PRESS RELEASE

5 December 2022

Gran Tierra Energy Inc. Provides Operational and Financial Update

• Ecuador Exploration: Charapa Norte-1 Well Producing at Average Rate of 1,188 BOPD
• Colombia Exploration: Rose-1 Well Producing at Average Rate of 305 BOPD
• Bought Back 15 Million Gran Tierra Shares of Common Stock for $20 Million Since September 1, 2022

CALGARY, Alberta, Dec. 05, 2022 (GLOBE NEWSWIRE) — Gran Tierra Energy Inc. (“Gran Tierra“ or the “Company“) (NYSE American:GTE) (TSX:GTE) (LSE:GTE) today announced an operational and financial 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 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: “We are excited to share further updates on our exploration program. The Company has recently drilled four independent prospects, two in Ecuador and two in Colombia. All four have produced oil from different reservoir zones. We believe these prospects may offer future development opportunities in 2023 and beyond.

In the Oriente Basin of Ecuador, we are particularly pleased with the results of the Charapa Norte-1 well, which is producing over 1,100 BOPD with virtually no water. We believe the Charapa Norte prospect offers future well locations that Gran Tierra could potentially drill in 2023, which would further delineate the Hollin Sand in the Charapa Block.

In the Putumayo Basin of Colombia, ongoing positive results from the Rose-1 well, which is producing about 300 BOPD and virtually no water, may indicate that there are potential future well locations in the ALEA-1848 Block that could also be drilled.

With fourth quarter-to-date 2022 total Company average production⁽¹⁾ of approximately 32,000 BOPD, and current total average production of about 33,000 BOPD, we look forward to finishing 2022 on a strong note. We are also excited about our 2023 development and exploration capital programs and potential future share and bond buybacks. We plan to issue a press release outlining our 2023 production and financial guidance on or around December 8, 2022.”

Operations Update:

• Production
  • During fourth quarter-to-date 2022, Gran Tierra’s total average production⁽¹⁾ has been approximately 32,000 BOPD.
  • The Company’s current total average production is approximately 33,000 BOPD.
• Ecuador Exploration:
  • Charapa Block (Gran Tierra 100% WI) – Charapa Norte-1 Well:
    • Gran Tierra’s second Ecuador well has been successfully completed in the Hollin Sand and is now being production tested.
    • During a 4-day period (December 1 to December 4, 2022), the Charapa Norte-1 well produced on a jet pump with minimal draw down at a stable average rate of 1,188 BOPD (29-degree API gravity oil) and 1 bbl of water (“BWPD”), with a gas-oil ratio (“GOR”) of 120 standard cubic feet per stock tank bbl (“scf/bbl”).
    • Gran Tierra plans to continue to monitor and adjust the injection pressure of this well’s jet pump for optimal production performance.
    • The Company is also currently planning to drill two follow-up exploration wells on the Charapa Block during 2023.
  • Chanangue Block (Gran Tierra 100% WI) – Bocachico-1 Well:
    • Gran Tierra’s first Ecuador well has been producing from the T Sand.
    • The Bocachico-1 is producing at a stable average rate of 227 BOPD (36-degree API gravity oil) and 264 BWPD, with a GOR of 487 scf/bbl. The Company continues to evaluate potential to isolate the source of water production in this well.
    • Using 3D seismic data, the Company plans to drill two follow-up exploration wells on the Chanangue Block during 2023.
• Colombia Exploration:
  • ALEA-1848 Block (Gran Tierra 100% WI) – Rose-1 Well:
    • The Rose-1 well has been producing from the N Sand on a jet pump and is producing at a stable average rate of 305 BOPD (15.5-degree API gravity oil) and 2 BWPD, with a GOR of 13 scf/bbl.
    • Gran Tierra has provided a notice of discovery for the Rose-1 well to Colombia’s Agencia Nacional de Hidrocarburos (“ANH”) and, while continuing to produce the Rose-1 well, plans to prepare an evaluation area proposal for submission to the ANH prior to the end of 2022.
  • Midas Block (Gran Tierra 100% WI) – Gaitas-1 and -2 Wells:
    • Based on the encouraging results of the Gaitas-1 exploration well, the Company has submitted a notice of discovery to the ANH.
    • Gran Tierra has also drilled and completed the Gaitas-2 exploration well, which penetrated the Umir Formation.
    • Gaitas-2 has found potential oil reservoir in the Lisama A and C Sands. The Lisama Sands are the reservoir zones which produce oil at Gran Tierra’s Acordionero oil field, which is located approximately 7 kilometers to the north of the Gaitas wells. Production testing of the Lisama A Sand is currently underway at Gaitas-2.
• Colombia Development:
  • Moqueta Development Campaign:
    • On November 28, 2022, the Company spud the first development well in the Moqueta field since 2016. This well is expected to reach its planned total depth by mid-December 2022.
  • Drilling Rigs Secured for 2023:
    • The Company has executed all required service contracts for planned 2023 development drilling in Colombia.

Financial Update:

• Share Buybacks: Pursuant to Gran Tierra’s current normal course issuer bid, Gran Tierra has purchased approximately 15 million shares since September 1, 2022, representing about 4.1% of shares outstanding, for a total purchase price of $20 million, at an average price of approximately $1.33 per share.

_{⁽¹⁾ Gran Tierra’s fourth quarter-to-date 2022 total Company average production is for the period of October 1 – December 4, 2022.}

Corporate Presentation:

Gran Tierra’s Corporate Presentation has been updated and 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

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 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 info@grantierra.com 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, the Company’s potential debt repayments and share repurchases, and its positioning for the remainder 2022. 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 (including the ongoing COVID-19 pandemic); 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 obtain a new credit agreement and to comply with financial covenants in its credit agreement and indentures and make borrowings under any credit agreement; 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, 2021 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.