Yolla platform; Source: Beach Energy

Beach Energy to develop Trefoil using subsea tiebacks

Oil and gas company Beach Energy has revealed it will be using subsea tiebacks and existing infrastructure to develop its Trefoil project offshore Australia.

Yolla platform; Source: Beach Energy

The T/RL2 license, which includes the Trefoil discovery, is located some 37 kilometres west of the Yolla gas field and platform.

Two wells drilled and intersected the structure during the 2000s. Data provided by Beach Energy claims that it is a low relief, simple anticline structure with net 2P undeveloped reserves of 23.6 mmboe (26.1 mmboe gross).

Beach Energy said in its fiscal year 2021 half-year results presentation that the development of the Trefoil project would utilise the existing Yolla platform infrastructure which currently has around 40 TJ per day of ullage.

Trefoil development schematic; Source: Beach Energy
Trefoil development schematic; Source: Beach Energy

According to Beach, this will extend the life of the Yolla field and defer the abandonment activities of the Yolla platform.

The concept select phase will be completed in the third quarter of the fiscal year 2021 while the company plans to start FEED activities during FY 2021. Final investment decision is set to occur in the first half of the fiscal year 2023.

Net development capex stands between A$500 – 600 million ($388 – 465 million) with a forecast initial rate of return at under 20 per cent and the life of asset at around 15 years.

First gas is set to flow from the fiscal year 2025, subject to necessary approvals. Gas is currently uncontracted and will be sold at East Coast gas market prices.

It is worth noting that Beach Energy agreed to buy Mitsui’s Bass Basin assets meaning that, at closing, Beach will hold 90.25 per cent interest in the Trefoil project.

Namely, the two companies agreed for Beach to buy Mitsui’s 35 per cent interest in the BassGas Project – comprising the onshore Lang Lang Gas plant and Yolla gas field, as well as its 40 per cent interest in the Trefoil development project and surrounding retention leases. The transaction has an effective date of 1 July 2020, with settlement expected during the third quarter of 2021.

To remind, Australia’s National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) approved Beach Energy’s plan for a geophysical and geotechnical seabed assessment on the Trefoil field back in the spring of 2020.