A Review of the Nigerian Energy Industry

Riser pipe collapses on Ensco rig off Angola

ensco drillship08 August 2013, News Wires – Rig contractor Ensco has confirmed a report of an incident aboard the drillship Ensco DS-1 in which the crew failed to open the blind shear rams before running the blowout preventer, causing the riser pipe to buckle.

The rig, built in 1999, was drilling for French supermajor Total off Angola in about 4300 feet of water. Total has the drillship under a three-year contract through January of 2016 at a dayrate of around $355,000, according to Ensco’s most recent fleet status report.

Ensco spokeswoman Alice Brink said on Thursday that the incident occurred “several days ago”. The mishap was first reported by maritime news website gCaptain.

According to the website, the crew was lowering the BOP to the wellhead but ran into the the closed blind shear rams at around 3970 feet, causing the hook load to “increase unexpectedly”.

“With the blind shear rams closed, the riser had not been able to fill with water as it was lowered into the ocean, and as the hydrostatic differential continued to build, the pipe collapsed in on itself,” the news site reported, citing an anonymous contributor who provided several pictures of the aftermath.

Brink confirmed the report, adding that “most importantly, no one was injured”.

She said “the cause has been identified” and Ensco is “completing a corrective action plan”

“We expect to be back to work very soon,” she said on Thursday. She provided no timetable or further details.

Total was not immediately available for a request for comment.

According to gCaptain, once the failure had been discovered using ROV cameras, Total continued to lower the BOP to the wellhead and unlatched the Lower Marine Riser Package and brought it to the surface. Total then reportedly replaced the collapsed riser joints.

– Upstream

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