The gas will be supplied by Shell in LNG carriers from Qatar. On arrival at the LNG terminal, the LNG carrier will berth alongside the FSRU and will discharge its cargo of LNG into the unit. The LNG will be repressurised into natural gas and delivered via the LNG jetty’s high pressure loading arms into the Terminal pipework infrastructure and through the gas metering system on its way to the FAJR transmission pipeline.
The FSRU, which is being provided by Golar, is currently undergoing sea trials in Singapore. The vessel is due to arrive at the LNG terminal in mid-April in order to allow commissioning and testing of the facility.
“That vessel is expected to arrive with a commissioning cargo of LNG and will then be made ‘cold’ to facilitate the hot commissioning stage of the works. They call this ‘coming hot’,” said McDonagh. “Prior to this stage, our task is to ensure that the LNG Terminal process equipment and systems have been fully commissioned. This includes ensuring the gas metering system.”
The JV has designed and built all the marine structures in order to accommodate the combination of the FSRU and LNG carriers. The marine works include four mooring dolphins, two breasting dolphins and a loading platform.
There is also an approach trestle that provides the access to the loading platform from land. The 106m trestle is supported by seven piled supports constructed of pairs of raker piles with reinforced concrete headstocks, prestressed concrete beams, precast concrete diaphragm walls and precast concrete roadway slabs.
“The southern part of the approach trestle is a road with the northern section being dedicated to the services such as the 24-inch gas pipeline, the fire main, compressed airline, nitrogen line and power, lighting and I&C cabling. The road can handle the ten-tonne mobile crane that is required to drive out onto the loading platform to do any maintenance on the loading arms or other heavy lift activities,” said McDonagh.
“The landside part of the trestle is a ramp that comes down over piled headstocks onto land and then ends in an abutment. It is effectively a bridge.”
The pipeline transitions from the north side of the road to the south side by dropping down into the abutment structure, passing underneath the road and then returning up and over the south side of the abutment, enabling it to run parallel to the main road until it hits the process area.
The process area contains the gas metering/chromatograph, HIPPS and ESD systems which provide the required metering and safety shutdown capabilities.
Downstream of the process area the pipeline goes underground and turns south to run alongside the public road to the tie in point with the FAJR transmission pipeline. These works have been extended by 120m due to a relocation of the tie in point to better suit the FAJR operations.
The installation of the buried section of the pipeline has necessitated hand digging along the majority of the route in order to navigate and safeguard the myriad of live existing services that are crammed into the available route.
Marine structural work started with the piling works on 19 July last year and the last of the concreting operation to the structures took place on 3 January this year. The work was completed some two months ahead of schedule.
“This has been a major achievement considering the complexity of the piling, where 90 of the 98 structures piles are raking piles, raking in different directions and the piles being up to 78m in length, requiring splicing over water,” said McDonagh.
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