The North-Eastern Offshore (NEO) Pipeline involved the construction of a 94 km, 36 inch diameter natural gas pipeline which originates at a newly-built BHP Billiton gas export platform in the Angostura Field, located off the northeast coast of Trinidad.

The pipeline extends 82.8 km from the platform, crosses the shore at Mayaro Bay for 1.2 km, and continues on land for another 10 km to National Gas Company of Trinidad and Tobago’s (NGC’s) new Abysinnia Accumulator Station at Beachfield.

Historically, the majority of Trinidad and Tobago’s offshore gas supply came from the fields located off the south-eastern coast of Trinidad. After gas fields were identified in the north-eastern acreage, it became necessary to expand the pipeline network to market the newly-discovered gas. The NEO Pipeline now provides access to these north-eastern fields.

The NEO Pipeline project began in 2007, taking four years to complete at a cost of $US450 million dollars. Throughout the project, NGC maintained constant communication with the community, conducting public safety awareness programmes to educate those in the region, as well as frequently holding public consultation meetings for stakeholders.

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All attempts were made to maximise the use of local contractors and service providers for provision of services to support the project, although 8,054 lengths of pipe were imported from India. Once the pipe had been procured, the pipe supplier engaged to have the entire offshore pipe concrete weight coated on the island to prevent underwater current movement as well as to protect it from third party damage.

To minimise the project’s environmental impact, NGC opted to use horizontal directional drilling (HDD) technology to construct the shore crossing at Mayaro. This was conducted on a 24-hour basis until construction was complete. NGC also adopted a “No Net Forest” policy, which states that the company will reforest an area that is equivalent to the area cleared for construction.

The two main challenges encountered during construction related to the Mayaro shore crossing and the pipeline installation. The HDD shore approach posed engineering and construction challenges with respect to drilling and reaming operations, HDD hole condition and stability, pulling loads and buoyancy control of the HDD pipeline section.

The pipeline installation also met with several challenges. Offshore, it was difficult to find a pipelay vessel capable of installing a 36 inch diameter pipeline in open waters, as these are very limited in number. Offshore construction was met with rough sea conditions and excessive undercurrents, so to overcome this, contractors used a large tug boat to pull the vessel forward to provide additional stability during pipelay. Unusually wet weather in a normally dry season also created significant challenges for the construction of the onshore section.

The NEO Pipeline will transport natural gas from new sources in the north east coast marine area to market, and will result in increased reliability of supply to NGC’s Trinidad customers as well as increased revenue for the country. In addition, the pipeline will act as a backup for Tobago; Tobago’s primary north-eastern gas supply will be from a second pipeline NGC is currently constructing; however, if BHP Billiton’s gas export platform is unable to supply gas to Tobago, NGC will be able to supply natural gas from its Beachfield facility via the NEO Pipeline.