This announcement contains inside information for the purposes of Article 7 of the UK version of Regulation (EU) No 596/2014 which is part of UK law by virtue of the European Union (Withdrawal) Act 2018, as amended ("MAR"). Upon the publication of this announcement via a Regulatory Information Service, this inside information is now considered to be in the public domain.

10 September 2026

Sintana Energy, Inc.

("Sintana" or "the Company")

KON-16, Angola: Execution of Definitive Transaction Documentation

Toronto & London, September 10, 2026 - Sintana Energy Inc. (TSX-V: SEI, AIM: SEI, OTCQX: SEUSF) is pleased to announce the entry into definitive agreements for the acquisition of an interest in the Block KON-16 in the onshore Kwanza Basin, Angola, first announced on 14 May 2025.

The agreements comprise a share purchase agreement (the "SPA") and a shareholders' agreement (the "Shareholders Agreement") relating to Corcel KON-16 Limited ("CorKon"), the Corcel Plc group company which will hold an 85% participating interest in Block KON-16. The agreements provide for Sintana's acquisition of an indirect 5% participating interest in Block KON-16, through the purchase of shares in CorKon, and establish the governance, funding and transfer arrangements applicable to CorKon following Completion.

In addition to the 5% indirect participating interest, the agreements also provide for Sintana to receive a net profit interest of 2.5% of Corcel's net proceeds from Block KON-16 after first oil until aggregate payments of US$50 million have been made, reducing to 1.5% thereafter.

Completion of the transaction remains conditional upon governmental, regulatory and third-party approvals, including those required in Angola, as well as applicable AIM and TSX Venture Exchange requirements. These are expected to be finalized prior to year-end 2026. Aggregate consideration for the acquisition is US$2.5 million, comprising a US$500,000 initial payment previously paid to Corcel, and a US$2.0 million cash balance payable at completion.

Corcel has also provided an operational update in relation to Block KON-16, the highlights of which are:

o Final PSTM seismic volumes for recently acquired 2D has been received. This dataset materially enhances imaging and structural definition across the block and is being incorporated into the ongoing prospect maturation, well-location selection and partner technical-review processes;

o A geomechanical program has been completed, providing the technical basis for detailed drilling engineering and well design;

o NRG has been appointed for the next phase of engineering and well design for the Block KON-16 exploration drilling campaign; and

o Corcel has confirmed it is targeting drilling of a pre-salt exploration well on Block KON-16 in 2027, subject to final technical selection, approvals, financing, rig availability and partner alignment.

Robert Bose, Chief Executive Officer of Sintana Energy, said: "We are very pleased to reach this milestone with our partners at Corcel. The continuing progress and emergence of the opportunity on KON-16 positions us to realise on this offshore-scaled resource with an onshore cost. We look forward to providing further updates over the coming quarters."

For further information, please contact:

About Sintana

Sintana, the Canadian parent company of a group of companies, is focused on the acquisition, exploration, potential development, and ultimately the monetisation of a diverse portfolio of interests in high-impact assets with significant hydrocarbon resource potential in emerging "frontier" geographies. Specifically, this includes interests in eight licences in two countries, Namibia and Uruguay, as well as pending indirect interests in additional licences in Namibia and Angola (and legacy assets in Colombia and The Bahamas), providing exposure to a range of geologic plays, basins, operators, regulators, jurisdictions and geopolitical regimes.

https://www.sintanaenergy.com 

Forward-looking statements

Certain statements in this announcement are, or may be deemed to be, forward looking statements, including statements with respect to the anticipated completion of the Acquisition on terms currently proposed or at all, the receipt of all associated regulatory approvals and satisfaction of all closing conditions, and the prospective nature of PEL 37. Forward looking statements are identified by their use of terms and phrases such as ''believe'', ''could'', "should" ''envisage'', ''estimate'', ''intend'', ''may'', ''plan'', ''will'' or the negative of those, variations or comparable expressions, including references to assumptions. These forward-looking statements are not based on historical facts but rather on the Company's current expectations and assumptions regarding the Company's future growth, results of operations, performance, future capital and other expenditures (including the amount, nature and sources of funding thereof), competitive advantages, business prospects and opportunities. Such forward looking statements reflect the Company's current beliefs and assumptions and are based on information currently available to the Company. Several factors could cause actual results to differ materially from the results discussed in the forward-looking statements including risks associated with vulnerability to general economic and business conditions, competition, failure to obtain regulatory approvals or satisfy conditions precedent to the completion of the Acquisition, changes in project parameters as plans continue to be refined, environmental and other regulatory changes, actions by governmental authorities, the availability of capital markets, reliance on key personnel, uninsured and underinsured losses and other factors, many of which are beyond the control of the Company. Although any forward-looking statements contained in this announcement are based upon what the Company believes to be reasonable assumptions, the Company cannot assure investors that actual results will be consistent with such forward looking statements. The Company disclaims any obligation to update forward-looking statements contained herein other than as required by applicable law.

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