Well Completion

The well is “completed” when a steel pipe, called casing, is lowered, drilled, and cemented. The pipe is then drilled in the desired area, creating a path for the natural gas into the rock. Then another steel pipe, called a gas tubing, is inserted into the well, allowing natural gas to flow from a depth of 2,500 meters below the sea floor.

Collect

At the bottom of the sea, natural gas is collected in underwater collection systems from several wells. From here the natural gas is piped through a pipeline’s grid to the onshore LNG facility. Subsea systems are designed with underwater controls to regulate well flow and provide a safe and reliable means of shutting down.

Processing & liquefaction

At the onshore installation of the Mozambique LNG Project, natural gas will be received, pre-treated, and liquefied. During pre-treatment, the natural gas will pass through a series of pipelines and vessels designed to remove water and hydrocarbon liquids, along with any impurities, thus ensuring high-quality natural gas.

After the treatment and conditioning of the natural gas is treated, the gas flow is directed to a liquefaction unit, where it will go through several stages of refrigeration. By cooling the gas to approximately -162°C, it condenses into a clear, colorless, non-toxic liquid. The liquefaction process reduces the gas volume by 600 times, making it easier to store and transport.

LNG Storage

Once liquefied, the LNG is delivered into large, specially designed, sealed, and non-pressurized tanks, where it is stored, at –162°C, until ready for transport. All tanks for the Mozambique LNG Project will follow strict industry standards in terms of total containment. Full containment tanks generally consist of a primary container of 9% nickel steel, known for its excellent strength and durability at cryogenic temperatures.

Around this container, there is a pre-stressed concrete structure that provides primary vapor containment and secondary liquid containment. If necessary, the external tank can also contain the liquid and provide a safe and controlled release of the vapor. Additionally, storage facilities are equipped with advanced safety systems to monitor pressures, detect problems early and quickly activate an emergency shutdown if necessary.

LNG shipping and transportation

From the storage tanks, the LNG will be transported via insulated pipelines to a nearby export dock, where it will be loaded onto purpose-built LNG vessels.

LNG ships come in various sizes, shapes, and models. There is no “one size fits all”. Each project develops its own ship size. A key feature of double-hulled vessels is the presence of insulated containment tanks, keeping the LNG liquid for sea travel to markets and consumers around the world. Once loaded onto the ship, it keeps the LNG in a liquid state during its journey for delivery to global markets. The LNG vessel acts as the floating “pipeline”, carrying the LNG to different destinations around the world. Travel time from Mozambique to terminals in northern India could take around 7 days, while delivery of LNG cargo to certain Japanese markets could take approximately 17 days. Upon reaching the destination, the LNG is unloaded at the buyer’s regasification terminal. The LNG is then transferred to storage tanks and goes through a vaporization process, where it is heated to convert back into natural gas. This clean- natural gas is then delivered to end users for energy supply.

Preparation for LNG production

After a well is successfully drilled and commercial quantities of natural gas are confirmed through appraisal activities, the development phase begins. This phase generally involves preparing the wells for production.

Due to the location of the natural gas discovered in Area 1 offshore Mozambique, which is approximately 40 kilometers from the coast and in water depths of approximately 1,600 meters, it is necessary to use specially designed equipment to produce, collect, process, and transport the natural gas to onshore facilities for processing.