Saudi Aramco is shortlisting bidders for a contract to install pipelines as part of its estimated $4.5bn megaproject to expand gas processing capacity at Haradh and Hawiyah.

The pipelines tender, which comprises package five of the project, is expected to be floated in May after Aramco invites companies to bid on the four larger processing plant packages.

The scope of the package, named Freeflow Pipelines of Haradh Gas Increment Programme, includes:

Expansion and modifications of the Haradh area piping network and remote headers in the Midrakah fields, including the construction of a new remote header

Construction of a new valve station and liquid separation station as well as tie-ins to the nearby South Haradh gas gathering manifold

Construction of a single 36” transmission pipeline from Midrikah remote header B to the new vale station and two 36” transmission pipelines from the valve station to the Hawiyah gas plant.

The package is an In-Kingdom Lump Sum procure and build contract. Aramco aims to award the contract by August 2017 and start construction in September.

The project will build new gas compression plants at Haradh and expand the gas plant at Hawiyah. The proposed facilities will have the capacity to process more than 1 billion cubic feet a day (cf/d) of additional gas produced at the Ghawar onshore oil field – the largest in the world.

At least 14 companies are thought to have submitted pre-qualification documents for packages 1-4, which are expected to be tendered later in March.