Gran Tierra Energy Inc. Completes a Transformational Year and Announces a 91% Increase in 2P Reserves and a 146% increase in 3P Reserves

CALGARY, ALBERTA--(Marketwired - Jan 23, 2017) - Gran Tierra Energy Inc. ("Gran Tierra" or the "Company") (NYSE MKT:GTE)(TSX:GTE), a company focused on oil exploration and production in Colombia, today announced the Company's 2016 year-end estimated reserves as evaluated by the Company's independent qualified reserve evaluator McDaniel & Associates Consultants Ltd. ("McDaniel") in a report with an effective date of December 31, 2016 (the "GTE McDaniel Reserves Report"). Gran Tierra has also updated its corporate presentation, which is available on the Company's website.

All dollar amounts are in United States ("U.S.") dollars, unless otherwise indicated. Unless otherwise expressly stated, all reserves and resources values contained in this press release have been calculated in compliance with Canadian National Instrument 51-101 - Standards of Disclosure for Oil and Gas Activities ("NI 51-101") and the Canadian Oil and Gas Evaluation Handbook ("COGEH").

Message to Shareholders

Gary Guidry, President and Chief Executive Officer of Gran Tierra, commented, "Gran Tierra had a transformational year during 2016 in which we expanded, upgraded and diversified our portfolio in Colombia through four strategic and accretive acquisitions: Petroamerica, PetroGranada, PetroLatina and the Ecopetrol 2016 Bid Round, which is expected to close in 2017. We are pleased that in 2016 we were able to add approximately 9.2 million barrels of oil equivalent ("MMBOE") of Proved plus Probable ("2P") working interest before royalties ("WI") reserves organically in both our existing assets and our new assets post-acquisition, despite only commencing exploration and appraisal drilling in late September 2016. Our 2016 exploration drilling delivered 2016 2P WI reserve additions of 2.1 MMBOE in our N-sands exploration play in the acquired Putumayo-7 ("PUT-7") Block. Total 2P WI reserves booked on PUT-7 are now 5.4 MMBOE. Development activities delivered 2P WI reserves additions of 2.6 MMBOE in our newly acquired asset at Acordionero in the Middle Magdalena Basin and 2.0 MMBOE of 2P WI reserves in our legacy asset at Costayaco in the Putumayo Basin from the "A" Limestone. We look forward in 2017 to further proving up Acordionero through ongoing development drilling which targets 48 MMBOE of Possible reserves (out of Acordionero's total Proved plus Probable plus Possible ("3P") WI reserves of 96 MMBOE), and developing the "A" Limestone in Costayaco through horizontal drilling, which commenced at the end of 2016.

During 2016, Gran Tierra's total 2P WI reserves increased by 91% compared with year-end 2015, while the Company's 3P WI reserves increased by 146% over the same time period. In addition, the Company's exploration portfolio has been substantially enhanced and expanded. Our 2P reserves replacement ratio in 2016 was 708%1 including acquisitions. We are also pleased that we were able to increase our 2P reserve life index from 7.8 years to 11.1 years.