Specialised Welding

Project

A drilling contractor in Spain had a requirement to have his BOP refurbished and recertified to meet regulatory standards.

A blowout preventer (BOP) is a large, specialised valve used to seal, control and monitor oil and gas wells to prevent blowouts, the uncontrolled release of crude oil and/or natural gas from wells. Blowout preventers are used on land wells, offshore rigs, and subsea wells.

The contractor contacted the original manufacturer in America for advice on where to send it.  As AJT are an approved repair facility for this manufacturer it made sense on an economic and delivery perspective to have the Spanish contractor send the unit to Aberdeen for repair.

Solution

The repair involved pre-machining the sealing areas in the AJT Tullos workshops and reclaiming the surfaces utilising the latest in rotary head hot wire pulsed gas tungsten arc welding (GTAW) process technology. 

Specialised welding equipment has the ability to control the travel motion of the welding torch through a set of computer-controlled slides, which enabled precise deposition of the weld metal where it was required. 

Due to the advanced technology employed this operation can be carried out in a shorter time than that associated with conventional processes and to more exacting standards, reducing cycle times by up to a third. 

Because the weld metal was not transferred directly across the electric arc like most open arc welding processes, a vast assortment of welding filler metal is available to the welding engineer however in this instance the seal areas were reclaimed using a high strength alloy base material.

The BOP was finally machined and assembled within AJT then returned to the Spanish drilling contractor in a timescale which  allowed him to continue his drilling programme with no loss of time or revenue.

Blowout preventers are critical to the safety of crew, rig and environment, and to the monitoring and maintenance of well integrity, regulations require that BOPs be regularly inspected, tested and refurbished.