Delivering for BLNG, Brunei

Overview
We replaced four main cryogenic heat exchangers, each with a dry weight of approximately 115 tonnes, in a live train and completed ahead of schedule with no lost time safety incidents. We also did preparation work for four major shutdowns. Altogether this is a great example of how our meticulous attention to health and safety, and experience-informed planning and quality management achieves world class results. 

Scope

• Detailed design engineering
• Replace the Main Cryogenic Heat Exchanger (MCHE) in trains 1-4 
• Replacement of certain utilities equipment and two analyser houses
• Replacement of sulfinol regen columns in two trains

Background
The Brunei liquid natural gas (LNG) plant was completed in 1972 and was the first of its kind in the Western Pacific. It pioneered large-scale liquefaction and transportation of natural gas, and ships 6.71 million tonnes of LNG per year. The main cryogenic heat exchangers are the machinery where liquefaction of the gas takes place. Replacing them was part of an extensive programme of improvements at the plant that are designed to extend its life for 60 more years.

Challenges

• First ever MCHE replacement project in the LNG industry
• Extensive and large-scale work on live plant
• Accelerated schedule
       

PSN’s approach

• We introduced our customer to new HSE management systems and performance levels, and new quality management and planning systems
• Nationalisation was a priority. We used mainly Brunei-based contractors and sub-contractors, sharing skills and benefiting the local economy. We also trained local staff, enabling a skills and knowledge transfer
• We completed the front end engineering design, detail engineering, procurement and construction of the project. After replacement of the first two heat exchangers our customer accelerated the programme by three months and we completed the replacement of the last two heat exchangers within the new timeframe
• We were able to install the heat exchangers while the train was in full operation by conducting extensive pre-shutdown activities on the newly installed heat exchangers. The accelerated programme resulted in us performing pre-shutdown activities on two trains simultaneously. We conducted planned shutdowns to tie-in piping and remove existing heat exchangers 
• The train shutdown for the first replacement of a heat exchanger was completed one day ahead of schedule. We then performed a lessons learned exercise that enabled us to reduce the mechanical duration for each subsequent replacement, from 51 days for the first, to 25 days for the last
• Activities were coordinated between our scope of work and our customer’s maintenance activities through an integrated planning team. This ensured that the overall critical path had priority 
• Our site team introduced our work planning system and job cards to measure and control activities taking place on the site. We also used our completions management system to control the quality documentation on the site, which allowed for control and visibility of key activities and ensured that the heat exchangers were handed back in an efficient manner at the end of each shutdown      

Achievements

• Over 2.5 million manhours LTI-free and over 1 year medical treatment case (MTC) free
• The first ever MCHE replacement project undertaken in the LNG industry
• Shutdown works for trains 1, 2 and 3 were completed ahead of the 42-day contract requirement
• All trains were started up without encountering any leaks during the start-up phase