• Total Current Average Production⁽¹⁾ of Approximately 36,800 BOPD

• Second Quarter-to-Date 2023 Average Production⁽²⁾ of Approximately 33,600 BOPD, Up 6% from First Quarter 2023

• Achieved Acordionero Field Average Production⁽²⁾ of Approximately 18,600 BOPD

• Acordionero, Costayaco and Moqueta Infill Development Well Drilling Programs Yielding Exciting Results

• During 2023 Year-to-Date, 19 Development Wells Drilled, Consisting of 12 New Producers and 7 New Injectors

CALGARY, Alberta, May 30, 2023 (GLOBE NEWSWIRE) -- Gran Tierra Energy Inc. ("Gran Tierra" or the "Company") (NYSE American:GTE)(TSX:GTE)(LSE:GTE) today announced an operational update. All dollar amounts are in United States dollars, and production amounts are on an average working interest before royalties ("WI") basis unless otherwise indicated. Per barrel ("bbl") and bbl of oil per day ("BOPD") amounts are based on WI sales before royalties.

Message to Shareholders

Gary Guidry, President and Chief Executive Officer of Gran Tierra, commented: "During 2023 year-to-date, Gran Tierra has completed most of its development program for 2023 with the drilling of 19 development wells, consisting of 12 new production wells and 7 new water injection wells. We remain on track and on budget with our development and exploration drilling programs for 2023. We are also very pleased with the exciting oil production results that we are seeing from our Acordionero, Costayaco and Moqueta infill development well drilling programs.

The success of our 2023 development program has been an important factor in our ongoing ramp up in oil production during 2023 and continues to demonstrate the excellent production capabilities of our major assets. We expect the ongoing positive results from our waterflood projects in the Acordionero, Costayaco, Moqueta and Suroriente fields to continue adding oil production from existing and new wells for the remainder of 2023. We are also beginning to see positive results in our polymer flood project in Acordionero.

By completing the majority of our development program in the first 5 months of 2023, we expect to realize higher oil production for the rest of 2023. With most of our development capital behind us, this should allow us to maximize cash flow. We believe the Company is well positioned to optimize value and grow production from our assets through continued enhanced oil recovery activities as demonstrated by our total current average production⁽¹⁾ of approximately 36,800 BOPD."

Operations Update:

Production

• Gran Tierra has begun to ramp up production in the latter half of second quarter 2023, as newly drilled Acordionero, Costayaco and Moqueta oil wells have been steadily brought online. Gran Tierra's total current average production⁽¹⁾ is approximately 36,800 BOPD.
• During second quarter-to-date 2023, The Company has achieved total average production⁽²⁾ of approximately 33,600 BOPD.
• During 2023 year-to-date, Gran Tierra has achieved total average production⁽³⁾ of approximately 32,400 BOPD, which is within the Company's previous forecast range for 2023 of 32,000-34,000 BOPD.

Development

• During 2023 year-to-date, Gran Tierra has drilled a total 19 development wells in Colombia, consisting of 12 new production wells and 7 new water injection wells:
  • Acordionero:
    • Development drilling resumed in January 2023 with a 10-well program that was completed in April 2023.
    • 6 wells are on production and 4 wells are on water injection.
    • As a result of the development program and continued good performance of the field's enhanced oil recovery via waterflood, Acordionero has achieved average production⁽²⁾ of approximately 18,600 BOPD during second quarter-to-date 2023, which is the highest level since May 2019.
    • During second quarter 2023, Gran Tierra achieved a new water injection record of approximately 72,000 bbl of water injected per day.
    • The polymer flood pilot was expanded with the start up of a third polymer injection well during second quarter 2023. Acordionero's polymer flood pilot is expected to increase the field's ultimate oil recovery.
  • Costayaco:
    • Gran Tierra has finished drilling all 7 wells in the Company's 2023 Costayaco development campaign. The program consisted of 4 production wells and 3 water injection wells.
    • 2 production wells are currently on long-term production test and 2 water injection wells started up during second quarter 2023.
    • A summary of the recent production tests for the 2 new Costayaco production wells is provided below:

*scf = standard cubic feet

• The remaining 2 new production wells and 1 new water injection well are expected to be completed and tied-in during June 2023.
• The completion and stimulation of the remaining production wells and waterflood optimization through additional water injection are expected to continue to grow Costayaco's oil production throughout the year.
• Moqueta:
  • 2 production wells that were drilled during first quarter 2023 have both been stimulated and placed on production.
  • A summary of the recent production tests for the 3 newest Moqueta production wells is provided below:

*scf = standard cubic feet

• 1 production well is currently being drilled, with one additional production well expected to be drilled during late June - early July 2023.
• The 2 additional production wells, along with 2 planned conversions of existing wells into water injection wells, are expected to grow Moqueta's oil production and optimize its waterflood.

¹ Total current average production is for the 15-day period of May 14, 2023 to May 28, 2023.
² Total average production during second quarter-to-date 2023 is for the period of April 1, 2023 to May 28, 2023.
³ Total average production during 2023 year-to-date is for the period of January 1, 2023 to May 28, 2023.

Corporate Presentation:

Gran Tierra's Corporate Presentation is available on the Company website at www.grantierra.com.

Contact Information:

For investor and media inquiries please contact:
Gary Guidry
President & Chief Executive Officer

Ryan Ellson
Executive Vice President & Chief Financial Officer

Rodger Trimble
Vice President, Investor Relations

+1-403-265-3221
[email protected]

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 Colombia and Ecuador. The Company is currently developing its existing portfolio of assets in Colombia and Ecuador and will continue to pursue additional 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. Information on the Company's website (including the Corporate Presentation referenced above) does not constitute a part of this press release. Investor inquiries may be directed to [email protected] or (403) 265-3221.

Gran Tierra's U.S. Securities and Exchange Commission ("SEC") filings are available on the SEC website at www.sec.gov. The Company's Canadian securities regulatory filings are available on SEDAR at www.sedar.com and UK regulatory filings are available on the National Storage Mechanism ("the NSM") website at https://data.fca.org.uk/#/nsm/nationalstoragemechanism. Gran Tierra's filings on the SEC, SEDAR and the NSM websites are not incorporated by reference into this press release.

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"). The use of the words "expect," "plan," "can," "will," "should," "guidance," "forecast," "signal," "progress," and "believes," derivations thereof and similar terms identify forward-looking statements. In particular, but without limiting the foregoing, this press release contains forward-looking statements regarding: the Company's expected future production (including as a result of our testing results), the Company's drilling program, and future free cash flow. 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 continue to conduct its operations in a manner consistent with its current expectations, pricing and cost estimates (including with respect to commodity pricing and exchange rates), and the general continuance of assumed operational, regulatory and industry conditions in Colombia and Ecuador, and the ability of Gran Tierra to execute its business and operational plans in the manner currently planned.

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: Gran Tierra's operations are located in South America and unexpected problems can arise due to guerilla activity, strikes, local blockades or protests; technical difficulties and operational difficulties may arise which impact the production, transport or sale of our products; other disruptions to local operations; global health events; global and regional changes in the demand, supply, prices, differentials or other market conditions affecting oil and gas, including inflation and changes resulting from a global health crisis, the Russian invasion of Ukraine, 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 the resulting company or third-party actions in response to such changes; changes in commodity prices, including volatility or a decline in these prices relative to historical or future expected levels; the risk that current global economic and credit conditions may impact oil prices and oil 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 accuracy of testing and production results and seismic data, pricing and cost estimates (including with respect to commodity pricing and exchange rates); 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 our products; the ability of Gran Tierra to execute its business plan and realize expected benefits from current 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 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 our 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 our 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 any credit agreement; capital market disruptions; and the risk factors detailed from time to time in Gran Tierra's periodic reports filed with the Securities and Exchange Commission, including, without limitation, under the caption "Risk Factors" in Gran Tierra's Annual Report on Form 10-K for the year ended December 31, 2022 and its other filings with the Securities and Exchange Commission. These filings are available on the Securities and Exchange Commission website at http://www.sec.gov and SEDAR at www.sedar.com.

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 risk 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. In particular, the unprecedented nature of the current economic downturn, pandemic and industry decline may make it particularly difficult to identify risks or predict the degree to which identified risks will impact Gran Tierra's business and financial condition. 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.

Presentation of Oil and Gas Information:

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 and heavy crude oil for which there is not a precise breakdown since the Company's oil sales volumes typically represent blends of more than one type of crude oil. 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.