Head of Mooring Analysis and Offshore Department
11:45 - 12:15
Wednesday, 18 September 2019
T1.4 2nd Feasibility Study for a FLNG-Barge Instalation in Bahia Blanca (Argentina)
This paper presents the nautical studies performed to analyze the feasibility of the STS LNG load operations from the shore installations to a receiving LNG carrier, through the mooring of a FLNG barge (EXMAR) at Mega terminal (YPF) in Bahía Blanca (Argentina).
Different nautical studies have been performed to assess the feasibility of load operations and to define the mooring systems, both for the FLNG barge and for the receiving LNG carrier. This way, the safety of the operations can be guaranteed from the point of view of the mooring conditions of both ships in different scenarios. The barge “Tango FLNG” (TFLNG) will be permanently moored at the terminal. The TFLNG will receive Compressed Natural Gas (CNG) from the shore facilities, will perform the liquefaction process and will supply Liquefied Natural Gas (LNG) to the LNG carrier using flexible hoses. The LNGC will be moored ship-to-ship to the TFLNG unit to load the cargo.
Based on the set of different analyses performed, improvements related to infrastructures and mooring equipment at Mega Company Terminal (YPF) and TFLNG (EXMAR) have been proposed as necessary for an adequate mooring of the vessels.
Firstly, a Geometric Compatibility Study has been developed to detect any possible incompatibility between the TFLNG barge moored at the Mega Company Terminal in the Port of Bahía Blanca and the receiving LNG carriers.
The analysis of the geometric compatibility of the FLNG barge moored alone in the terminal, and of a fleet of LNGC moored alongside the barge to carry out ship-to-ship cargo transfer operations, is developed. This study covers the load/unload and mooring equipment, both onboard and onshore, and any geometrical incompatibility between the jetty and the barge.
A dynamic behaviour study ("Dynamic Mooring Analysis" DMA) has been also carried out to analyze the feasibility of installing the TFLNG barge moored at the Mega Company Terminal in the Port of Bahía Blanca.
The analysis of the mooring conditions of the CFLNG moored alone as well as combined with the design ship, a 150 900 m3 LNGC moored ship-to-ship, has been developed by means of time domain simulations using a numerical model in order to establish the survival and operating limits.
This analysis has considered the local metocean conditions at Bahía Blanca port. This includes the analysis of extreme conditions for the TFLNG, and the analysis of a set of operational conditions for both, TFLNG moored alone and TFLNG – LNGC moored STS.
This way, operational and permanence limits have been derived for the load operations (both TFLNG alone and STS load transfer operations).
A third study ("Passing Ships") has been carried out to analyze the influence that passing vessels in the vicinity of the terminal may have on the availability of installing the TFLNG barge moored at the Mega Company Terminal in the Port of Bahía Blanca.
Different vessels calling or leaving terminals located upriver MEGA berth, different passing speeds and distances have been analyzed in order to establish the recommended limits.