Gran Tierra Energy Completes Conditions Precedent for Tisquirama Contract

CALGARY, Alberta, May 27, 2026 (GLOBE NEWSWIRE) -- Gran Tierra Energy Inc . (“Gran Tierra” or the “Company”) (NYSE American:GTE)(TSX:GTE)(LSE:GTE) is pleased to announce today that the Company has satisfied all outstanding conditions precedent to the effectiveness of the contract previously announced on March 17, 2026 with Ecopetrol S.A., by which the Company will earn a 49 percent working interest in the Tisquirama block located in the Middle Magdalena Valley Basin of Colombia (the “ Block ”), which contains the Tisquirama and San Roque fields (the “ Fields ”) (the “ Tisquirama Contract ” ) . Production is expressed in barrels of oil equivalent (“ boe ”) per day (“ boepd ”). All dollar amounts are in United States (“ U.S. ”) dollars unless otherwise indicated.

The Tisquirama Contract provides Gran Tierra with the opportunity to apply its proven waterflood expertise and operational model to assets with significant original oil in place (“ OOIP ”) that have historically seen limited secondary recovery and relatively low recovery factors. The Fields are adjacent to Gran Tierra’s operated Acordionero field and share similar geological characteristics, creating the potential for operational synergies and integrated field development. Under the terms of the Tisquirama Contract, Gran Tierra is expected to focus initial Phase 1 capital activity on waterflood expansion from the Company’s operated Acordionero field into the adjoining Fields before accelerating development through wellbore optimization and low-risk infill drilling.

Completion of Phase 1 is achieved with a minimum of $15 million of gross capital expenditures and implementation of continuous water injection, which is currently anticipated to be achieved in the first quarter of 2027, subject to approval of the corresponding plans by the executive committee. Upon completion of Phase 1, Gran Tierra will receive 49 percent of existing base production in addition to 49 percent of incremental production. The Fields averaged approximately 2,500 boepd on a gross basis during 2025.

Gran Tierra expects the Tisquirama Contract to create meaningful operational synergies with Acordionero, including integrated water management, the potential implementation of gas-to-power projects utilizing natural gas production in the area, and the opportunity to manage the Fields as a single operating hub to improve efficiency and maximize long-term value. Contact Information For investor and media inquiries please contact: Gary Guidry, Chief Executive Officer Ryan Ellson, Executive Vice President & Chief Financial Officer +1(403)265-3221 info@grantierra.com About Gran Tierra Energy Inc. Gran Tierra Energy Inc., together with its subsidiaries, is an independent international energy company currently focused on oil and natural gas exploration and production in Canada, Colombia, Ecuador and Azerbaijan. The Company is currently developing its existing portfolio of assets in Canada, Colombia and Ecuador; however, we have recently entered into an exploration, development and production sharing agreement with the State Oil Company of the Republic of Azerbaijan (“ SOCAR ”) and may eventually expand our operations into Azerbaijan and will continue to pursue additional new growth opportunities that would further strengthen the Company’s portfolio.

The Company’s common stock trades on the NYSE American, the Toronto Stock Exchange and the London Stock Exchange under the ticker symbol GTE. Additional information concerning Gran Tierra is available at www.grantierra.com. Except to the extent expressly stated otherwise, information on the Company’s website or accessible from our website or any other website is not incorporated by reference into and should not be considered part of this press release.

Investor inquiries may be directed to info@grantierra.com or (403) 265-3221. Gran Tierra’s filings with the U.S. Securities and Exchange Commission (the “ SEC ”) are available on the SEC website at http://www.sec.gov. Gran Tierra’s Canadian securities regulatory filings are available on SEDAR+ at http://www.sedarplus.ca and UK regulatory filings are available on the National Storage Mechanism website at https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

Forward Looking Statements and Legal Advisories: This press release contains opinions, forecasts, projections, and other statements about future events or results that constitute forward-looking statements within the meaning of the United States Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and financial outlook and forward looking information within the meaning of applicable Canadian securities laws (collectively, “forward-looking statements”), which can be identified by such terms as “expect,” “plan,” “anticipate,” “target,” “outlook,” “can,” “will,” “should,” “guidance,” “estimate,” “forecast,” “signal,” “measures taken to” and “believes,” derivations thereof and similar terms identify forward-looking statements. Such forward-looking statements include, but are not limited to, statements regarding the satisfaction of the conditions precedent to, and the timing of the effectiveness of, the Contract, including receipt of regulatory approvals from the SIC; Gran Tierra’s ability to earn its working interest in the Block; the expected timing, cost and scope of the committed work program and Phase 1 capital activities, including the capital carry and social investment; the expected timing of obtaining operatorship and entitlement to base production; the expected allocation of capital and operating expenditures following completion of the Phase 1 carry commitment; OOIP relating to the Block and the Acordionero field, planned waterflood expansion, drilling, development and water injection activities; potential production levels, recovery factors and development potential; the potential use of multi-leg horizontal drilling techniques; and anticipated operational synergies, including water management integration and the potential use of natural gas to support gas-to-power infrastructure. The forward-looking statements contained in this press release reflect several material factors and expectations and assumptions of Gran Tierra including, without limitation, that Gran Tierra will obtain the required regulatory approvals and satisfy the conditions precedent for the Contract to become effective, that Gran Tierra will continue to conduct its operations in a manner consistent with its current expectations, the accuracy of testing and production results and seismic data, pricing and cost estimates (including with respect to commodity pricing and exchange rates), rig availability, the effects of drilling down-dip, the effects of waterflood and multi-stage fracture stimulation operations, the extent and effect of delivery disruptions, and the general continuance of current or, where applicable, assumed operational, regulatory and industry conditions in Canada, Colombia, Ecuador and Azerbaijan and areas of potential expansion, and the ability of Gran Tierra to execute its business and operational plans in the manner currently planned.

Gran Tierra believes the material factors, expectations and assumptions reflected in the forward-looking statements are reasonable at this time, but no assurance can be given that these factors, expectations and assumptions will prove to be correct. Among the important factors that could cause actual results to differ materially from those indicated by the forward-looking statements in this press release are: certain of Gran Tierra’s operations are located in South America and the Company is pursuing activities in other international jurisdictions, including Azerbaijan, and unexpected problems can arise due to guerilla activity, strikes, local blockades or protests, civil unrest, sanctions-related restrictions, or other political instability; technical difficulties and operational difficulties may arise which impact the production, transport or sale of Gran Tierra’s products; other disruptions to local operations; global and regional changes in the demand, supply, prices, differentials or other market conditions affecting oil and natural gas, including inflation and changes resulting from a global health crisis, geopolitical events, including the ongoing conflicts in Ukraine, the Middle East and Venezuela, or from the imposition or lifting of crude oil production quotas or other actions that might be imposed by OPEC and other producing countries and resulting company or third-party actions in response to such changes; changes in commodity prices, including volatility or a prolonged decline in these prices relative to historical or future expected levels; the risk that current global economic and credit conditions may impact oil and natural gas prices and oil and natural gas consumption more than Gran Tierra currently predicts, which could cause Gran Tierra to further modify its strategy and capital spending program; prices and markets for oil and natural gas are unpredictable and volatile; the effect of hedges, the accuracy of productive capacity of any particular field; geographic, political and weather conditions can impact the production, transport or sale of Gran Tierra’s products; the ability of Gran Tierra to execute its business plan, which may include acquisitions, and realize expected benefits from current or future initiatives; the risk that unexpected delays and difficulties in developing currently owned properties may occur; the ability to replace reserves and production and develop and manage reserves on an economically viable basis; the accuracy of testing and production results and seismic data, pricing and cost estimates (including with respect to commodity pricing and exchange rates); the risk profile of planned exploration activities; the effects of drilling down-dip; the effects of waterflood and multi-stage fracture stimulation operations; the extent and effect of delivery disruptions, equipment performance and costs; actions by third parties; the timely receipt of regulatory or other required approvals for Gran Tierra’s operating activities; the failure of exploratory drilling to result in commercial wells; unexpected delays due to the limited availability of drilling equipment and personnel; volatility or declines in the trading price of Gran Tierra’s common stock or bonds; the risk that Gran Tierra does not receive the anticipated benefits of government programs, including government tax refunds; Gran Tierra’s ability to comply with financial covenants in its credit agreement and indentures and make borrowings under its credit agreement; and the risk factors detailed from time to time in Gran Tierra’s periodic reports filed with the SEC, including, without limitation, under the caption “Risk Factors” in Gran Tierra’s Annual Report on Form 10-K for the year ended December 31, 2025 filed on March 4, 2026 and its other filings with the SEC. These filings are available on the SEC’s website at http://www.sec.gov and on SEDAR+ at www.sedarplus.ca and UK regulatory filings are available on the National Storage Mechanism website at https://data.fca.org.uk/#/nsm/nationalstoragemechanism .

The forward-looking statements contained in this press release are based on certain assumptions made by Gran Tierra based on management’s experience and other factors believed to be appropriate. Gran Tierra believes these assumptions to be reasonable at this time, but the forward-looking statements are subject to risks and uncertainties, many of which are beyond Gran Tierra’s control, which may cause actual results to differ materially from those implied or expressed by the forward looking statements. The risk that the assumptions on which the 2026 outlook are based prove incorrect may increase the later the period to which the outlook relates.

All forward-looking statements are made as of the date of this press release and the fact that this press release remains available does not constitute a representation by Gran Tierra that Gran Tierra believes these forward-looking statements continue to be true as of any subsequent date. Actual results may vary materially from the expected results expressed in forward-looking statements. Gran Tierra disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as expressly required by applicable law.

In addition, historical, current and forward-looking sustainability-related statements may be based on standards for measuring progress that are still developing, internal controls and processes that continue to evolve, and assumptions that are subject to change in the future. Gran Tierra’s forward-looking statements are expressly qualified in their entirety by this cautionary statement. Presentation of Oil and Gas Information Boes have been converted on the basis of six thousand cubic feet (“Mcf”) natural gas to 1 boe of oil.

Boes may be misleading, particularly if used in isolation. A boe conversion ratio of 6 Mcf: 1 boe is based on an energy equivalency conversion method primarily applicable at the burner tip and does not represent a value equivalency at the wellhead. In addition, given that the value ratio based on the current price of oil as compared with natural gas is significantly different from the energy equivalent of six to one, utilizing a boe conversion ratio of 6 Mcf: 1 boe would be misleading as an indication of value.

References to a formation where evidence of hydrocarbons has been encountered is not necessarily an indicator that hydrocarbons will be recoverable in commercial quantities or in any estimated volume. Gran Tierra’s reported production is a mix of light crude oil and medium heavy crude oil, tight oil, conventional natural gas, shale gas and natural gas liquids for which there is no precise breakdown since the Company’s sales volumes typically represent blends of more than one product type. Well test results should be considered as preliminary and not necessarily indicative of long-term performance or of ultimate recovery.

Well log interpretations indicating oil and gas accumulations are not necessarily indicative of future production or ultimate recovery. If it is indicated that a pressure transient analysis or well-test interpretation has not been carried out, any data disclosed in that respect should be considered preliminary until such analysis has been completed. References to thickness of “oil pay” or of a formation where evidence of hydrocarbons has been encountered is not necessarily an indicator that hydrocarbons will be recoverable in commercial quantities or in any estimated volume.