips information advisor Tore Falck told Scandoil.com, after safety regulators sent out their updated report. He also said Schlumberger experts were on-hand, which appeared to confirm well-bore damage.

Some 23,000 barrels of oil production are reportedly affected by the ensuing platform shut-down, a number still unconfirmed.

The PSA told Scandoil.com that photographs revealed heavy damage to the platform and to the Big Orange XVIII well-intervention vessel. Now, operational documents are being scrutinized in what is becoming a “very complex” investigation that could end with local police issuing a big fine.

The impact of the drifting Big Orange “caused damage both to the structure, bridge and well equipment” on the platform and ship, the PSA report said. It added that a “major accident” was only narrowly avoided: Big Orange was heading toward another platform, 2/4-X, when engine breakdown — curse of the shipping industry — caused the hulking ship to drift.

Only the Ulstein design’s bow thrusters prevented collision with 2/4-X and 2/4-C. Power to those thrusters, however, was lost “while passing under the bridge between these installations”; then came the collision with Conoco’s “Whiskey” platform which forced the shut-down of production platform 2/4 A.

ConocoPhillips has tauted its high-tech electronic tracking of all Greater Ekofisk area shipping from shore-based control rooms. While even ships manifests are monitored in real-time from shore, it’s not clear if sensor signals — the many “electronic tags” behind remote operations — played a role.

“That’s something the investigation must look into,” Falck said.

The captains of two well-intervention ships have, in the past year, expressed for Scandoil.com their very human nervousness at the well-intervention equipment on board the vessels they command. Such captains are now a highly-educated breed, and some new ships have two captains — one for oilfield operations.

Ekfofisk, meanwhile, is Norway’s oldest oilfield, and the Big Orange is about 25 years old, or about the age when some ships are retired.

A major, multi-year overhaul of the Ekofisk field platform is in the works with new structures being built and old ones being decommissioned. A project plan is expected by year-end 2009.

Tags: ConocoPhillips, Ekofisk field