LNG TANGGUH EXPANSION PROJECT - TRAIN 3

The project

In 1994, a large natural gas field was discovered in the bay of the province of West Papua, about 3,000 km from Jakarta.

The reserves are calculated at about one million tons of LNG (liquefied natural gas) per year for 20 years. Indonesian President Suharto named the gas field “Tangguh” (“mighty”).

The Saipem project involves the onshore construction of a liquefaction plant with a capacity of 3.8 MTPA (million tons per year), ancillary services, a LNG jetty (equipped for gas liquefaction and transport by sea) and related infrastructure. 

Project impact

The project allows Indonesia to maintain a significant share of the world LNG market, offsetting the progressive elimination of the Arun terminal in Sumatra, whose reserves are largely depleted.

Furthermore, it guarantees an important share for exports to other Asian countries, mainly China, South Korea and Japan.

An extraordinary project

The Tangguh project presents a number of challenges. Following the withdrawal of the main construction partner from the consortium, Saipem became the project leader in 2018. At the request of the client, Saipem developed a new execution strategy that eliminates the main factors for delays and costs, including: 

• the difficulty for ships to reach the site due to insufficient dredging of the canals; 

• interference with existing plants in operation; 

• the performance of local contractors imposed by stringent local content conditions; 

• the delayed availability of some facilities. 

The site is a classic example of a remote area: far away from everything, and very difficult to reach due to the lack of basic infrastructure. Each trip to the construction site involves considerable time, several flights and, lastly, a sea crossing. With its logistical challenges – not within everyone’s grasp – the success of the Tangguh project is an emblematic case of the experience and extraordinary ingenuity of Saipem, which knows how to transform engineering and design restrictions into creative ideas. 

Technological challenges

The project’s first technological challenge was the composition of the feed gases, rich in acid gas components, with up to 15% CO2, more than 1% H2S, and mercaptans. This required advanced treatment, such as acid gas removal and acid gas incineration, as well as a special molecular sieve design.

The new plant had to be integrated into an existing facility with two LNG trains in operation, with appropriate management of the necessary connections and engineering. The design, checking and integration of the steam and power systems proved to be a demanding technological challenge that required complex dynamics studies. 

Also of note is the innovative arrangement of the new LNG train, which combines the main refrigerant compression areas into a single common structure parallel to the main rack.

This arrangement posed new challenges related to hot air recirculation and air coolers, which were faced through computational fluid dynamics (CFD) studies and 3D modelling.