SecProbe.io

July 30, 2019
Gary S. Guidry
President and Chief Executive Officer
Gran Tierra Energy Inc.
900, 520-3 Avenue SW
Calgary, Alberta Canada T2P 0R3
Re:Gran Tierra Energy Inc.
Form 10-K for the Fiscal Year ended December 31, 2018
Filed February 27, 2019
File No.: 001-34018
Dear Mr. Guidry:
            We have reviewed your filing and have the following comments.  In some of our
comments, we may ask you to provide us with information so we may better understand your
disclosure.
            Please respond to these comments within ten business days by providing the requested
information or advise us as soon as possible when you will respond.  If you do not believe our
comments apply to your facts and circumstances, please tell us why in your response.
            After reviewing your response to these comments, we may have additional comments.
Form 10-K for the Fiscal Year ended December 31, 2018
Business and Properties
Estimated Reserves, page 10
1.The discussion of probable and possible reserves refers to various circumstances identified
in the definitions under Rule 4-10(a)(18) and (a)(17) of Regulation S-X, respectively,
under which such reserves may be assigned.  Expand your disclosure to further explain the
extent to which one or more of the factors you have identified apply to the probable and
possible reserves disclosed as of December 31, 2018.  Refer to the disclosure requirements
in Item 1202(a)(5) of Regulation S-K.
2.Expand your discussion of the uncertainty relating to probable and possible reserves to
incorporate appropriate cautionary language indicating estimates of probable and possible
reserves (i) are more uncertain than proved reserves, (ii) have not been adjusted for risk
attributable to that uncertainty, and (iii) may not be comparable with each other and
should not be summed arithmetically with each other or with estimates for proved

 FirstName LastNameGary S. Guidry
 Comapany NameGran Tierra Energy Inc.
 July 30, 2019 Page 2
 FirstName LastNameGary S. Guidry
Gran Tierra Energy Inc.
July 30, 2019
Page 2
reserves.  Refer to Item 1202(a)(5) of Regulation S-K and the Compliance and Disclosure
Interpretation Question 105.01.
Proved Undeveloped Reserves, page 11
3.Expand your disclosure of the changes in the net quantities of proved undeveloped
reserves to include an explanation of the material changes related to each line item shown
in your reconciliation.  To the extent that two or more unrelated factors are combined to
arrive at the line item figure, your disclosure should separately identify and quantify each
individual factor that contributed to a material change so that the change in net reserves
between periods is fully explained.

The disclosure of revisions in the previous estimates of reserves in particular should
identify such factors as changes caused by commodity prices, well performance,
unsuccessful and/or uneconomic proved undeveloped locations or the removal of proved
undeveloped locations due to changes in a previously adopted development plan.  Refer to
Item 1203(b) of Regulation S-K.

This comment also applies to the disclosure provided as part of the Supplementary Data
(Unaudited) on page 78 relating to the significant changes in the net quantities of total
proved reserves for each line item shown in the reconciliation, other than production, and
for each of the periods presented.  Refer to FASB ASC 932-235-50-5.
Developed and Undeveloped Acreage, page 12
4.Expand the disclosure of your acreage to discuss the expiration dates of material amounts
of your undeveloped acreage.  Refer to the disclosure requirements under Item 1208(b) of
Regulation S-K.
5.Expand your disclosure to indicate the extent to which you have assigned any proved
undeveloped reserves to locations which are currently scheduled to be drilled after
expiration of the related acreage.  If there are material quantities of net proved
undeveloped reserves relating to such locations, also describe the steps that will be
necessary to extend the time to the expiration of such acreage.
Production, Revenue and Price History, page 12
6.Expand your disclosure of production and average sales prices, to include for the
Costayaco, Moqueta and Acordionero fields, and any other fields that contain 15% or
more of your total proved reserves, the net quantities of natural gas production and the
related gas sales prices for each of the last three fiscal years.  Refer to the disclosure
requirements under Item 1204(a) of Regulation S-K.
7.Your tabular disclosure of production and price history appears to be limited to
information relating specifically to the Costayaco, Moqueta and Acordionero fields.

 FirstName LastNameGary S. Guidry
 Comapany NameGran Tierra Energy Inc.
 July 30, 2019 Page 3
 FirstName LastName
Gary S. Guidry
Gran Tierra Energy Inc.
July 30, 2019
Page 3
Expand your tabulation to present comparable figures for the total aggregate amounts of
production, by final product sold of oil and natural gas, relating to all of your producing
assets, for each of the last three fiscal years.  Refer to the disclosure requirements under
Item 1204(a) of Regulation S-K.
8.The tabular presentation of production for the Costayaco, Moqueta and Acordionero fields
and the preceding discussion indicates the figures shown in the table include both oil and
NGL production.  However, footnote 1 to your reconciliation of the changes in total
proved reserves on page 34 indicates liquids reserves, and by extension the production
figures, for all periods are 100% oil.  Revise your disclosure of production on page 12 to
reconcile the apparent inconsistency in the description of your liquids production, or tell
us why a revision is not necessary.
Financial Statements
Supplementary Data (Unaudited), page 77
9.We note that you have provided a roll-forward of acquisition, exploration and
development costs in your tabulation on page 79, including balances reflecting the
summation of such costs as of December 31, 2015, 2016, 2017 and 2018.  However, the
balances that you report do not coincide with the amounts that you report in Note 5 on
page 63, which appear to be those you present in conformity with U.S. GAAP.

As the disclosure requirements outlined in FASB ASC 932-235-50-17 through 20 include
amounts that may or may not be capitalized, and do not encompass DD&A, ceiling-test
write-downs, impairments, or other adjustments to capitalized costs, please clarify the
nature of the balances that you report.

Please observe the summary nature of this disclosure requirement, without vertical
summations or balances in the illustration at FASB ASC 932-235-55-4.
            We remind you that the company and its management are responsible for the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.
            You may contact John Hodgin, Petroleum Engineer, at (202) 551-3699 with questions
regarding engineering comments.  Please contact Joseph Klinko at (202) 551-3824 or Karl
Hiller, Accounting Branch Chief at (202) 551-3686 with any other questions.
Sincerely,
Division of Corporation Finance
Office of Natural Resources