National Oil and Gas Company, TIS Energy Group, has completed the strategic acquisition of the Sebuku Block from UAE-based energy firm Mubadala Energy, marking a significant step in expanding its upstream oil and gas portfolio in the country.

The transaction, finalized in Singapore on Thursday, July 31, 2025, transfers operator control of the offshore block including the producing Ruby gas field to TIS, which now assumes full responsibility for ongoing operations and future development initiatives.

Previously operated by Mubadala Energy with a 63 percent stake, the Sebuku Block in Makassar Strait, also includes partners TotalEnergies (13.5 percent), Inpex (13.5 percent), and PT Dangsanak Buana Sebuku (10 percent) representing the local government's participating interest. The Ruby field has been producing gas and condensate exclusively since 2013.

With the acquisition, TIS has taken over Mubadala’s operating entity for the Sebuku Production Sharing Contract (PSC) while maintaining collaborative ties with existing partners and local stakeholders.

At the heart of the Sebuku Block is a 312-kilometer subsea pipeline connecting the Ruby field to Senipah, East Kalimantan, a strategic link to the Bontang LNG plant and key onshore processing facilities. The pipeline enables an Infrastructure-Led Exploration (ILX) strategy, which facilitates efficient and cost-effective development of nearby hydrocarbon resources.

“We see Sebuku not just as a producing asset but as a gateway to future hydrocarbon development in eastern Indonesia,” Deputy Managing Director of TIS Energy Group, Colin Soh, said on Thursday.

“The existing infrastructure is world-class. Our task is to unlock its full potential,” he added.

TIS plans to initiate a technical evaluation of production optimization, well workovers, and new drilling opportunities within the block. The company also reiterated its commitment to local capacity building, including enhanced community development programs and workforce training.

“This acquisition goes beyond boosting output. It reflects our long-term belief in delivering sustainable value, supporting energy transition goals, and generating tangible socio-economic benefits for Indonesia,” Soh added.

TIS affirmed its adherence to Indonesia’s regulatory framework, including the Participating Interest (PI) scheme for regional governments as outlined by the upstream oil and gas regulatory task force (SKK Migas).

The company underscored its confidence in Indonesia’s upstream investment climate, viewing the country as a long-term hub for reliable and scalable energy development aligned with national priorities.

Meanwhile, Mubadala Energy clarified that the divestment does not signal a withdrawal from Indonesia. Instead, the move represents a strategic pivot to deepen investment in the promising Andaman offshore region, where it has agreed to accelerate exploration and development efforts.