Exhibit 99.2






Four
      Oaks Place1300
      Post Oak Boulevard, Suite 1000Houston,
      Texas 77056Telephone:
                (713)
      850-9955Facsimile:
                (713)
      850-9966Email:
                gcah@gaffney-cline.com





SOP/bgh/C1774.00/gcah.133.10
            June
      9, 2010





Mr. Oscar
Valbuena Amaris


Director
de Control de Reservas


Ecopetrol,
S. A.


Edificio
Principal, Piso 7


Bogota,
Colombia


Reserve
Audit for Forty Two Fields in Colombia


As
well as Ecopetrol’s Participation in PetroTech Peruana SA (SAVIA)




Dear Mr.
Valbuena Amaris:




At the
request of Ecopetrol, S.A. (Ecopetrol), a participant in forty two fields in the
Inferior, Middle and Upper Magdalena Valley, Catatumbo and Putumayo Basins in
Colombia; as well as Ecopetrol’s participation on Petro-Tech Peruana (renamed
Savia SA), Gaffney, Cline & Associates (GCA) has conducted an independent
audit examination as of December 31, 2009 (the “effective date of our report”)
of the liquid hydrocarbons and natural gas reserves for the fields mentioned
above.  On the basis of technical and other information made available
to us concerning these property units, we provided a reserve statement given in
our report to Ecopetrol dated January 15, 2010; the results of which are shown
in the table below. Total Proved Reserves, net to Ecopetrol interest, represent
19% of Ecopetrol’s total Proved Reserves on a barrel oil equivalent (BOE) basis.
This proportionate share was supplied by Ecopetrol.




Statement
of Hydrocarbon Reserves Volumes


Forty
Two Fields in Colombia


As
of December 31, 2009




Gross
      (100%) Field Volumes
                                  
                                  
                                  Reserves
      Net to Ecopetrol
                                    InterestReserves
      Category
                                  
                                  Liquids
                                    (MMstb)
                                  
                                  
                                  Gas
                                    (Bscf)
                                  
                                  
                                  Liquids
                                    (MMstb)
                                  
                                  
                                  Gas
                                    (Bscf)ProvedDeveloped
      Producing
                                  
                                  
                                  273.2
                                  
                                  
                                  
                                  92.9
                                  
                                  
                                  
                                  162.8
                                  
                                  
                                  
                                  37.5Developed
      Non-Producing
                                  
                                  
                                  9.8
                                  
                                  
                                  
                                  0.1
                                  
                                  
                                  
                                  6.6
                                  
                                  
                                  
                                  0.1Total
      Developed
                                  
                                  
                                  283.0
                                  
                                  
                                  
                                  93.0
                                  
                                  
                                  
                                  169.4
                                  
                                  
                                  
                                  37.6Undeveloped
                                  
                                  
                                  193.3
                                  
                                  
                                  
                                  18.9
                                  
                                  
                                  
                                  117.4
                                  
                                  
                                  
                                  10.2Total
      Proved
                                  
                                  
                                  476.3
                                  
                                  
                                  
                                  111.9
                                  
                                  
                                  
                                  286.8
                                  
                                  
                                  
                                  47.8





GCA
prepared its reserve statement in accordance with the definitions of reserves
set out in 17 CFR Part 210 Rule 4-10(a) of the United States Securities and
Exchange Commission (the “SEC”) and the disclosure guidelines contained in the
SEC Final Rule titled “Modernization of Oil and Gas
Reporting” dated December 31, 2008 and effective as of January 1, 2010
(the “2010 Oil and Gas SEC Final Rule”).




UNITED
      KINGDOM
              
              UNITED
      STATES
              
              SINGAPORE
              
              AUSTRALIA
              
              ARGENTINA
              
              BRAZIL
              
              KAZAKHSTAN
              
              RUSSIA
              
              UAE








Gaffney,
      Cline & AssociatesSOP/bgh/C1774.00/gcah.133.10Ecopetrol,
      S. A.June
      9, 2010Page
      2




Hydrocarbon
liquid volumes represent crude oil and condensate, natural gasoline and LPG
estimated to be recovered during field separation and plant processing, and are
reported in millions of stock tank barrels (MMstb).  Natural gas
volumes represent expected gas sales, and are reported in billions (109) of
cubic feet (Bscf) at standard conditions of 14.7 psia and 60 degrees
Fahrenheit.  These volumes have been reduced for fuel usage in the
field.  Royalties payable to the State have been deducted from
reported net volumes.




It is
GCA’s opinion that the estimates of total remaining recoverable hydrocarbon
liquid and gas volumes at December 31, 2009, are, in the aggregate, reasonable
and have been prepared in accordance with the definitions for reserves set out
in 17 CFR Part 210 Rule 4-10(a) of the SEC and the 2010 Oil and Gas SEC Final
Rule.




This
assessment has been conducted within the context of GCA’s understanding of
Ecopetrol’s petroleum property rights as represented by Ecopetrol’s
management.  GCA is not in a position to attest to property title,
financial interest relationships or encumbrances thereon for any part of the
appraised properties or interests.




This
audit examination was based on reserve estimates and other information provided
by Ecopetrol to GCA through December 2009, and included such tests, procedures
and adjustments as were considered necessary under the circumstances to prepare
this report.  Field data and information provided by Ecopetrol varies
from field to field, Ecopetrol provided production data sets, depending on the
field, up to August, September, October, November, or December
2009.  All questions that arose during the course of the audit process
were resolved to our satisfaction.  The reported hydrocarbon reserve
is an estimate based on professional engineering judgment and is subject to
future revisions, upwards or downwards, as a result of future operations or as
additional information becomes available. Technical information and comments
related to the methodology followed to audit the reserves volumes for each one
of the fields, is presented in separate individual reports.  As these
reports are quite extensive and detailed, the significant points of the work
performed are summarized below.




In order
to confirm estimates of petroleum initially in place, the structural and
stratigraphic descriptions of the accumulations, various reservoir limits, rock
petrophysical parameters and reservoir fluid properties were reviewed checked
for reasonableness and/or modified as appropriate  based on
information and data supplied by Ecopetrol.  Reservoir and individual
well performance was analyzed in order to assess the predominant reservoir drive
mechanisms currently active in the fields and those expected to affect the
future production performance.




Recoverable
volume estimates as derived from profiles of expected future performance were
checked for consistency with the development plans provided by Ecopetrol and
verified on the basis of individual well decline analysis, typical well
performance models, material balance calculations, reservoir simulation results,
analogies, etc. as appropriate to the available information and category of the
reserves.




Gross
reserves and those net to Ecopetrol’s interests were verified on the basis of
the fiscal and contractual terms applicable in each case.







Gaffney,
      Cline & AssociatesSOP/bgh/C1774.00/gcah.133.10Ecopetrol,
      S. A.June
      9, 2010Page
      3




The
commerciality and economic tests for the December 31, 2009 Reserves volumes were
based on a constant reference price for West Texas Intermediate (WTI) crude;
these prices were obtained as the un-weighted average of the oil price the first
day of each month, corrected for location and quality to a wellhead price for
each field.  Sales gas and plant product prices were advised by
Ecopetrol according to existing contracts and/or regulations.




Future
capital costs for the fields were derived from development program forecasts
prepared by field operators.  Recent historical operating expense data
were utilized as the basis for operating cost projections.  GCA has
found that sufficient capital investments and operating expenses have been
projected by the operators to produce the projected volumes.




GCA
believes the assumptions, data, methods, and procedures used in its audit are
appropriate for the purposes of this reserve statement.




There are
numerous uncertainties inherent in estimating reserves and resources, and in
projecting future production, development expenditures, operating expenses and
cash flows.  Oil and gas reserve engineering and resource assessment
must be recognized as a subjective process of estimating subsurface
accumulations of oil and gas that cannot be measured in an exact
way.  Estimates of oil and gas reserves or resources prepared by other
parties may differ, perhaps materially, from those contained within this
report.  The accuracy of any Reserve or Resource estimate is a
function of the quality of the available data and of engineering and geological
interpretation.  Results of drilling, testing and production that
post-date the preparation of the estimates may justify revisions, some or all of
which may be material.  Accordingly, Reserve and Resource estimates
are often different from the quantities of oil and gas that are ultimately
recovered, and the timing and cost of those volumes that are recovered may vary
from that assumed.




* * * *
*




For this
assignment, GCA served as independent reserve auditors.  The firm’s
employees have no direct or indirect interest holding in
Ecopetrol.  GCA’s remuneration was not in any way contingent on
reported reserve estimates.  No representations are made herein in
respect of property title or encumbrances thereon.  This report has
been prepared for Ecopetrol and Ecopetrol will obtain GCA’s approval for the use
and context of the use of any results, statements or opinions expressed to
Ecopetrol, which are attributed to GCA.  Such approval shall include,
but not be confined to, statements or references in documents of a public or
semi-public nature such as loan agreements, prospectuses, reserve statements,
press releases, etc.




Very
truly yours,




GAFFNEY,
CLINE & ASSOCIATES, INC.





/s/ David K. MorganDavid
      K. MorganSenior
      Technical Manager




Attachment


Appendix
                  I:
                  Statement
      of
Qualifications





Gaffney,
      Cline &
Associates


APPENDIX
I:





Statement
of Qualifications








Gaffney,
      Cline &
Associates





Statement
of Qualifications





One of
GCA’s Senior Technical Mangers was responsible for overseeing the preparation of
the audit.  This manager has over 40 years of diversified
international industry experience mainly in reservoir-engineering, geology,
reserves estimates, project development, economics and training in the
assessment, classification and reporting of reserves and
resources.  Over the past 5 years he has been responsible for project
review and oversight for GCA’s Houston office as it pertains to exploration and
production activities including the reserves audits conducted on behalf of
Ecopetrol, S. A.  He is a member of the Society of Petroleum Engineers
(SPE) and holds a petroleum engineering degree from Marietta
College.