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Dear Sirs:

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Sproule International Limited (“Sproule”) has been engaged by Hocol S.A (“Hocol” or the “Company”) to evaluate the proved, probable, and possible reserves in 9 blocks (14 fields) in Colombia, as of December 31, 2021, and to prepare a report as to its findings (the “Report”). The Report is compliant with the United States Securities Exchange Commission (SEC) definitions and disclosure guidelines. Hocol S.A. is a wholly owned subsidiary of Ecopetrol S.A. The Report, completed on January 17, 2022 and presented herein, was prepared for public disclosure by Ecopetrol S.A. in filings made with the SEC in accordance with the disclosure requirements set forth in the SEC regulations.

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Ecopetrol S.A. has represented that the properties evaluated by Sproule for Hocol account for one (1) percent of Ecopetrol’s net total Barrel of Oil Equivalent (“BOE”) proved reserves as of December 31, 2021.

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Estimates of Reserves

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Reserves estimates included in this report are expressed as net oil reserves. Net oil reserves are defined as the portion of the gross reserves to be produced from the 9 blocks (14 fields) evaluated by Sproule after December 31, 2021 attributable to the interests owned by Ecopetrol after deducting all interests owned by others, including royalties in kind. As regulated by the ANH, all royalties associated to the properties reported herein were considered as a cash payment and not deducted from the net gas reserves.

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140 Fourth Avenue SW, Suite 900

Calgary, AB, Canada T2P 3N3

Sproule.com

T +1 403 294 5500 F +1 403 294 5590 TF +1 877 777 6135

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The reserves estimates for the properties  contained herein were obtained using a variety of estimation methods: volumetric, performance, analogy or a combination of performance and volumetric methods. The following table summarizes the approximate percentage of the net reserves estimated by each of these methods.

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Sproule’s estimates of Ecopetrol S.A.’s net proved reserves, attributable to the properties contained in this report, were based on the definitions of proved reserves as promulgated by the SEC and are summarized as follows, expressed in millions of barrels (MMbbl) and millions of cubic feet (MMcf):

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Accuracy and Reliance on Data

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All historical production, revenue and expense data, product prices, and other data that were obtained from the Company were accepted as represented, without further investigation by Sproule. According to the contract, the Company provided all the information required, such as the needed information and documents to ensure that Sproule would be able to complete the consulting services. Sproule is not responsible for the veracity and integrity of the information provided by the Company to execute the consultancy, which has been used in the generation of the evaluation results.

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The accuracy of reserves estimates and associated economic analysis is, in part, a function of the quality and quantity of available data and of engineering and geological interpretation and judgment. Given the data provided at the time this letter was prepared, the estimates presented herein are considered reasonable. However, they should be accepted with the understanding that reservoir and

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financial performance subsequent to the date of the estimates may necessitate revision. These revisions may be material.

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Maintenance, capital, abandonment, decommissioning and reclamation (“ADR”) cost estimates, as supplied by the Company, were accepted by Sproule as represented. No further investigation was undertaken by Sproule.

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Evaluation Standards

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This report has been prepared by Sproule using current geological and engineering knowledge, techniques and computer software. It has been prepared within the Code of Ethics of the Association of Professional Engineers and Geoscientists of Alberta (“APEGA”). This report was prepared in accordance with the guidelines and standards of the PRMS and the SEC regulations.

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Hydrocarbon Prices

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Constant prices were used in the economic evaluation and are based on the unweighted arithmetic average of the first day-of-the month price for each of the 12 months preceding the effective date, as per SEC price parameters guidance. Hocol provided to Sproule the prices to be used in the evaluation. The benchmark prices used in this evaluation are as follows:

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Appropriate adjustments have been made to the constant oil prices to account for quality and transportation. These adjustments have been made and are presented at the field level.

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Gas prices are based on gas sales contracts, and only applies to the sales gas volumes. A summary of the realized prices used in the evaluation was provided in the detailed final report.

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Forward-Looking Statements

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The evaluation process involves modeling to reasonably predict future outcomes. Inherent in the modeling process however are limitations which may indirectly affect the forecast of future events.

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This report contains forward-looking statements including expectations of future production revenues and capital expenditures. Information concerning reserves may also be deemed to be forward- looking as estimates involve the implied assessment that the reserves described can be profitably produced in the future. These statements are based on current expectations that involve a number of risks and uncertainties, which could cause actual results to differ from those anticipated. These

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risks include, but are not limited to: the underlying risks of the oil and gas industry (i.e., corporate commitment, regulatory approval, operational risks in development, exploration and production); potential delays or changes in plans with respect to exploration or development projects or capital expenditures; the uncertainty of reserves estimations; the uncertainty of estimates and projections relating to production; costs and expenses; health, safety and environmental factors; commodity prices; and exchange rate fluctuation.

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Standards of Independence and Professional Qualifications

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Sproule is an independent petroleum engineering consulting firm that has been providing petroleum engineering consulting services in Canada and throughout the world since 1950. Our head office is located in Calgary, Alberta, Canada. In addition to having technical offices in Mexico City, Mexico, and The Hague, Netherlands, we also have commercial representation offices in Rio de Janeiro, Brazil.

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Sproule does not have any financial interest, including stock ownership, in Ecopetrol S.A. The fees paid by the Company to Sproule, nor the award of the contract to complete this work, were not contingent on the results of the evaluation.

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The professional qualifications of the technical person primarily responsible for reviewing and approving the reserves evaluation of the properties contained herein, are included as an attachment to this letter.

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P:\HOCOL SA 110861 2021 Res\Project Management\Due Diligence\Rev 4\.2 for Ecopetrol.docx