Petroleum Safety Authority Norway : Investigation report on Gjøa condensate leak and notice of order

The Petroleum Safety Authority Norway (PSA) has completed its investigation of a condensate leak on the Gjøa field on 21 June 2017. This identified breaches of the regulations, and notice of an order has been given to operator Engie E & P Norge AS (Engie).

The Gjøa field lies in the North Sea, about 50 kilometres north-east of Troll and 65 kilometres south-west of Florø. It has been developed with four subsea templates and a satellite well tied back to a semi-submersible production and processing facility. The field came on stream in 2010. Engie is the operator.

The leak occurred in the process module on the Gjøa facility at 20.01 on 21 June. This incident led to gas detection, a general alarm, automatic shutdown of the process plant, pressure blowdown and mustering in accordance with the alarm instructions.

Engie has estimated the leak rate at 1.06kg/s and the total quantity leaked as about 1.25m³. Analyses show that the fluid consisted largely of produced water with small quantities of hydrocarbons in the form of gas and condensate. The condensate did not ignite during the incident. The leak was halted after about 30 minutes.

The direct cause of the leak was a fatigue fracture in a weld on a ½-inch pipe nozzle installed on a condensate pump connected to the gas recompression system.

In connection with the emergency shutdown, it was registered that an emergency shutdown valve (ESV) upstream from the leak site failed to close.

The emergency response command on the facility decided to evacuate 19 people to land. There were 49 personnel on board (POB) before the evacuation. The position on Gjøa was normalised at 22.09.

In its investigation of the incident, the PSA has found that Engie's maintenance of the ESVs with associated actuators has been inadequate. These problems have been known over a long period, but not dealt with.

The investigation has identified nonconformities from the regulations in the following areas:

• barriers and the barrier management system
• management and maintenance system
• responding to vibration
• organisation and management.

In addition, an improvement point has been identified related to:

• carcinogenic and mutagenic chemicals.

On the basis of the investigation's findings, Engiehas been given notice of the following order.

Pursuant to section 69 of the framework regulations on administrative decisions, see section 5 of the management regulations on barriers, Engie is ordered to take the necessary measures to ensure that safety-critical equipment is operated, tested and maintained in a way which ensures the performance of the barriers at all times. See chapter 7.1 .1 in the report.

The deadline for compliance with this order is set to 2 February 2018. We must be informed when the order has been complied with.

Explanation of the terms 'order' and 'notice of order'
An order is an administrative decision made pursuant to the regulations. Before the PSA issues an order, it generally sends a 'notice of order' to the affected companies.

A notice of order is neither an instrument nor a notice of sanctions, but a step in the PSA's administrative process in which it requests the party to assess the factual basis. The notice is only a first step before an administrative decision is made.

An order is a strongly preventive instrument which is legally binding on the recipient.