Exhibit 99.1



DeGolyer
and MacNaughton

5001
Spring Valley Road

Suite
800 East

Dallas,
Texas 75244





April 11,
2017



GeoPark Limited

Florida 851, Piso 1

Buenos Aires, Argentina



Ladies and Gentlemen:



Pursuant
to your request, we have conducted a reserves evaluation of the net proved oil, condensate, and gas reserves, as of December 31,
2016, of certain selected properties that GeoPark Limited (GeoPark) has represented that it owns. This evaluation was completed
on April 11, 2017. The properties evaluated consist of working interests located in Chile, Colombia, Brazil, and Peru. GeoPark
has represented that these properties account for 100 percent on a net equivalent barrel basis of GeoPark’s net proved reserves
as of December 31, 2016. The net proved reserves estimates have been prepared in accordance with the reserves definitions of Rules
4–10(a) (1)–(32) of Regulation S–X of the Securities and Exchange Commission (SEC) of the United States. This
report was prepared in accordance with guidelines specified in Item 1202 (a)(8) of Regulation S-K and is to be used for inclusion
in certain SEC filings by GeoPark.



Reserves
estimates included herein are expressed as net reserves. Gross reserves are defined as the total estimated petroleum to be produced
from these properties after December 31, 2016. Net reserves are defined as that portion of the gross reserves attributable to
the interests owned by GeoPark after deducting all interests owned by others and royalties paid in kind. GeoPark has advised that
its interests include interests of minority shareholders not owned by GeoPark.



Estimates
of oil, condensate, and gas reserves should be regarded only as estimates that may change as further production history and additional
information become available. Not only are such reserves estimates based on that information which is currently available, but
such estimates are also subject to the uncertainties inherent in the application of judgmental factors in interpreting such information.






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Data
used in this evaluation were obtained from reviews with GeoPark personnel, from GeoPark files, from records on file with the appropriate
regulatory agencies, and from public sources. In the preparation of this report we have relied, without independent verification,
upon such information furnished by GeoPark with respect to property interests, production from such properties, current costs
of operation and development, current prices for production, agreements relating to current and future operations and sale of
production, and various other information and data that were accepted as represented. A field examination of the properties was
not considered necessary for the purposes of this report.



Methodology and Procedures



Estimates
of reserves were prepared by the use of appropriate geologic, petroleum engineering, and evaluation principles and techniques
that are in accordance with practices generally recognized by the petroleum industry as presented in the publication of the Society
of Petroleum Engineers entitled “Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserves Information
(Revision as of February 19, 2007).” The method or combination of methods used in the analysis of each reservoir was tempered
by experience with similar reservoirs, stage of development, quality and completeness of basic data, and production history.



Based
on the current stage of field development, production performance, the development plans provided by GeoPark, and the analyses
of areas offsetting existing wells with test or production data, reserves were classified as proved.



When
applicable, the volumetric method was used to estimate the original oil in place (OOIP) and the original gas in place (OGIP).
Structure and isopach maps were constructed to estimate reservoir volume. Electrical logs, radioactivity logs, core analyses,
and other available data were used to prepare these maps as well as to estimate representative values for porosity and water saturation.
When adequate data were available and when circumstances justified, material balance and other engineering methods were used to
estimate OOIP or OGIP.



Estimates
of ultimate recovery were obtained after applying recovery factors to OOIP or OGIP. These recovery factors were based on consideration
of the type of energy inherent in the reservoirs, analyses of the petroleum, the structural positions of the properties, and the
production histories. When applicable, material balance and other engineering methods were used to estimate recovery factors.
In such cases, an analysis of reservoir performance, including production rate, reservoir pressure, and gas-oil ratio behavior,
was used in the estimation of reserves.








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For
depletion-type reservoirs or those whose performance disclosed a reliable decline in producing-rate trends or other diagnostic
characteristics, reserves were estimated by the application of appropriate decline curves or other performance relationships.
In the analyses of production-decline curves, reserves were estimated only to the limits of economic production or to the limit
of the production licenses as appropriate.



Gas
quantities estimated herein are expressed as sales gas. Sales gas is defined as the total gas to be produced from the reservoirs,
measured at the point of delivery, after reduction for fuel usage, flare, and shrinkage resulting from field separation and processing.
Gas quantities estimated herein are sales gas volumes expressed at a temperature base of zero degrees Celsius (°C) and a pressure
base of 1 kilogram per square centimeter for the fields in Chile and a temperature base of 20 °C and a pressure base of 1
atmosphere for the field in Brazil.



The
oil and condensate reserves estimated in this report are expressed in terms of 42 United States gallons per barrel. Oil and condensate
reserves estimated herein are those to be recovered by conventional field operations. For reporting purposes, oil and condensate
reserves have been estimated separately and are presented herein as a summed quantity.



Definition of Reserves



Petroleum
reserves included in this report are classified as proved. Only proved reserves have been evaluated for this report. Reserves
classifications used in this report are in accordance with the reserves definitions of Rules 4–10(a) (1)–(32) of Regulation
S–X of the SEC. Reserves are judged to be economically produciblein future
years from known reservoirs under existing economic and operating conditions and assuming continuation of current regulatory practices
using conventional production methods and equipment. In the analyses of production-decline curves, reserves were estimated only
to the limit of economic rates of production under existing economic and operating conditions using prices and costs consistent
with the effective date of this report, including consideration of changes in existing prices provided only by contractual arrangements
but not including escalations based upon future conditions. The petroleum reserves are classified as follows:








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Proved
oil and gas reserves – Proved oil and gas reserves are those quantities of oil and gas, which, by analysis of geoscience
and engineering data, can be estimated with reasonable certainty to be economically producible—from a given date forward,
from known reservoirs, and under existing economic conditions, operating methods, and government regulations—prior to the
time at which contracts providing the right to operate expire, unless evidence indicates that renewal is reasonably certain, regardless
of whether deterministic or probabilistic methods are used for the estimation. The project to extract the hydrocarbons must have
commenced or the operator must be reasonably certain that it will commence the project within a reasonable time.



(i)
The area of the reservoir considered as proved includes:



(A)
The area identified by drilling and limited by fluid contacts, if any, and (B) Adjacent undrilled portions of the reservoir that
can, with reasonable certainty, be judged to be continuous with it and to contain economically producible oil or gas on the basis
of available geoscience and engineering data.



(ii)
In the absence of data on fluid contacts, proved quantities in a reservoir are limited by the lowest known hydrocarbons (LKH)
as seen in a well penetration unless geoscience, engineering, or performance data and reliable technology establishes a lower
contact with reasonable certainty.



(iii)
Where direct observation from well penetrations has defined a highest known oil (HKO) elevation and the potential exists for an
associated gas cap, proved oil reserves may be assigned in the structurally higher portions of the reservoir only if geoscience,
engineering, or performance data and reliable technology establish the higher contact with reasonable certainty.



(iv)
Reserves which can be produced economically through application of improved recovery techniques (including, but not limited to,
fluid injection) are included in the proved classification when:








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(A)
Successful testing by a pilot project in an area of the reservoir with properties no more favorable than in the reservoir as a
whole, the operation of an installed program in the reservoir or an analogous reservoir, or other evidence using reliable technology
establishes the reasonable certainty of the engineering analysis on which the project or program was based; and (B) The project
has been approved for development by all necessary parties and entities, including governmental entities.



(v)
Existing economic conditions include prices and costs at which economic producibility from a reservoir is to be determined. The
price shall be the average price during the 12-month period prior to the ending date of the period covered by the report, determined
as an unweighted arithmetic average of the first-day-of-the-month price for each month within such period, unless prices are defined
by contractual arrangements, excluding escalations based upon future conditions.



Developed
oil and gas reserves – Developed oil and gas reserves are reserves of any category that can be expected to be recovered:



(i)
Through existing wells with existing equipment and operating methods or in which the cost of the required equipment is relatively
minor compared to the cost of a new well; and



(ii)
Through installed extraction equipment and infrastructure operational at the time of the reserves estimate if the extraction is
by means not involving a well.



Undeveloped
oil and gas reserves –Undeveloped oil and gas reserves are reserves of any category that are expected to be recovered
from new wells on undrilled acreage, or from existing wells where a relatively major expenditure is required for recompletion.



(i)
Reserves on undrilled acreage shall be limited to those directly offsetting development spacing areas that are reasonably certain
of production when drilled, unless evidence using reliable technology exists that establishes reasonable certainty of economic
producibility at greater distances.








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(ii)
Undrilled locations can be classified as having undeveloped reserves only if a development plan has been adopted indicating that
they are scheduled to be drilled within five years, unless the specific circumstances justify a longer time.



(iii)
Under no circumstances shall estimates for undeveloped reserves be attributable to any acreage for which an application of fluid
injection or other improved recovery technique is contemplated, unless such techniques have been proved effective by actual projects
in the same reservoir or an analogous reservoir, as defined in [section 210.4–10 (a) Definitions], or by other evidence
using reliable technology establishing reasonable certainty.



Primary Economic Assumptions



The
following economic assumptions were used for estimating existing and future prices and costs, expressed in United States dollars
(U.S.$):



Oil
and Condensate Prices



GeoPark
has represented that the oil and condensate prices for the properties in Brazil and Peru were based on a 12-month average price
for West Texas Intermediate (WTI), calculated as the unweighted average of the first-day-of-the-month price for each month within
the 12-month period prior to the end of the reporting period. GeoPark represented that the 12-month average WTI reference price
was $42.56 per barrel. GeoPark has also represented that the oil and condensate prices for the properties in Chile and Colombia
were based on a 12-month average price for Brent, calculated as the unweighted average of the first-day-of-the-month price for
each month within the 12-month period prior to the end of the reporting period. Geopark represented that the 12-month average
Brent reference price was $43.06 per barrel.








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For
the fields located in Chile, the volume-weighted average adjusted product price attributable to estimated proved reserves was
U.S.$35.80 per barrel for oil and condensate. For the fields located in Colombia, the volume-weighted average adjusted product
price attributable to estimated proved reserves was U.S.$23.40 per barrel for oil. For the Manati field in Brazil, the average
adjusted product price attributable to estimated proved reserves was U.S.$40.20 per barrel for condensate. For the Situche field
in Peru, the average adjusted product price attributable to estimated proved reserves was U.S.$50.56 per barrel for oil. GeoPark
supplied differentials by field to the reference prices, and these prices were held constant for the lives of the properties.



Gas
Prices



GeoPark
has represented that the gas prices are defined by contractual agreements and their expected extensions, which are based on specific
market conditions. The volume-weighted average adjusted product price attributable to estimated proved reserves for the fields
located in Chile was U.S.$4.23 per thousand cubic feet (Mcf). The average adjusted product price attributable to estimated proved
reserves for the Manati field in Brazil was U.S.$6.70 per Mcf. These prices were held constant for the lives of the properties.
There are no gas sales for the fields in Colombia or Peru.



Operating
Expenses, Capital Costs, and Abandonment Costs



Operating
expenses and capital costs, based on information provided by GeoPark, were used in estimating future costs required to operate
the properties. In certain cases, future costs, either higher or lower than existing costs, may have been used because of anticipated
changes in operating conditions. These costs were not escalated for inflation. Abandonment costs were provided by GeoPark.



While
the oil and gas industry may be subject to regulatory changes from time to time that could affect an industry participant’s
ability to recover its oil and gas reserves, we are not aware of any such governmental actions which would restrict the recovery
of the December 31, 2016, estimated proved oil and gas reserves.








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Our
estimates of GeoPark’s net proved reserves attributable to the reviewed properties were based on the definition of proved
reserves of the SEC and are summarized as follows, expressed in thousands of barrels (Mbbl), millions of cubic feet (MMcf), and
millions of barrels of oil equivalent (MMboe):



|                         |  | Estimated by DeGolyer and MacNaughton Net Proved Reserves as of December 31, 2016
|------------------------ |  | ---------------------------------------------------------------------------------
|                         |  |                                                                                  
|                         |  |                                                                                  
|Chile                    |  |                                                                                  
|Proved Developed         |  |                                                                                  
|Proved Undeveloped       |  |                                                                                  
|                         |  |                                                                                  
|Total Chile              |  |                                                                                  
|                         |  |                                                                                  
|Colombia                 |  |                                                                                  
|Proved Developed         |  |                                                                                  
|Proved Undeveloped       |  |                                                                                  
|                         |  |                                                                                  
|Total Colombia           |  |                                                                                  
|                         |  |                                                                                  
|Brazil                   |  |                                                                                  
|Proved Developed         |  |                                                                                  
|Proved Undeveloped       |  |                                                                                  
|                         |  |                                                                                  
|Total Brazil             |  |                                                                                  
|                         |  |                                                                                  
|Peru                     |  |                                                                                  
|Proved Developed         |  |                                                                                  
|Proved Undeveloped       |  |                                                                                  
|                         |  |                                                                                  
|Total Peru               |  |                                                                                  
|                         |  |                                                                                  
|Total Proved Developed   |  |                                                                                  
|Total Proved Undeveloped |  |                                                                                  
|                         |  |                                                                                  
|Total Proved             |  |                                                                                  
|                         |  |                                                                                  





Notes:



| | 1. | Gas is converted to oil equivalent using an energy equivalent
factor of 6,000 cubic feet of gas per 1 barrel of oil equivalent.
| | -- | -------------------------------------------------------------------------------------------------------------------------------



| | 2. | Net reserves include the interests of minority shareholders
not owned by GeoPark.
| | -- | ---------------------------------------------------------------------------------



| | 3. | For Chile, the net proved reserves attributable to minority
interests owned by others include 1,328 Mbbl of oil and condensate and 7,356 MMcf of sales gas.
| | -- | -----------------------------------------------------------------------------------------------------------------------------------------------------------



| | 4. | For Colombia, the net proved reserves attributable to
minority interests owned by others include 7,468 Mbbl of oil.
| | -- | -------------------------------------------------------------------------------------------------------------------






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In
our opinion, the information relating to estimated proved reserves of oil, condensate, and gas contained in this report has been
prepared in accordance with Paragraphs 932-235-50-4 and 932-235-50-6 through 932-235-50-9 of the Accounting Standards Update 932-235-50,
Extractive Industries – Oil and Gas (Topic 932): Oil and Gas Reserve Estimation and Disclosures (January 2010) of
the Financial Accounting Standards Board and Rules 4–10(a) (1)–(32) of Regulation
S–X and Rules 302(b), 1201, 1202(a) (1), (2), (3), (4), (8), and 1203(a) of Regulation S–K of the Securities and Exchange
Commission; provided, however, that estimates of proved developed and proved undeveloped reserves are not presented at the beginning
of the year.



To
the extent the above-enumerated rules, regulations, and statements require determinations of an accounting or legal nature, we,
as engineers, are necessarily unable to express an opinion as to whether the above-described information is in accordance therewith
or sufficient therefor.



DeGolyer
and MacNaughton is an independent petroleum engineering consulting firm that has been providing petroleum consulting services
throughout the world since 1936. DeGolyer and MacNaughton does not have any financial interest, including stock ownership, in
GeoPark. Our fees were not contingent on the results of our evaluation. This letter report has been prepared at the request of
GeoPark. DeGolyer and MacNaughton has used all assumptions, data, procedures, and methods that it considers necessary and appropriate
to prepare this report.





















| | Submitted,                             
| | ---------------------------------------
| |                                        
| | /s/ DeGolyer
and MacNaughton           
| |                                        
| | DeGOLYER and
MacNAUGHTON               
| | Texas Registered Engineering Firm F-716













|       | /s/ Thomas C. Pence     
|------ | ------------------------
|       | Thomas C. Pence, P.E    
|[SEAL] | Senior Vice President   
|       | DeGolyer and MacNaughton










DeGolyer and MacNaughton




CERTIFICATE
of QUALIFICATION



I,
Thomas C. Pence, Petroleum Engineer with DeGolyer and MacNaughton, 5001 Spring Valley Road, Suite 800 East, Dallas, Texas,
75244 U.S.A., hereby certify:



| | 1. | That
                                         I am a Senior Vice President of DeGolyer and MacNaughton, which company did prepare the
                                         letter report addressed to GeoPark dated
                                         April 11, 2017, and that I, as Senior Vice President, was responsible for the preparation
                                         of this letter report.
| | -- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | 2. | That
                                         I attended Texas A&M University, and that I graduated with a Bachelor of Science
                                         degree in Petroleum Engineering in 1982; that I am a Registered Professional Engineer
                                         in the State of Texas; that I am a member of the International Society of Petroleum Engineers
                                         and that I have in excess of 34 years of experience in oil and gas reservoir studies
                                         and reserves evaluations.
| | -- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



















|       | /s/ Thomas C. Pence     
|------ | ------------------------
|       | Thomas C. Pence, P.E    
|[SEAL] | Senior Vice President   
|       | DeGolyer and MacNaughton