As filed with the Securities and Exchange Commission on April 5, 2019

March 31, 2020

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 20-F
ANNUAL REPORT PURSUANT TO
SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 20182019

Commission file number: 001-34175

ECOPETROL S.A.
(Exact name of Registrant as specified in its charter)

N/AN /A
(Translation of Registrant’s name into English)

REPUBLIC OF COLOMBIA
(Jurisdiction of incorporation or organization)

Carrera 13 No. 36 – 24

BOGOTA – COLOMBIA
(Address of principal executive offices)
Tel. (571) 234 4000

Andrés Felipe SánchezLina María Contreras Mora

Investor Relations Officer
investors@ecopetrol.com.co
Tel. (571) 234 5190
Carrera 13 N.36-24 Piso 7
Bogota, Colombia
(Name, Telephone, E-Mail and/or Facsimile number and Address of Company Contact Person)

Securities registered or to be registered pursuant to Section 12(b) of the Act.

Securities registered or to be registered pursuant to Section 12(g) of the Act: None

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: None

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

41,116,694,690 Ecopetrol common shares, par value COP$609 per share

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

x Yes¨ No

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

¨ Yesx No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

x Yes¨No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

x Yes¨ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or an emerging growth company. See definition of “large accelerated filer,” “accelerated filer,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to Section 13(a) of the Exchange Act.¨

† The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow:

¨ Item 17¨ Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company
(as defined in Rule 12b-2 of the Exchange Act).

¨ Yesx No

Annual Report on Form 20-F 20182019

Table of Contents

1.1About This Report

We file our Annual Report on Form 20-F and other information with the U.S. Securities and Exchange Commission.

We file reports, including annual reports on Form 20-F, and other information with the SEC pursuant to the rules and regulations of the SEC that apply to foreign private issuers. The materials included in this annual report on Form 20-F may be downloaded at the SEC’s website: http://www.sec.gov. Any filings we make are also available to the public over the Internet at the SEC’s website at www.sec.gov and at our website at www.ecopetrol.com.co. (This URL is intended to be an inactive textual reference only. It is not intended to be an active hyperlink to our website. The information on our website, which might be accessible through a hyperlink resulting from this URL, is not and shall not be deemed to be incorporated into this annual report.)

Unless the context otherwise requires, the terms “Ecopetrol,” “we,” “us,” “our,” “Ecopetrol Group,” or the “Company” are used in this annual report to refer to Ecopetrol S.A. and its subsidiaries on a consolidated basis.

For purposes of the sectionBusiness Overview—Exploration and Production, “we” refers to Ecopetrol S.A., its subsidiaries and the partnerships in which Ecopetrol has an interest.

References to the Nation in this annual report relate to the Republic of Colombia (“Colombia”)(Colombia), our controlling shareholder. References made to the Colombian government or the Government correspond to the executive branch including the President of Colombia, the ministries and other governmental agencies responsible for regulating our business.

1.2Forward-looking Statements

This annual report on Form 20-F contains forward-looking statements within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are not based on historical facts and reflect our expectations for future events and results. Most facts are uncertain because of their nature. Words such as “anticipate,” “believe,” “could,” “estimate,” “expect,” “should,” “plan,” “potential,” “predicts,” “prognosticate,” “project,” “target,” “achieve” and “intend,” among other similar expressions, are understood as forward-looking statements. We have made forward-looking statements that address, among other things:

Our forward-looking statements and sensitivity analysis are not guarantees of future performance and are subject to assumptions that may prove incorrect and to risks and uncertainties that are difficult to predict. Actual results could differ materially from those expressed or forecasted in any forward-looking statements as a result of a variety of factors. These factors may include, but are not limited to, the following:

All forward-looking statements attributed to us are qualified in their entirety by this cautionary statement. We undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information or for any other reason. Accordingly, readers should not place undue reliance on the forward-looking statements.

1.3Selected Financial and Operating Data

The following table sets forth, for the periods and at the dates indicated, our selected historical financial and certain key operating data. The selected financial data has been derived from and should be read in conjunction with, and is qualified in its entirety by reference to, our consolidated audited financial statements, presented in Colombian Pesos.

Table 1 – Selected Operating Data

Financial Information

International Financial Reporting Standards (“IFRS”)(IFRS)

(Expressed in millions of Colombian Pesos, except for the net income per share and net operating income per share, which are expressed in Colombian Pesos)

Table 2 – Selected Financial Data

Our consolidated financial statements for the years ended December 31, 2014, 2015, 2016, 2017, 2018 and 20182019 were prepared in accordance with IFRS as issued by IASB. References in this annual report to IFRS mean IFRS as issued by the IASB. Our date of transition to IFRS was January 1, 2014. Our consolidated financial statements for the year ended December 31, 2015 were our first set of consolidated financial statements prepared in accordance with IFRS.

IFRS differs in certain significant aspects from the current reporting standards as in effect in Colombia (“Colombian IFRS”)(Colombian IFRS), which is the accounting standard we use for local reporting purposes. As a result, our financial information presented under IFRS is not directly comparable to our financial information presented under Colombian IFRS. For a description of the differences between Colombian IFRS and IFRS, see sectionFinancial Review—Review—Summary of Differences between Internal Reporting Policies and IFRS.

Our consolidated financial statements were consolidated line by line and all transactions and balances between subsidiaries have been eliminated. These financial statements include the financial results of all subsidiary companies controlled, directly or indirectly, by Ecopetrol S.A. See Exhibit 1 –Consolidated companies, associates and joint ventures, to our consolidated financial statements included in this annual report.report.

As indicated in IFRS 10 “Consolidated Financial Statements”Statements,” we must present our financial information on a consolidated basis as if we were a single entity, combining the financial statements of Ecopetrol S.A. and its subsidiaries line by line, adding assets, liabilities, shareholder’s equity, revenues and expenses of similar nature, removing the reciprocal items among members of the Ecopetrol Group (“Ecopetrol Group”(Ecopetrol Group or “EG”)EG) and recognizing non-controlling interest. We present our operating information on a consolidated basis in accordance with IFRS.

The regulations of the SEC do not require foreign private issuers that prepare their financial statements on the basis of IFRS to reconcile such financial statements to U.S. GAAP. Accordingly, while we have in the past reconciled our consolidated financial statements prepared in accordance with Colombian Government Entity GAAP to U.S. GAAP, these reconciliations have not been presented in our filings to the SEC since 2015. We do continue to provide the disclosure required under the U.S. Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 932 “Extractive Activities—Oil and Gas” (which we refer to as ASC Topic 932), as this is required, regardless of the basis of accounting on which we prepare our financial statements.

In this annual report, references to “US$” or “U.S. dollars” are to United States dollars and references to “COP$” “Colombian Peso” or “Colombian Pesos” are to Colombian Pesos, the Ecopetrol Group’s functional and presentation currency under which we prepare our consolidated financial statements. This annual report translates certain Colombian Peso amounts into U.S. dollars at specified rates solely for the convenience of the reader. Unless otherwise indicated, such Colombian Peso amounts have been translated at the rate of COP$2,956.553,282 per US$1.00, which corresponds to theTasa Representativa Promedio del Mercado (TRM), or Average Representative Market Exchange Rate, for 2018.2019. Such conversion should not be construed as a representation that the Colombian Peso amounts correspond to, or have been or could be converted into, U.S. dollars at that rate or any other rate. On April 1, 2019,March27, 2020, the Representative Market Exchange Rate was COP$3,174.793,996 per US$1.00.

Certain figures shown in this annual report have been subject to rounding adjustments, and, accordingly, certain totals may therefore not precisely equal the sum of the numbers presented. In this annual report a billion is equal to one with nine zeros.

After experiencingThe US-China trade war escalated in 2019 and increased average tariffs between the two nations (U.S. tariffs to China rose from 12.0% to 21.0%, and Chinese tariffs to the U.S. from 16.5% to 21.1% in each case from 2018 to 2019), affecting global confidence. Global industrial production entered a gradual recovery during the first half of 2018downturn, and reachingworld trade stagnated with most countries worldwide recording a peak in October, the ICE Brent price suffered a downward trendslowdown in the latter partgrowth of 2018. The expectationtheir economies. In 2019, these factors led to a 0.75 million barrels of weaker economic growth for 2019 and a mismatch of supply and demand of crude played a fundamental role in this trend. The US government imposed sanctions on Iran in August of 2018, announcing the goal of reducing Iranian crude and condensate exports to almost zero. This created an expectation of a tight oil market during the latter part of 2018. However, several factors did not support a strong market outlook: refining margins weakened, inventories began to pile up and production from the US, Saudi Arabia and Russia ramped up, all at the same time. Additionally, the US government provided waivers to Iranian crude importers. As a reaction to low crude prices, the OPEC+ countries agreed to cut production in order to rebalance the crude market. On the demand side, weaker economicequivalent per day (mmboepd) growth in China and Europe did not favor crude oil consumption.demand, the lowest growth rate since 2012 when demand increased by 0.60 mmboepd.

According to estimatesWorld oil supply remained stable in 2019. While the supply of those outside the Organization of the Energy Information Administration (“EIA”),Petroleum Exporting Countries (OPEC) increased by 1.94 mmboepd in 2018 global consumption of petroleum and other liquids fuels grew by 1.4 mmboepd while Non-OPEC petroleum and other liquid fuels supply grew by 2.5 mmboepd. On the other hand, OPEC reduced its production by 0.09 mmboepd,2019, mainly due to unplannedhigher production in the U.S. (1.62 mmboepd) and Brazil (0.23 mmboepd), the supply from OPEC countries fell by 2.10 mmboepd. In addition to production declines in Saudi Arabia, the decrease in total OPEC output was largely driven by falling production in Venezuela and Iran due, in part, to U.S. sanctions. Crude oil production in Venezuela averaged 0.82 mmboepd in 2019, a decline of 0.57 mmboepd as compared to 2018. In 2019, Iranian crude oil disruptions whichproduction decreased by 1.21 mmboepd as compared to 2018.

In conclusion, global oil markets were roughly balanced in December amounted2019, as global oil supply declined slightly, and global oil consumption grew at the smallest rate since 2009. However, market pessimism increased in 2019 largely due to 2.2 mmboepdtrade war fears and a global slowdown, pushing down the price of oil. Brent averaged US$64/Bl in Libya and Nigeria, Iranian sanctions and decreasing production in Venezuela.2019, down from a 2018 average of US$72/Bl.

Graph 1 – Supply/Demand Balance vs ICE Brent Price Evolution

Source:EIA: Short term EnergyEnergy Outlook (January 15, 2019)

During 2020, international reference prices have been impacted due to the disagreement on production cuts between the Organization of the Petroleum Exporting Countries (OPEC) and Russia, global and regional economic and political developments in the OPEC, and its capacity and decision to increase production levels to gain market share.

Although international oil prices and global demand and supply dynamics are significant factors affecting our business and financial condition, Colombia’s local economic factors have also influenced, and could continue to influence our performance, given that we conduct most of our business in Colombia.

The performance of Colombia’s gross domestic product (GDP) is one of the main drivers of fuel consumption in Colombia.consumption. According to the National Administrative Department of Statistics (DANE for its acronym in Spanish)Spanish acronym), during 20182019 Colombia’s GDP grew 2.7%by3.3% in real terms, as compared to 2017.2018. The sectors with the greatest growth rates were retail, manufacturingfinancial services, and state defense spendingpublic administration, which had the largest contribution to national GDP. On the other hand, agricultural and cattle activitiesconstruction had the worst performance.

Local sales of liquid fuels(LPG, diesel, jet and gasoline)increased by 1.3%,4% in 2019, boosted by increased demand for dieselgasoline and jet fuel.diesel.

Natural gas demand in Colombia grewdecreased by 5.1%1.7% in 2019 as compared to 2018 due to higherlower demand from natural gas fired power plants and from non-thermal demand, mainly for household consumption.plants.

2.1Our Corporate Strategy

2.1.1The Ecopetrol Group’s 2020 - 2022 Business Plan

Ecopetrol’s 2019 – 2021 (the “Business Plan”) maintainsPlan) is aligned with the strategic priorities set forthof achieving profitable and sustainable growth, using strict capital discipline and cash flow protection, taking into consideration the challenges posed by energy transition, climate change, respect for the environment and biodiversity, the protection and responsible use of water, and the inclusion of an innovation and technology component, leveraging the integrated value generation for the Group.

The Plan includes investments between US$13 and US$17 billion, most of which will be invested in the previous 2020 plan: we continue to prioritize profitableColombia, aimed at continuing reserves and production growth, underpinned by strict capital disciplinethe search and continued focus on cost efficiencydevelopment of investment opportunities to leverage portfolio diversification, and cash flow generation. The plan seeks to maximize value generation for our shareholders with continued focus on our incumbent position in Colombia, ensuring sustainability, competitiveness and profitability.

Among other matters, the Business Plan calls for achieving the following targets by the end of 2021: (i) organic production levels between 750-770 mboed, (ii) optimum throughputcontinuity of the integrated refining system at a level between 370-400 mbpd, (iii) increasing transported volumes in lineoperations. Furthermore, the Plan provides for increased operational sustainability with the country’s production, (iv) investing approximately US$12-15 billion during the periodspecific goals of decarbonization, increased use of renewable energy and (v) maintaining a robust cash position and optimal leverage levels.digital transformation. The Business Plan is based on a referenceBrent price of US$65/bl.57/Bl.

GrowthInvestments in reserves and production will be supported by four levers: (i)growth (58%) are focused on continuing the growthprofitable development of our recovery factorsexisting assets and underlying hydrocarbonsaddressing the transition to gas. Investments in placeoperational continuity (26%) are aimed at preserving the value of the assets and providing reliability and integrity to the operation, and the remaining (16%) of investments will boost innovation and technology and decarbonization goals.

Some of the most relevant operational goals of the Plan are expected to: (i) reach organic production levels of between 745 - 800 thousand barrels of oil equivalent per day, (ii) maintain the replacement rate of organic reserves above 100%, without price effect, (iii) realize throughput between 370 - 420 thousand barrels per day for the integrated refining system, (iv) achieve between 1.10 - 1.25 million barrels per day of volumes transported, in existingline with the expected country’s production and demand for liquid fuels, (v) reduce emissions between 1.8 and 2.0 million metric tons of carbon dioxide equivalent (MmtCO2e) in 2020 and (vi) install approximately 300 Megawatts of renewable energy sources.

Upstream

The Plan allocates 83% of total investments to the upstream segment, prioritizing the development of the Group’s position in strategic assets such as thePiedemonte and Rubiales fields (ii)as well as others in the diversification of our exploration portfolio in Colombia, (iii)Middle Magdalena Valley and key regions such as Brazil and the internationalization of our operations through both organic and inorganic means, and (iv)Permian Basin. Furthermore, the appraisalmaturation and development of identified unconventional hydrocarbon potential in Colombia.

We estimate that by 2021 hydrocarbons originally in place (HCIIP) associated to our assetsimproved recovery activities will continue. The Plan allocates 72% of upstream investments on projects in Colombia while the remainder will be approximately 60 billion barrels compared to 55 billion barrels as of the end of 2018. This increase is expected to be supported by seismic reprocessing, reassessments of reservoirs and drilling of advanced wells, among others. Additionally, the enhanced program is expected to continue to leverage our reserve and production growth.

Growthinvested in the exploratory portfolio in Colombia will prioritize the incorporation of short cycle resources through the strengthening of the near field exploration activity in Colombia, mainly in the Llanos and Middle Magdalena basins. Furthermore, we seek to expand our presence in high potential under-explored basins, such as Putumayo and Piedemonte, andfurther developing the potential of our operations in the offshore Caribbean.Group's international operations.

The internationalization lever seeks to develop and maximize the potential of the position we have built in Brazil, the U.S. Gulf Mexico and Mexico. In addition, we expect to continue assessing business opportunities associated with unconventional hydrocarbon basins in the United States and other mergers and acquisition opportunities in those geographies.

We have identified unconventional hydrocarbons potential in two basins in Colombia of approximately 10 tera cubic feet of gas and between 4 and 7 billion barrels of crude. In our investment plan described below, we are allocating US$500 million for the development of pilot programs between 2019 and 2021, subject to government approval. If successful, we would then move to the commercial development of these pilots after 2021.

Our sustainability and growth are also leveraged in the concept of integration of our different segments.

We expect our midstream segment (or “transportation and logistics segment”) to continue being an important cash generator. In order to do so, the Business Plan calls for, among others, the segment to focus on improving efficiencies and synergies in our transportation system and pursuing investment opportunities in product pipelines given the increase in demand for fuels in Colombia. The Business Plan is currently projecting that our transport systems will move between 1.10-1.25 million barrels of oil and products per day during the period.

In ourterms of exploration, the Plan provides for drilling more than 30 exploratory wells located in the most relevant basins, focused mostly in Colombia and implementing an important seismic survey program. Additionally, the Group expects to continue with the evaluation and development of the offshore gas discoveries made in the Colombian Caribbean through investments totaling US$200 million.

In relation to unconventional reservoirs, the maturation of the initiatives associated with the Comprehensive Research Pilot Project (Proyectos Piloto de Investigación Integral or PPII as per its Spanish acronym) in the Middle Magdalena Valley Basin will continue, and development activities in the Permian Basin in Texas increase.

Downstream

The Plan allocates 11% of investments to the downstream segment, (or “refining, petrochemicals, and biofuels segment”), the Business Plan focusesfocusing on the use and optimization of the current infrastructure in orderinfrastructure. To this end, we plan to achieve an expected refining throughput between 370-400 mbpdconduct major maintenance and an expectedtechnological updates at the Cartagena and Barrancabermeja refineries as well as implement the CartagenaRefinery’s Original Crude Unit interconnection project. We also plan to expand the Esenttia plant by 70 thousand tons of polypropylene per year. A gross refining margin of between US$12-15/bl, subject10 - US$15 per barrel is expected, with periods of significant volatility.

In an effort to market conditions.move forward with the production of cleaner fuels for the country, the investments made during the 2020 - 2022 period will consolidate the quality of domestic diesel to between 10 to 15 ppm of sulphur and reduce the sulphur in gasoline to a maximum of 50 ppm. Moreover, we anticipate initiating a project designed to reach levels below 10 ppm in both fuels in the medium term. We expectalready report this quality level for domestic diesel, including the diesel used by mass transport systems such asTransmilenio in Bogotá.

Midstream

The Plan includes allocating 5% of investments to achieve this (i) throughsegment, focused on improving efficiency and synergies in the incorporation of synergies between the Barrancabermeja and Cartagena refineries and (ii) bytransportation system as well as capturing marketinvestment opportunities in multi-purpose pipelines associated with the implementation of the International Convention for the Prevention of Pollution from Ships (Marpol), which favors the use of fuels with lower sulfur contentincrease in maritime transport. Additionally, asdomestic fuel demand. To this end, we did in 2018, we expectforesee investments totaling US$300 million. This segment is expected to continue delivering low sulfur diesel of 20 parts per million (ppm) and gasoline of 100 ppm versus the Colombian regulation of 50 ppm and 300 ppm, respectively.to be an important cash generator.

Following the implementation of our transformation program in 2015, we have accumulated approximately US$3.3 billion in efficiencies to date. Our Business Plan is focused on continuing this trend. We expect to capture savings of approximately US$1.45-2.0 billion between 2019Technology and 2021, particularly: (i) capital expenditure efficiencies, (ii) revenue and margin optimization and (iii) operating expenditure efficiencies.Innovation

In terms of sustainability,technology, our efforts will focus on realizing the Businessfeasibility of enhanced oil recovery and unconventional hydrocarbons projects in an effective, environmentally and socially sustainable manner, increasing flexibility and logistical efficiency for the transportation of heavy crudes and increasing energy efficiency, among others. Additionally, we plan to complete the ten key projects on our digital agenda that seek to maximize production, improve the commercialization and refining margin, and digitize financial management.

Emission reduction and water management

In line with the Group’s objectives of reducing the carbon emissions associated with its operations, as well as reducing the vulnerability of its operation and infrastructure to climate change, the Plan callsallocates between US$320 and US$430 million for integralinvestments in projects that help reduce carbon emissions between 200 and 400 kilotons of carbon dioxide equivalents (KtCO2e), in order to reach an annual reduction of between 1.8 and 2.0 million of tons of carbon dioxide equivalents (MtCO2e) in 2022. 

In order to enhance integrated water management, wastewater reuse, water security and water governance, the protection of biodiversity and a continued focus on climate change, among others, all within the framework of the United Nations Sustainable Development Goals 2030. We expect to invest approximately COP$2 trillion in socio-environmental projects between 2019 and 2021. We are also seeking to reduce our energy costs by US $100 million by 2021 and increase our investments in renewable energy sources through the incorporation of 60 MW of renewable photovoltaic energy to our energy matrix, which already has 43 MW of biomass generation.

We currently expect the Business Plan to requireallocates investments of between US$12-15 billion during100 and US$150 million in wastewater treatment and final water disposal wells and to provide potable water and sanitation to 900,000 in 40 prioritized municipalities.

Social and Environmental Investment

The Plan expects to allocate between US$350 and US$400 million in funds to our socio-environmental program, designed to help close socioeconomic gaps in Colombia and boost sustainable community development and wellbeing. The priority areas for the 2019-2021 period, of which approximately 82% would be allocated to the upstream segment, 8% to the midstream segment, 7% to the downstream segmentsocio-environmental investment program are public and 3% to other. These investments exclude inorganic growth opportunities, which if materialized, could be financed through cash from operations.community infrastructure, public services, education, sports and health, rural development and business entrepreneurship.

The Business Plan seeks to maintain leverageleveraging metrics to help us preserve ourin line with the Company’s investment grade rating while allowing flexibility for specific optimizations of our capital structure during the period.and competitive vis-à-vis industry peers.

2.1.22019 InvestmentThe Plan emphasizes Ecopetrol's commitment to a safe and sustainable operation, while protecting the environment and the communities in the areas where it operates, and ensuring the satisfaction of its employees, conditions that will help create shared prosperity and constructive dialogue with all its stakeholders.

In November 2018,2019, the Board of Directors approved between US$3.54.5 and US$4.05.5 billion for the 20192020 investment plan.plan at US$57/Bl Brent. The Ecopetrol Group plans to produce between 720745 and 730760 thousand barrels of oil equivalent per day during 2019. 2020. Ecopetrol expects to allocate 78% percent of these investments to projects in Colombia and the remainder to positioning and developing the Ecopetrol Group’s operations in the United States, Mexico and Brazil.

OnMarch 16, 2020, Ecopetrol announced a set of actions to address current challenging market conditions, which have resulted, among other matters, in a 60% decline in the Brent crude price as compared to the end of 2019, due to external shocks including the strong increase in the supply of oil and the spread of COVID-19. These measures are part of a phased intervention plan that aims for the Company to adapt in a timely and orderly manner to changing market conditions.

The first stage of this plan includes the following actions:

The production target for 2020 set forth above remains unchanged as of phase one, between 745 - 760 mboed. See the section entitledTrend Analysis and Sensitivity Analysis—Trend Analysis for further information.

Ecopetrol will continue to monitor market developments to determine the need to launch subsequent stages of the intervention plan, seeking to optimize the balance between decisive responses under current market conditions and preservation the Company's long-term value.

The table below sets forth the details of the initial investment plan per business segment.segment announced in November 2019 (which has now been modified as described above):

Table 3 – 20192020 Investment Plan⁽¹⁾

Exploration

In the exploration, segment, US$430-US$490 millioninvestment has been allocated mainly to the evaluation and appraisal of discoveries and ongoing exploration activity of Ecopetrol S.A. (approximately 44%35%), Hocol S.A. (“Hocol”)(Hocol) (approximately 12%9%), Ecopetrol America Inc.LLC (approximately 1%2%), ECP Hidrocarburos Mexico (approximately 7%), Ecopetrol Costa Afuera (approximately 3%) and Ecopetrol Brazil (approximately 33%47%).

Production

In the production segment, US$2,385-US$2,725 millioninvestment has been allocated mainly to the executiondevelopment of development and incremental production projects of Ecopetrol S.A. (approximately 91%75%) primarily at Castilla, Rubiales, Chichimene, Apiay-Suria, Yariguí-Cantagallo, La Cira-Infantas,Llanito, Casabe, Piedemonte and Quifa. We haveCaño Sur fields. In addition, Ecopetrol plans to spend approximately 19% of the funds allocated in the production investment plan in the Permian project as described below. Ecopetrol also has allocated funds for ourits affiliates and subsidiaries as follows: approximately 3%2% for the development, operation and maintenance of fields of Ecopetrol America Inc.LLC in the U.S. Gulf of Mexico and approximately 5%4% to Hocol, approximately 1% to Equion and Savia.Hocol.

Midstream

In the midstream segment, US$240-US$275 million hasresources have been allocated to investments focused onimprove system and operational integrity. The segment seeks to strengthen its profitability by means of higher transported volumes through oil and multi-purpose pipelines and better operating results. These investments are expected to optimize future operating costs due to equipment upgrades and performance improvement.

Downstream

In the downstream segment, investment has been primarily allocated to the Barrancabermeja and Cartagena refineries through initiatives aimed at optimizing maintenance costs, enhancing integrity management, and improving the quality of diesel and gasoline. The segment is seeking a higher efficiency in operations and maintenance practices.

Downstream

In the downstream segment, US$365-US$420 million has been principally allocated to Barrancabermeja refinery and Reficar through initiatives aimed at increasing revenues, enhancing integrity management, improving efficiency and reducing operational costs. The segment is seeking a higher efficiency in operations and maintenance practices in order to maximize the value of the existing assets.

Environmental, Social and Governance (ESG) and Digital Transformation

Ecopetrol expects to invest US$150 million in energy transition and carbon emission reduction in 2020. The Plan includes funding for the medium-term socio-environmental investment program, with an expected investment ofbetween US$350 and US$400 million for the upcoming three years, aimed at helping close socioeconomic gaps in Colombia and boosting sustainable community development and wellbeing.

To strengthen the digital transformation, Ecopetrol expects to allocate US$91 million in 2020 toward capturing benefits associated with artificial intelligence, blockchain and bot technologies, among others. Ecopetrol expects to invest an additional US$35 million in leveraging new innovation processes, including creating strategic alliances and innovation ecosystems.

3.1Our History

We were formed in 1951 by the Colombian government asEmpresa Colombiana de Petróleos and began operating the crude oil fields at La Cira-Infantas, the oldest Colombian oil field, where production started in 1918, and the pipeline that connected that field with the Barrancabermeja refinery and the port of Cartagena. In 1961, we assumed the direct operation of the Barrancabermeja refinery and continued its transformation into an industrial complex. In 1974, we acquired the Cartagena Refineryrefinery (as defined below), which had been in operation since 1957. Pursuant to Decree 0062 of 1970, we were transformed into a governmental, industrial and commercial company.

In 2003 pursuant to Decree Law 1760, theAgencia Nacional de Hidrocarburos - National Hydrocarbons Agency (the “ANH”)ANH) was created and Ecopetrol’s public role as administrator and regulator of the national hydrocarbons resources was transferred to the ANH. Ecopetrol modified its organic structure and became Ecopetrol S.A., a public stock-holding corporation, one hundred percent state-owned, and continued the development of exploration and production activities in a competitive basis with autonomy over our business decisions. Since 2006, according to Law 1118, we have been evolving from a wholly state-owned entity to a mixed-economy company with private capital. This process has resulted in a substantial change in the legal framework to which we are subject and in the nature of our relationship with the Nation, as our controlling shareholder. As of March 23, 2018, pursuant to our amended bylaws, the duration of the Company is 100 years.

We carried out our initial public offering in November 2007, when our common shares were listed on the Colombian Stock Exchange. Our American Depository Shares (“ADSs”)(ADSs) were listed on the New York Stock Exchange in 2008. Starting in August 2010, our ADSs began trading on the Toronto Stock Exchange (“TSX”)(TSX) under the symbol “ECP.” On February 17, 2016, we announced our application for voluntary delisting from the TSX. On March 25, 2016, our ADR’s were officially delisted from the TSX. On December 7, 2017, we applied to the Alberta Securities Commission and the Ontario Securities Commission to cease our reporting requirements, due to our delisting process. On September 4, 2018, we announced that effective August 29, 2018, we had ceased to be a reporting issuer in each of the provinces of Alberta and Ontario and hence were no longer a reporting issuer in any jurisdiction in Canada. Accordingly, Ecopetrol no longer has any continuous disclosure obligations in Canada.

3.2Our Corporate Structure

We operate in the following business segments: i)(i) Exploration and Production; ii)(ii) Transportation and Logistics; and iii)(iii) Refining, Petrochemicals and Biofuels.

Our subsidiaries, Refinería de Cartagena S.A. (“Reficar”S.A.S. (Reficar or “Cartagena Refinery”)Cartagena Refinery), Cenit Transporte y Logistica de Hidrocarburos S.A.S. (Cenit) and Oleoducto Central S.A. (Ocensa) are significant subsidiaries, as such term is defined under SEC Regulation S-X.

We have a number of directly and indirectly held subsidiaries both in Colombia and abroad. Our subsidiaries are either directly owned by us or indirectly owned by us through one or more of our other subsidiaries. As of December 31, 2018,2019, we have seven directly owned and 2922 indirectly owned subsidiaries.

During 2018,2019, the following changes were made to the Ecopetrol Group’s structure:

Graph 2 – Ecopetrol Corporate Structure

The stock ownership percentage listed refers to Ecopetrol S.A.’s direct and indirect participation. The data in this structure shows neither the whole ownership nor its decimal figures, so they will be used only for information purposes.

The so-called shareholding (Ecopetrol S.A.’s direct participation), affiliated, subsidiary companies are listed, as well as the stock interest of Ecopetrol S.A.’s subordinate companies.

In 2017, Ecopetrol completed the divestment of its stake in Empresa de Energía de Bogotá S.A. E.S.P. EEB for a total of COP$1,124 billion. The operation was carried out in accordance with the procedures defined by the Law 226 of 1995, the Decree 2305 of November 13, 2014, and the Decree 2110 of December 22, 2016.

We currently own 100% of the total outstanding shares of Esenttia. In connection with the review of its long-term strategy, the Board of Directors decided to suspend the 2016 plan to sell Ecopetrol’s shares in Esenttia.

Exhibit 8.1 to this annual report identifies our principal operating subsidiaries, their respective countries of incorporation, and our percentage ownership in each (both directly and indirectly through other subsidiaries).

3.3Our Business

We are a vertically integrated oil and gas company with a presence primarily in Colombia and with activities in Peru, Brazil, Mexico and the U.S. Gulf Coast. The Nation currently controlsowns 88.49% of our voting capital stock. We are among the world’s biggest state-ownedlargest public companies, ranking 300 based on the Forbes Global 2000 Ranking - 2018.2019. We play a key role in the local Colombian hydrocarbon market.

3.4Exploration and Production

Our exploration and production business segment includes exploration, development and production activities in Colombia and abroad. We began local exploration in 1955 and international exploration in 2006. Exploration and production activities are conducted directly by Ecopetrol S.A., and through some of our subsidiaries, as well as through joint ventures with third parties. As of December 31, 2018,2019, we were the largest operator and the largest producer of crude oil and natural gas in Colombia, maintaining the largest acreage exploration position in Colombia.

For purposes of this exploration section, “we” refers to Ecopetrol S.A., its subsidiaries and partnerships in which Ecopetrol has an interest. Unless otherwise stated, all figures are given before deducting royalties.

3.4.1Exploration Activities

Under the framework of the Business Plan, Ecopetrol is aiming to incorporate contingent resources in high reward projects concentrated in: (i) near field exploratory activity, (ii) underexplored basins, such as Putumayo and Piedemonte, (iii) offshore Colombia, and (iv) international areas such as offshore Brazil at Pre-salt Santos, Ceara and Foz de Amazonas basins, the U.S. Gulf of Mexico and Mexico.Offshore Mexico in the Salinas Basin.

Graph 3- Sedimentary Basinsbasins where Ecopetrol executes exploration activities

During 2018,2019, the exploration strategy was directed at leveraging our goal on three working fronts: onshore Colombia, offshore Caribbean, and strengthening and diversifying our exploration overseas.

The Ecopetrol Group was awarded ten exploration blocks by the National Hydrocarbons Agency (ANH) during the 2019 bidding round process. Three of these were awarded to Ecopetrol S.A, the Gua-Off 10 Block located in the Colombian Caribbean offshore and two blocks in the Llanos Basin. The remaining seven blocks were awarded to our subsidiary Hocol.

During 2018,2019, Ecopetrol and its subsidiaries conducted drilling operationsdrilled nineteen (19) wells in twelve exploration wellsColombia, of which fifteen (15) were exploratory (A3/A2) and in fivefour (4) appraisal wells (A1) in Colombia. Of these seventeenSeven (7) wells six were successful, sevennine (9) were plugged and abandoned, and fourthree (3) were under evaluation as of December 31, 2018.2019. This activity was concentrated mainly in the following basins: Eastern Plains (Llanos Orientales),Llanos, Lower Magdalena Valley, Middle Magdalena Valley, Upper Magdalena Valley and foothills.

In terms of onshore Colombia, our exploration efforts were focused on searching for hydrocarbons in mature basins, near-field exploration and areas close to existing production infrastructure.

In offshore activities, we increased our participation from 50% to 100% in theFuerte Sur and Purple Angel blocks (Sinu offshore basin), which were relinquished by Anadarko Petroleum Corporation. In the case of the block Col-5 (Sinu offshore basin), the ANH approved the conversion of a Technical Evaluation Agreement (as defined below) to an Exploration and Production Contract (as defined below), where we have a 100% participation.Piedemonte.

The following table sets forth, for the periods indicated, the number of gross and net productive and dry exploratory wells drilled by us and our joint venture partners, and the exploratory wells drilled by third parties pursuant to sole risk contracts with us.

Table 4 – Exploratory Drilling in Colombia