The Ashburton to Onslow Pipeline System (also known as the Onslow Lateral or AOGP) is a transmission pipeline system located in north-west Western Australia. It is owned by DDG, a subsidiary of the Australian Gas Infrastructure Group (AGIG). AGIG is owned by various consortia of Hong Kong-based entities listed on the Hong Kong Stock Exchange. The consortia include CK Asset Holdings Ltd (CKA), CK Infrastructure Holdings Ltd (CKI), Power Assets Holdings Ltd (PAH) and CK Hutchison Holdings Ltd (CKH).
The system is 110 km in total, and combines the refurbished 87 km Tubridgi Pipeline System (TPS) with a new 30 km Onslow Lateral. It delivers 10 TJ/day.
The TPS runs parallel from the Tubridgi gas processing facility to Compressor Station 2 on the Dampier to Bunbury Natural Gas Pipeline (DBNGP), while the Onslow Lateral connects Compressor Station 2 on the DBNGP to a new Horizon Power operated Onslow Power Station. Horizon Power is the foundation shipper for the pipeline system.
The Ashburton to Onslow Gas Pipeline System is currently a non-scheme pipeline system, and is subject to the access regime for non-scheme pipelines under Chapter 6A of the NGL and Part 23 of the NGR. On 20 June 2023, the ERAWA granted a five year category 3 exemption under Part 23 to the Ashburton Onslow Gas Pipeline.
The Onslow Lateral was completed in June 2016.