Bayu-Undan

Bayu-Undan. It is a major gas and condensate field located in the Timor Sea, within the Joint Petroleum Development Area (JPDA) jointly administered by Timor-Leste and Australia. The field was a cornerstone of Timor-Leste's economy for nearly two decades, providing critical revenue through the export of liquefied natural gas (LNG) and condensate. Operated by Santos Ltd following its acquisition from ConocoPhillips, the field's production life has now concluded, shifting focus to a major carbon capture and storage project.

Overview

The Bayu-Undan field resides in the Timor Sea, approximately 500 kilometers northwest of Darwin, Australia, and 250 kilometers southeast of Timor-Leste. It falls within the JPDA 03-13 production sharing contract area, governed by the Timor Sea Treaty between Timor-Leste and Australia. Discovered in 1995 by a consortium led by Phillips Petroleum, the field was developed in multiple phases, initially focusing on condensate and liquefied petroleum gas (LPG) extraction before the full gas phase commenced. The infrastructure ultimately included a network of subsea wells connected to a central floating production, storage and offloading (FPSO) vessel and a 500-kilometer pipeline transporting gas to the Darwin LNG facility. The field's development and operation involved major international firms including ConocoPhillips, Santos Ltd, Eni, and INPEX, and its revenues were vital for the Petroleum Fund of Timor-Leste.

Development and production

The development of the field proceeded in distinct stages, managed initially by Phillips Petroleum and later ConocoPhillips. The first phase, beginning in 2004, targeted the extraction and offshore processing of condensate and liquefied petroleum gas (LPG) using the Bayu-Undan FPSO, with products shipped directly to market. The subsequent, larger gas phase became operational in 2006, involving the construction of the 500-kilometer Bayu-Undan to Darwin Pipeline to transport dry gas to the Darwin LNG plant operated by ConocoPhillips in Wickham Point. At its peak, the Darwin LNG facility, supplied solely by this field, produced approximately 3.7 million tonnes per annum of liquefied natural gas (LNG) for export, primarily to customers in Japan such as Tokyo Gas and Tokyo Electric Power Company. Production from the gas field declined naturally over time, with the final condensate shipment occurring in 2019 and liquefied natural gas production ceasing in 2022.

Gas field characteristics

Geologically, the reservoir is located in the Sahul Platform region of the Timor Sea, containing hydrocarbons within the Plover Formation sandstone. The structure is a large anticline with significant vertical closure, holding an estimated original recoverable resource of 3.4 trillion cubic feet of dry gas and approximately 400 million barrels of condensate and liquefied petroleum gas (LPG). The natural gas is notably lean, with a high methane content and very low levels of impurities like carbon dioxide and hydrogen sulfide, which simplified processing at both the Bayu-Undan FPSO and the Darwin LNG plant. The overlying Timor Sea is relatively shallow at the site, with water depths around 80 meters, facilitating the use of a fixed jacket platform for gas compression alongside the floating production, storage and offloading (FPSO) vessel.

Economic and contractual aspects

The field was governed by the Timor Sea Treaty, which established the Joint Petroleum Development Area (JPDA) and stipulated a 90:10 revenue split in favor of Timor-Leste for resources within the zone. The development was executed under the JPDA 03-13 production sharing contract, with the Petroleum Fund of Timor-Leste being the primary beneficiary of state revenues, which totaled billions of dollars over the project's life. Key contractual partners and equity holders throughout its life included ConocoPhillips (as initial operator), Santos Ltd (which became operator in 2020), Eni, INPEX, Tokyo Gas, and Tokyo Electric Power Company. The liquefied natural gas (LNG) was sold under long-term contracts primarily to Japanese utilities, providing a stable income stream, while condensate was traded on the spot market in Asia.

Decommissioning and future

With hydrocarbon production ended, the focus has shifted to decommissioning and repurposing the extensive infrastructure. The current operator, Santos Ltd, is leading a major project to convert the depleted gas field into one of the largest carbon capture and storage (CCS) hubs in the Asia-Pacific region, known as the Bayu-Undan CCS Project. This initiative plans to inject carbon dioxide captured from industrial facilities in Asia, particularly in Japan and Singapore, into the former reservoir. The decommissioning scope includes the safe removal of the Bayu-Undan FPSO, the fixed jacket platform, and associated subsea equipment, with the Bayu-Undan to Darwin Pipeline being considered for potential reuse in the CCS scheme. This transition positions the asset as a critical piece of regional climate change mitigation infrastructure under agreements like the Asia CCUS Network.

Category:Gas fields in the Timor Sea Category:Energy in Timor-Leste Category:Energy in Australia