Harbour Energy Sells Indonesian Assets to Prime Group in $215 Million Transaction

Harbour Energy sells Natuna Sea Block A & Tuna assets to Indonesia's Prime Group for $215m, streamlining its portfolio to focus on core opportunities.

8 December 2025by Joshua Thompson5 min read207 views

This article covers information on Harbour Energy PLC.

LON:HBR

Harbour Energy offloads Natuna Block A and Tuna to Prime Group for $215 million

Harbour Energy has signed a Sale and Purchase Agreement (SPA) to sell its operated interests in two Indonesian assets – the producing Natuna Sea Block A field and the pre-development Tuna project – to Prime Group for a cash consideration of $215 million. Completion is targeted for Q2 2026, subject to customary regulatory approvals and completion adjustments.

The deal marks a meaningful reshaping of Harbour’s Indonesian footprint, while keeping a toehold in the country through its Andaman Sea discoveries.

What’s being sold and to whom

The package includes:

Natuna Sea Block A – a producing asset where Harbour holds a 28.67% operated interest. It produced around 4 kboepd (thousand barrels of oil equivalent per day, net to Harbour) over the nine months to 30 September 2025, with 2P reserves (proved plus probable) of 7.4 mmboe at year end 2024.
Tuna – a development-stage project where Harbour holds a 50% operated interest. It carried 2C resources (best estimate contingent resources) of 54 mmboe at year end 2024.

The buyer, Prime Group, is an Indonesian oil and gas operator with upstream and downstream businesses, including a 25% interest in the producing Natuna Sea Block B field. On paper, Prime looks like a logical local owner for these assets.

Deal terms, timing and effective dates

Cash consideration	$215 million (subject to customary completion adjustments)
Completion target	Q2 2026 (subject to regulatory approvals)
Interests sold	28.67% in Natuna Sea Block A; 50% in Tuna
Production (Natuna A)	c. 4 kboepd (net to Harbour) in 9M to 30 Sep 2025
Reserves/resources	Natuna A: 7.4 mmboe 2P (YE 2024); Tuna: 54 mmboe 2C (YE 2024)
Effective dates	Natuna A: 1 January 2025; Tuna: on completion

The effective date for Natuna A is set at 1 January 2025. In practice, effective dates and completion adjustments typically align value for cash flows between announcement and completion. Tuna’s effective date will be at completion.

Strategy signal: portfolio high-grading and focus

Harbour frames this as a capital discipline move. Steve Cox, Managing Director of Harbour’s Indonesia Business Unit, said the transaction “supports our strategy to focus capital and resources on our most competitive and material opportunities.” That’s corporate-speak for concentrating spend where returns are strongest and scale is meaningful.

Share𝕏 in

Investing
Polar Capital Technology Trust Reports 102% NAV Growth in Stellar Fiscal Year
Polar Capital Technology Trust sees 102% NAV growth in FY2026, beating its benchmark by 47 points thanks to AI and semiconductor exposure.
JoshuaJuly 10, 2026
Investing

Tagged

Last updated

5 July 2026

Star Rating

No ratings yet

By selling a modest net production position at Natuna A and a development project at Tuna, Harbour is streamlining the Indonesian portfolio while keeping exposure through the Andaman Sea discoveries. It’s tidy portfolio high-grading: exit smaller or non-core operated commitments and reduce future capital calls, while maintaining optionality where the upside looks larger.

Why this matters for shareholders

Cash proceeds: The $215 million headline consideration brings in cash. Use of proceeds is not disclosed. Investors will watch whether it offsets capex, bolsters the balance sheet, or supports shareholder returns.
Risk reduction: Exiting an operated development (Tuna) removes execution and funding risk tied to bringing new barrels online. That can lower future capital intensity.
Simplification: Fewer operated assets in Indonesia should streamline the business. Harbour still plans to remain in-country via the Andaman Sea discoveries, so it’s not a full exit.
Local fit: Prime Group already owns 25% of nearby Natuna Sea Block B. Operational synergies and local focus could improve asset stewardship post-transaction, which can smooth handover risk.

The not-disclosed bits investors will want to know

Use of proceeds – not disclosed.
Any contingent payments or earn-outs – not disclosed. The RNS only references “customary completion adjustments.”
Tax and decommissioning implications – not disclosed.
Impact on group production and guidance post-completion – not disclosed.

None of these omissions are unusual at this stage, but they are the key follow-ups for investors seeking to model the financial impact beyond the headline number.

Risks and timing to completion

The deal is subject to customary approvals and is guided to complete in Q2 2026. The gap between announcement and completion is significant, especially with an effective date for Natuna A set at 1 January 2025. That puts more emphasis on completion adjustments when the transaction closes.

Key risks to keep in mind:

Regulatory approvals: Always the gating item. Timelines can move.
Operational change through 2025: Production, costs and prices could shift before completion, feeding into adjustments.
Project status at Tuna: As a development project, any change in plans or schedule before completion could influence value perceptions, though the RNS doesn’t specify any conditions beyond customary approvals.

Management’s tone and what to watch next

The tone is constructive. Harbour is emphasising strategy, competitiveness and a smooth transition of long-tended assets: “a key milestone for Harbour in Indonesia,” as per Steve Cox’s statement. That suggests the company views this as tidying up the portfolio rather than pulling back from Indonesia entirely.

Watch for:

Regulatory milestones and any update to the Q2 2026 completion target.
Further portfolio moves or clarity on capital allocation priorities.
Updates on the Andaman Sea discoveries, given Harbour’s stated plan to maintain a presence in Indonesia there.

Quick jargon buster

SPA (Sale and Purchase Agreement): The binding contract setting the terms of the asset sale.
2P reserves: Proved plus probable reserves – commercially recoverable with at least a 50% chance.
2C resources: Best estimate of contingent resources – discovered but not yet considered commercially ready for development.
kboepd/mmboe: Thousand barrels of oil equivalent per day / million barrels of oil equivalent.
Effective date: The date from which economic benefits and risks are measured for the deal, with cash adjustments made at completion.

Bottom line: a tidy exit from smaller operated roles, cash in the door

On balance, this looks like a sensible, if unsurprising, portfolio move. Harbour swaps a modest net production stream and a development commitment for $215 million in cash, trims operated exposure in Indonesia, and doubles down on where it sees greater competitive advantage.

The market’s verdict will hinge on what Harbour does with the proceeds and how swiftly it closes in Q2 2026. For now, it’s a strategic clean-up that simplifies the story without abandoning Indonesia.