UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form20-F

(Mark One)

or

or

or

Commission File Number1-15006

(Exact name of Registrant as specified in its charter)

PetroChina Company Limited

(Translation of Registrant’s name into English)

The People’s Republic of China

(Jurisdiction of incorporation or organization)

9 Dongzhimen North Street

Dongcheng District, Beijing 100007

The People’s Republic of China,

(Address of principal executive offices)

Wu EnlaiChai Shouping

Telephone number: 8610(8610) 59982622

Facsimile number: 8610(8610) 62099557

Email address: zxy@petrochina.com.cnzhanghuayi@petrochina.com.cn

Address: 9 Dongzhimen North Street, Dongcheng District, Beijing 100007, The People’s Republic of China

Wei Fang

Telephone number: (852) 2899 2010

Facsimile number: (852) 2899 2390

Email address: hko@petrochina.com.hk

Address: Suite 3705, Tower 2, Lippo Center, 89 Queensway, Hong Kong

(Name, telephone,e-mail and/or facsimile number and address of registrant’s 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

(Title of Class)

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act.

None

(Title of Class)

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:

Indicate by check mark if the registrant is awell-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ☒    No  ☐

If this 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.    Yes  ☐    No  ☒

Note — Checking the box above will not relieve any registrant required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 from their obligations under those Sections.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) or 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.    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 RegulationS-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).    Yes  ☒    No  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” and “emerging growth company” in Rule12b-2 of the Exchange Act:

Large Accelerated Filer  ☒                 AcceleratedFiler  ☐                Non-Accelerated Filer   ☐                Emerging Growth company  ☐

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 Rule12b-2 of the Exchange Act).    Yes  ☐    No  ☒

(APPLICABLE ONLY TO ISSUERS INVOLVED IN BANKRUPTCY PROCEEDINGS DURING THE PRECEDING FIVE YEARS)

Indicate by check mark whether the registrant has filed all documents and reports required to be filed by Sections 12, 13 or 15(d) of the Securities Exchange Act of 1934 subsequent to the distribution of securities under a plan confirmed by a court.    Yes  ☐    No  ☐

Table of Contents

i

ii

CERTAIN TERMS AND CONVENTIONS

Conventions Which Apply to this Annual Report

Unless the context otherwise requires, references in this annual report to:

We publish our consolidated financial statements in Renminbi or RMB. In this annual report, IFRS refers to International Financial Reporting Standards as issued by the International Accounting Standards Board.

Conversion Table

Certain Oil and Gas Terms

Unless the context indicates otherwise, the following terms have the meanings shown below:

structurally higher portions of the reservoir only if geoscience, engineering, or performance data and reliable technology establish the higher contact with reasonable certainty.

References to:

FORWARD-LOOKING STATEMENTS

This annual report contains“forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities and Exchange Act of 1934, as amended. Theseforward-looking statements are, by their nature, subject to significant risks and uncertainties. Theseforward-looking statements include, without limitation, statements relating to:

The words “anticipate”, “believe”, “could”, “estimate”, “expect”, “intend”, “may”, “plan”, “seek”, “will” and “would” and similar expressions, as they related to us, are intended to identify a number of theseforward-looking statements.

By their nature,forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that will occur in the future and are beyond our control. Theforward-looking statements reflect our current views with respect to future events and are not a guarantee of future performance. Actual results may differ materially from information contained in theforward-looking statements as a result of a number of factors, including, without limitation, the risk factors set forth in this annual report and the following:

PART I

Item 1— IDENTITY OF DIRECTORS, SENIOR MANAGEMENT AND ADVISORS

Not applicable. However, see “Item 6 — Directors, Senior Management and Employees — Directors, Senior Management and Supervisors” and “Item 16C — Principal Accountant Fees and Services”.

Item 2— OFFER STATISTICS AND EXPECTED TIMETABLE

Not applicable.

Item 3— KEY INFORMATION

(b) We initially applied IFRS 16 on January 1, 2019 and IFRS 15 and IFRS 9 on January 1, 2018. According to the adopted transition plan, the comparative data has not been restated. For a detailed description of the changes and impacts of these accounting standards, please refer to Note 3 (aa) to our financial statements included in our Form 20-F filed with the SEC on April 29, 2020.

Risk Factors

Our business is primarily subject to various changing competitive, economic, social, political and socialregulatory and other related conditions. Such changing conditions entail certain risks, which are described below.

Risks Related to Macro Economic Conditions

Our operations may be adversely affected by international and domestic economic conditions. As the oil and gas industry is sensitive tomacro-economic trends, oil and gas prices tend to fluctuate along with changes inmacro-economic conditions. We may experience pricing pressure on our refined products in recessionary periods, which would have an adverse effect on our profitability.Changes in macro-economic conditions can affect the demand for certain of our products. These factors may also lead to intensified competition for market share, with consequential potential adverse effects on sales volumes. Inflation may lead to increase in our operating costs. Notwithstanding the measures taken by the PRC government to control inflation, China may experience an increase in inflation in the future and our operating costs may become higher than anticipated. The financial, and economic or political situation may also have a negative impact on third parties with whom we do orbusiness, and may do, business.impact their ability to perform contractual obligations to us. In addition, other factors that affect the macro economy, such as declining population growth rates, geopolitical tensions, conflicts and wars, trade and tariff policies, and major public health events, such as the COVID-19 pandemic, may have an adverse impact on oil and gas and petrochemical industries, including us. Any of these factors may adversely affect our financial condition, results of operations and liquidity.

Risks Related to Competition

The oil, gas and petrochemicals industries are highly competitive. There is strong competition, both within the oil and gas industry and with other industries, in supplying the fuel needs of commercial, industrial and residential markets. In recent years, with the intensive reform of China’s petroleum, refining and chemical, natural gas, LNG, pipelines and refined oils sales industries, we have been facing increasingly intense competition in the exploration, refinery, chemical, sales, and oil and gas service sectors from privately-owned companies, foreign-invested enterprises and other state-owned enterprises that recently entered the refinery, chemical, sales, and oil and gas service sectors.industries. In addition, the rapid development of unconventional oil and gas resources, new energy sources and new products also poses competition with the conventional energy and petrochemical industries. In particular, the booming of the new energy vehicle industry confronts the oil industry with tough challenges. In October 2020, the State Council issued the New Energy Vehicle Industry Development Plan (for 2021-2035), according to which, China expects that the share of new energy vehicles out of total vehicle sales in China to rise to 20% by 2025 and pure electric vehicles to account for the majority of vehicle sales by 2035. We expect to see continued rapid development of the new energy vehicle industry, which will adversely affect the consumption of refined oil products. Competition puts pressure on product prices, affects oil products marketing and requires continuous management focus on identifying new trends, reducing unit costs and improving efficiency. The implementation of our growth strategy requires continued technological advances and innovation, including advances in exploration, production, refining, petrochemicals manufacturing technology and advances in technology related to energy usage. Our performance could be impeded if competitors developed or acquired intellectual property rights to technology that we required or if our innovation lagged the industry.

The Eastern and Southern regions of China have a higher demand for refined products and chemical products than the Western and Northern regions. Although we have strived to increase our refinery capacity in the Southern regions of China over recent years, most of our refineries and chemical plants are located in the Northeastern and Northwestern regions of China. We incur relatively higher transportation costs for delivery of our refined products and chemical products to certain areas of the Eastern and Southern regions from our refineries and chemical plants in Western and Northern China. We face strong competition from other traditional domestic oil companies, local independent refineries and other competitors. As a result, we

expect that we will continue to encounter difficulty in increasing our sales of refined products and chemical products in these regions.

Risks Related to Outbound Investments and Trading

We are subject to various political, legal and regulatory environments in foreign developing countries where we operate, some of which are known to be unstable and differ in certain significant respects from those prevailing in developed countries. The main factors affecting our outbound investments include unstable political situations, unstable tax policies and unstable regulatory regimes. CNPC, our controlling

entities on or after August 25, 2017, with certain exceptions for short-term debt. Neither CNPC nor PetroChina purchased such new debt securities issued by the Government of Venezuela or by PdVSA, nor did they provide any assistance to third parties in this regard. In 2019, the United States issued enhanced sanction measures against Venezuela, which included blocking the property of Venezuelan government and its controlled entities (including PdVSA), and introducing new restrictions on Venezuela’s oil sector. Under these programs, persons determined to be operating in the oil sector of the Venezuelan economy, or to have materially assisted, sponsored, or provided financial, material, or technological support for, or goods or services to or in support of, any person included on the list of SDNs and Blocked Persons, may also be subject to risk of being designated for blocking sanctions. CNPC has longstanding trading and investment activities in Venezuela. In 2018, based on certain pre-existing contract obligations, we purchased

conditions, setting financial and tax policy, foreign exchange policy and monetary policy, regulating financial services and institutions, and providing preferential treatment to certain industries. Some of these measures may benefit the overall Chinese economy, but may also have an adverse effect on us.

Our operations, like those of other PRC oil and gas companies, are subject to extensive regulations and control by the PRC government. These regulations and control affect many material aspects of our operations, such as exploration and production licensing, pricing, industry-specific andproduct-specific taxes and fees and environmental and safety standards. As a result, we may face significant constraints on our ability to implement our business strategies, to develop or expand our business operations or to maximize our profitability. Our business may also be affected by future changes in certain policies of the PRC government with respect to the oil and gas industry.

Currently, the PRC government must approve the construction and major renovation of significant refining and petrochemical facilities as well as the construction of significant crude oil, natural gas and refined product pipelines and storage facilities. We presently have several significant projects pending approval from the relevant government authorities and will need approvals from the relevant government authorities in connection with several other significant projects. We do not have control over the timing and outcome of the final project approvals.

Because PRC laws, regulations and legal requirements dealing with economic matters continue to evolve, and because of the limited volume of published judicial interpretations and thenon-binding nature of prior court decisions, the interpretation and enforcement of these laws, regulations and legal requirements involve some uncertainty. Because theThe PRC Company Law islaws and regulations with respect to companies, securities and litigations are different in certain important aspects from company lawsthose in the United States, Hong Kong and other common law jurisdictions, and becausemost of our assets are located in the PRC and most of our directors and substantially all of our executive officers reside in the PRC. As a result, it may be difficult or impossible for our shareholders (including holders of our ADSs) to bring an action against us or our directors and officers in an event that they believe their rights have been infringed. Even if any shareholders are successful in an action of this kind, they may be unable to enforce a judgment against our assets or the assets of our directors and officers.

Furthermore, due to jurisdictional limitations, the ability of U.S. authorities, such as the U.S. Securities and Exchange Commission, or the SEC, and the U.S. Department of Justice, or the DOJ, to investigate and bring enforcement actions against us may be limited. PRC laws may constrain the ability of our company and our directors and officers to cooperate with such an investigation or action. For example, according to Article 177 of the newly amended PRC Securities Law, which became effective in March 2020, no overseas securities regulator is allowed to directly conduct investigations or evidence collection activities within the territory of the PRC. Without the consent of China Securities Regulatory Commission, or CSRC, and other relevant PRC authorities, no organization or individual may provide documents or materials relating to securities business activities to overseas parties. As a result of the foregoing, you may have more difficulty in protecting your interests through actions against our company, directors, officers or our majority shareholder. Shareholder protection through actions initiated by the SEC, DOJ and other U.S. authorities may also be limited.

Risks Relating Financial Reporting Differences

As a foreign private issuer, we are exempt from certain disclosure requirements under the U.S. Exchange Act, which may afford less protection to you than you would enjoy if we were a domestic U.S. company. As a foreign private issuer, we are exempt from, among other things, the rules prescribing the furnishing and content of proxy statements under the U.S. Exchange Act and the rules relating to selective disclosure of material nonpublic information under Regulation FD under the U.S. Exchange Act. In addition, our executive officers, directors and principal shareholders are exempt from the reporting and short-swing profit and recovery provisions contained in Section 16 of the U.S. Exchange Act. We are also not required under the U.S. Exchange Act to file periodic reports and financial statements with the SEC as frequently or as promptly as domestic U.S. companies with securities registered under the U.S. Exchange Act. For example, in addition to annual reports with audited financial statements, domestic U.S. companies are required to file

lawswith the SEC quarterly reports that include interim financial statements reviewed by an independent registered public accounting firm and regulationscertified by the companies’ principal executive and financial officers. By contrast, as a foreign private issuer, we are still at a stagenot required to file such quarterly reports with the SEC or to provide quarterly certifications by our principal executive and financial officers. Although we are required by the listing rules of development, you mayShanghai Stock Exchange with respect to our A Shares to publish quarterly and semi-annual reports and also required by listing rules of Hong Kong Stock Exchange with respect to our H Shares to publish semi-annual reports, and such reports are furnished to the SEC on Form 6-K, our financial statements included in the reports are not enjoy the shareholders’ protections that you may be entitled to in other jurisdictions.reviewed by our independent registered public accounting firms, and are only reviewed and signed by all our directors, president and CFO.

Risks Related to Controlling Shareholder

As of December 31, 2018,2020, CNPC beneficially owned approximately 81.03%80.41% of our share capital. This ownership percentage enables CNPC to elect our entire board of directors without the concurrence of any of our other shareholders. Accordingly, CNPC is in a position to:

CNPC’s interests may sometimes conflict with those of some or all of our minority shareholders. We cannot assure you that CNPC, as our controlling shareholder, will always vote its shares in a way that benefits our minority shareholders.

In addition to its relationship with us as our controlling shareholder, CNPC by itself or through its affiliates also provides us with certain services and products necessary for our business activities, such as construction and technical services, production services, materials supply services, social services and financial services. The interests of CNPC and its affiliates as providers of these services and products to us may conflict with our interests.

Risks Related to Pricing and Exchange Rate

Our operations are affected by the volatility of prices for crude oil, refined products and natural gas. We set our crude oil median prices monthly based on the international trading prices for crude oil.

In recent years, international prices for crude oil have fluctuated substantially in response to changes in global and regional economy, politics and supply and demand for crude oil. We do not have, and will not have, control over factors affecting international prices for crude oil. Fluctuations and volatility in crude oil prices have a significant impact in our results of operations. A decline in crude oil prices may reduce revenues from, and may result in a loss in, our exploration and production segment. For example, during the first half of 2020, due to the outbreak of COVID-19 pandemic and some other reasons, there was a rarely seen drastic drop in oil prices with an unprecedented negative oil price reported. The decline in international crude oil prices is expected to greatly affect our upstream business profits and oil and gas import costs, and affect our downstream business profits through China’s pricing mechanism of refined oil products, thereby adversely affecting our overall sales revenue and profits. Further, if crude oil prices remain at a low level for a prolonged period, our company haswe would be required to determine and estimate whether our oil and gas assets may suffer impairment and, if so, the amount of the impairment. An increase in crude oil prices may, however, increase the production costs of refined products, reduce demand for our products and affect our operating profits.

Under the current refined oil pricing mechanism implemented by the PRC government, has gradually improved its refined oil pricing mechanism. Whenwhen there is a change in the average crude oil price in the international market during a given time period, the PRC government can adjust refined oil prices. When international crude oil price experiences sustained increases or becomes significantly volatile, the PRC government may increase its control over the refined oil prices. As a result, the regulation on refined product prices by the PRC government may reduce our profit and cause our refining assets to suffer impairment.

We negotiate the actual settlement price with natural gas users within the price range permitted by the PRC government. When the domestic price is lower than the international natural gas price, the cost of our imported natural gas will be higher than the sales price of our natural gas, which may reduce our revenues and profit, or result in losses, cause our natural gas assets to suffer impairment.

Risks Related to COVID-19

During the first half of 2020, affected by the COVID-19 pandemic, the global oil supply and demand were severely imbalanced, resulting in a precipitous fall in oil prices, creating heavy pressure on the oil and gas industry, which in turn posed a tough challenge to our operations. Many countries’ governments have imposed increasingly stringent restrictions to help avoid, or slow down, the spreading of COVID-19, including, for example, restrictions on international and local travel, public gatherings and participation in meetings, as well as closures of universities, schools, stores and restaurants, with some countries imposing strict curfews. In China, various forms of restrictions were imposed and certain of them continue to be in place, and there can be no assurance that these restrictions will not be extended further on one or more occasions. These measures have led to a significant decline in demand for, and prices of, our refined oil products and natural gas, and the restrictions had an adverse effect in the short to medium-term on our oil and gas business chains. Globally, these widespread restrictions in various countries across the world resulted in a decrease in demand for oil, thereby also putting pressure on global oil prices. Although some of the measures, particularly in China, have been lifted, there can be no assurance that these measures will not be reinstated.

Moving forward, the impact of the COVID-19 pandemic on our business will depend on a range of factors which we are not able to accurately predict, including the duration, severity and scope of the pandemic, including any variants or resurgence and efficacy of any vaccines, the geographies impacted, the impact of the pandemic on economic activity in China and globally, and the nature and aggressiveness of measures adopted by governments. These factors include, but are not limited to:

As of the date of this report, there is significant uncertainty relating to the severity of the long-term adverse impact of the COVID-19 pandemic on the global economy, global financial markets and the Chinese economy, and we are unable to accurately predict the long-term impact of the COVID-19 pandemic on our business. To the extent the COVID-19 pandemic will adversely affect our business and financial results, it may also have the effect of heightening many of the other risks described in this ‘‘Risk Factors’’ section, such as those relating to macro-economic conditions, pricing and our liquidity. See also “Risk Factors — Risks Related to Marco Economic Conditions”, “Risk Factors — Risks Related to Pricing and Exchange Rate.” and “Risk Factors — Risks Related to Liquidity”.

Risks Related to Climate Change

In recent years, the oil industry has faced an increasingly severe challenge imposed by global climate change. Numerous international, domestic and regional treaties and agreements that restrict the emission of greenhouse gascarbon emissions have been executed and become effective. China and some other countries in which we operate have adopted, or are considering the adoption of, regulatory frameworksregulations to reduce greenhouse gascarbon emissions. These include adoption of carbon emission quota and trade regimes, carbon taxes, increased efficiency standards, and

incentives or mandates for renewable energies.clean energy. The Chinese government has announced that China aims to hit peak emissions before 2030 and realize carbon neutrality by 2060. These requirementspolicies and measures will bring opportunities to our new energy business, but may lead to a substantialan increase in our expenditures for our conventional oil and gas business, make our oil products more expensive lengthen our project time,

effective, and our independent registered public accounting firm has issued an attestation report, which concluded that our internal control over financial reporting was effective in all material aspects as of December 31, 2018,2020, we may discover other deficiencies in the course of our future evaluation of our internal control over our financial reporting and may be unable to remediate such deficiencies in a timely manner. If we fail to maintain the adequacy of our internal control over financial reporting, we may not be able to conclude that we have effective internal control over financial reporting on an ongoing basis, in accordance with theSarbanes-Oxley Act. Moreover, effective internal control is necessary for us to produce reliable financial reports and is important to prevent fraud. As a result, our failure to maintain effective internal control over financial reporting could result in the loss of investor confidence in the reliability of our financial statements, which in turn could harm our business and negatively impact the trading prices of our ADSs, H Shares or A Shares.shares.

Risks Related to Audit Reports Prepared by an Auditor who is not Inspected by the Public Company Accounting Oversight Board

As a company with shares registered with the U.S. Securities and Exchange Commission, or the SEC, and traded publicly in the United States, our independent registered public accounting firm is required under the laws of the United States to be registered with the Public Company Accounting Oversight Board, or the PCAOB, and undergo regular inspections by the PCAOB to assess its compliance with the laws of the United States and professional standards. TheUnder PRC laws, however, the PCAOB however, is currently unable to inspect a registered public accounting firm’s audit work relating to a company’s operations in China wherewithout the documentationapproval of suchthe Chinese authorities. The CSRC also stated that cross-border audit work is located in China.supervision should be realized through regulatory cooperation between China and the United States. Accordingly, our independent registered public accounting firm’s audit of our operations in China is not subject to PCAOB inspections. In recent years, the SEC and the PCAOB inspection.have issued a number of joint statements highlighting continued challenges faced by the U.S. regulators in their oversight of financial statement audits of U.S.-listed companies with significant operations in China. In December 2020, the Holding Foreign Companies Accountable Act, or the HFCA Act, was signed into law. Among others, the HFCA Act requires (i) the SEC to prohibit securities of an identified foreign company listed in the U.S. from being traded on any national securities exchange or over-the-counter market in the U.S., if for three consecutive years, the company’s auditor that has a branch or office located in a foreign jurisdiction, and the PCAOB is unable to inspect or investigate the auditor completely because of a position taken by an authority in the foreign jurisdiction; (ii) such identified company to satisfy certain disclosure requirements. In March 2021, the SEC issued interim final rules to implement the disclosure requirements of the HFCA Act. We will be required to comply with these disclosure rules if the SEC identifies us as a covered issuer under a process to be subsequently established by the SEC. Rules of SEC to implement the trading prohibition requirement of the HFCA Act has not yet issued. Besides, in August 2020, the United State President’s Working Group on Financial Markets, or the PWG, released the Report and Recommendations on Protecting Investors from Significant Risks from Chinese Companies, or the Report. The PWG recommended that the SEC take steps to implement the recommendations outlined in the report. In particular, to address companies from jurisdictions, such as China, that do not provide the PCAOB with sufficient access to fulfill its statutory mandate, the PWG recommended enhanced listing standards on U.S. exchanges and require, as a condition to initial and continued exchange listing, PCAOB access to work papers of the principal audit firm for the audit of the listed companies. The PWG recommended the new listing standards could provide for a transition period until January 1, 2022 for currently listed companies. Implementation of the HFCA Act, the Report or other efforts to increase U.S. regulatory access to audit information could result in a suspension of trading or even mandatory delisting of our ADSs from the NYSE. This would subject our investors and us to uncertainty and have an adverse effect on the market price of our ADSs.

The PCAOB has conducted inspections of independent registered public accounting firms outside of China and has at times identified deficiencies in the audit procedures and quality control procedures of those accounting firms. Such deficiencies may be addressed in those accounting firms’ future inspection process

to improve their audit quality. Due to the lack of PCAOB regular inspections of audit work undertaken in China, our investors do not have the benefit of the PCAOB inspection of our independent registered public accounting firm’s audit work and audit quality control procedures.

Risks Related to SEC Litigation Against the “Big Four”PRC-based Accounting Firms

On January 22, 2014, Judge Cameron Elliot, an SEC administrative law judge, issued an initial decision suspending the Chinese member firms of the “Big Four” accounting firms, including our independent registered public accounting firm, from, among other things, practicing before the SEC for six months. In February 2014, the initial decision was appealed. While under appeal and in February 2015, the Chinese member firms of “Big Four” accounting firms reached a settlement with the SEC. As part of the settlement, each of the Chinese member firms of “Big Four” accounting firms agreed to settlement terms that include a censure, undertakings to make a payment to the SEC, procedures and undertakings as to future requests for documents by the SEC and possible additional proceedings and remedies should those undertakings not be adhered to.

IfHad the settlement terms are not been adhered to, the Chinese member firms of “Big Four” accounting firms may becould have been suspended from practicing before the SEC, which could in turn delay the timely filing of our financial statements with the SEC. In addition, it could be difficult for us to timely identify and engage another registered public accounting firm to audit and issue an opinion on our financial statements and our internal control over financial reporting. A delinquency in our filing of the annual report with the SEC may result in the NYSE initiating delisting procedures, which could harm our reputation and have other material adverse effects on our overall growth and prospect.

fail to prevent employee misconduct, our reputation may be harmed, and the trading price of our ordinary shares and ADSs could be adversely affected.

Risks Related to Cyber Security

Our activities depend heavily on the reliability and security of our information technology (“IT”) systems. Our IT systems may suffer disruptions due to cyber-attack, computer intrusions and viruses, technical failure and disruptions, power and network outages or natural disasters. We have adopted multi-layer technological measures for prevention and detection of cybersecurity problems, and we also train our employees in order to improve their awareness and ability to detect and respond to cybersecurity situations. If our measures prove to be insufficient, the cybersecurity disruptions could damage or destroy assets, compromise business systems, result in proprietary information being altered, lost, or stolen; result in employee, customer, or third-party information or material intellectual property being compromised, cause physical harm to people or the environment, or otherwise disrupt our business operations. We could incur significant costs to remedy the effects of a major cybersecurity disruption in addition to costs in connection with resulting regulatory actions, litigation or reputational harm. As a result, we and our customers, employees, or third parties could be adversely affected, potentially having a material adverse effect on our business and financial conditions.

Item 4— INFORMATION ON THE COMPANY

Introduction

History and Development of Our Company

Our legal name is “ 中国石油天然气股份有限公司” and its English translation is PetroChina Company Limited.

We are the largest oil and gas producer and seller occupying a leading position in the oil and gas industry in the PRC and one of the largest companies in the world. We are engaged in a broad range of petroleum and natural gas related activities, mainly including the exploration, development, production and marketing of crude oil and natural gas; the refining of crude oil and petroleum products, as well as the production and marketing of basic petrochemical products, derivative chemical products and other chemical products; the marketing of refined oil products and trading; and the transmission of natural gas, crude oil and refined oil products as well as the sale of natural gas.

Currently, substantially all of our crude oil and natural gas reserves andproduction-related assets are located in China. Our exploration, development and production activities commenced in the early 1950s. Over more than sixFor seven decades, we have conducted crude oil and natural gas exploration activities in many regions of China.

We commenced limited refining activities in themid-1950s. Our chemicals operations commenced in the early 1950s. In the early 1960s, we began producing ethylene. Our natural gas transmission and marketing activities commenced in Sichuan in Southwestern China in the 1950s.

We were established as a joint stock company with limited liability under the Company Law of the PRC on November 5, 1999 as part of a restructuring in which CNPC transferred to us most of the assets and liabilities of CNPC relating to its exploration and production, refining and marketing, chemicals and natural gas businesses.

On April 7, 2000, we completed a global offering of H Shares and ADSs. In September 2005, we completed afollow-on offering of over 3 billion H Shares at the price of HK$6.00 per share.Shares. In October 2007, we issued 4 billion A Shares at an issue price of RMB16.7 per share.Shares. The A Shares were listed on the Shanghai Stock Exchange on November 5, 2007. As of December 31, 2018,2020, CNPC beneficially owned 148,010,665,536146,882,339,136 A Shares and 291,518,000 H Shares in us, representing approximately 81.03%80.41% of our share capital in aggregate. The H Shares held by CNPC were through Fairy King Investments Limited, an overseas wholly owned subsidiary of CNPC.

For a description of our principal subsidiaries, see Note 1918 to our consolidated financial statements.

Our headquarters are located at 9 Dongzhimen North Street, Dongcheng District, Beijing, China, 100007, and our telephone number at this address is (86-10) 5998-2622. Our website address iswww.petrochina.com.cn. The information on our website is not part of this annual report. Our annual report on form20-F and other reports filed electronically with the SEC can be found on the SEC’s websitewww.sec.gov.

Our Corporate Organization Structure

The following chart illustrates our corporate organization structure as of December 31, 2018.2020.

Acquisition Agreements on PetroChina Pipeline Co., Ltd., and others) and (iii) the Production and Operation Agreement. Pursuant to these agreements, we agreed to sell, and PipeChina agreed to buy, our interests in certain of our subsidiaries, branches, associated companies (“target entities”), which together held our major oil and gas pipelines, certain gas storage facilities, oil storage facilities, LNG terminals and ancillary facilities, and the initial oil and gas inventory contained therein (together, the “target assets”) in exchange for 29.9% of the equity interests in PipeChina and a cash consideration (the “transaction”). The consideration for the transaction was based on the appraised value of the target assets as of December 31, 2019. The final consideration shall be determined based on an audit taking into account such factors as the profit and loss of the target assets during the transitional period, the adjustments for subsequent events after the base date and the value of the initial oil and gas inventory at the time of delivery. PipeChina warranted that after completion of the transactions, the target assets shall remain in normal operations, and the quality of the services provided to us to be no lower than the previous level. Furthermore, PipeChina undertook that it will not take any action or allow any nonaction that may adversely affect our continuous normal use of any target assets in our production or operation.

On September 28, 2020, the transaction was approved at the general meeting of our company by 99.9963% of votes. On September 30, 2020, all the conditions precedent to the closing of the transaction were satisfied, and the ownership, obligations, responsibilities and risk of the target assets were passed from our company to PipeChina at 24:00 on September 30, 2020.

The total assets sold in the transaction amounted to RMB356,447 million and the book value of net assets attributable to the owners of the Company was RMB200,525 million. The total final consideration was RMB247,471 million, including (i) RMB149,500 million that we recognized as long-term equity investment in PipeChina corresponding to the 29.9% equity interests in PipeChina, and (ii) a cash consideration of RMB97,971 million. For this transaction, we recognized pre-tax profit of RMB46,946 million. The difference between the final adjusted amounts and the amounts that we initially annouced reflected the adjustment mainly due to (i) the changes in prices and quantity of the initial oil and gas inventory and (ii) distribution of profits by certain of the target entities in advance of closing of the transaction.

On December 22, 2020, Kunlun Energy Company Limited (“Kunlun Energy”), a subsidiary of our company, entered into an Equity Transfer Agreement with PipeChina, pursuant to which we were granted 10%Kunlun Energy agreed to sell and PipeChina agreed to purchase 60% equity interestinterests in the Abu Dhabi Umm Shaif & Nasr Oilfield for a fee of US$575 millionPetroChina Beijing Gas Pipeline Co., Ltd. (“Beijing Pipeline”) and 10%75% equity interestinterests in the Lower Zakum Oilfield for a fee of US$600 million, both for a term of 40 years.

On September 27, 2018, we entered into an equity purchase agreement with Total S.A. to acquire the 22.407% equity interest held by Total S.A. inPetroChina Dalian West Pacific PetrochemicalLNG Co., Ltd. (“Dalian West Pacific”LNG”). On December 6, 2018, we entered into an equity purchase agreement with each held by Kunlun Energy at a base consideration of Sinochem Group Co.approximately RMB40,886 million (subject to the adjustments according to the price adjustment mechanism as set out in the agreement), Ltd. and Sinochem International Oil (Hong Kong) Co. Ltd.,which shall all be settled in cash by PipeChina. This transaction was completed at 24:00 on March 31, 2021, upon which, Kunlun Energy ceased to acquire 8.424% and 25.208%hold any equity interests in Beijing Pipeline and Dalian West Pacific, respectively. AfterLNG.

We believe that the completionpipeline restructuring transaction will help us focus more on our upstream exploration and development business as well as our downstream distribution business, and can relieve our pressure on capital expenditures, and help us get greater access to the nationwide oil and gas storage and transmission facilities, so to improve our operational efficiency and value creation capabilities.

See also “Item 3 — Key Information — Risks Related to Pipeline Asset Restructuring”. For details, please refer to the English translation of the aforementioned equity purchase, together with our existing equity interest, we will hold a total equity interest of 84.475% equity in Dalian West Pacific and Dalian West Pacific will become one of our principal subsidiaries.transaction agreements included as exhibits to this annual report on Form 20-F.

For information on capital expenditures, please see “Item 5 — Operating and Financial Review and Prospects — Liquidity and Capital Resources — Capital Expenditures and Investments.”

Exploration and Production

We engage in crude oil and natural gas exploration, development and production. Substantially all of our total estimated proved crude oil and natural gas reserves are located in China, principally in Northeastern, Northern, Southwestern and Northwestern China. Meanwhile, we have enhanced our overseas cooperation and expanded our strategic presence in five major overseas oil and gas cooperation regions by conducting new project development. In 2018,2020, the crude oil and natural gas produced by us at overseas regions accounted for 17.6%19.3%% and 7.8%5.4% of our total production of crude oil and natural gas, respectively.

We currently hold exploration and exploitation licenses for oil and gas (including coal seam gas) covering a total area of approximately 295.5272.4 million acres, including the exploration licenses covering a total area of approximately 264.8240.3 million acres and the exploitationproduction licenses covering a total area of approximately 30.732.1 million acres.

The following table sets forth the financial and operating data of our exploration and production segment for each of the years ended December 31, 2016, 20172018, 2019 and 2018:2020:

Reserves

As of December 31, 2018,2020, our total estimated proved reserves of crude oil was approximately 7,640.85,206.1 million barrels and our total estimated proved reserves of natural gas was approximately 76,467.076,437.1 Bcf. As of December 31, 2018,2020, proved developed reserves for crude oil and natural gas accounted for 76.5%89.4% and 52.5%55.0% of our total proved crude oil and natural gashydrocarbon reserves, respectively. Total proved hydrocarbon reserves, including our overseas crude oil reserves of 811.0831.1 million barrels and overseas natural gas reserves of 1,986.91,642.90 Bcf, increaseddecreased by 0.44%10.1% from approximately 20,295.919,959.3 million BOE as of December 31, 20172019 to approximately 20,385.317,945.6 million BOE as of December 31, 2018.2020, primarily due to the decrease in oil and natural gas prices. Natural gas as a percentage of total proved hydrocarbon reserves decreasedincreased from 63.1%63.7% as of December 31, 20172019 to 62.5%71.0% as of December 31, 2018.2020.

Approximately 33%, 54% and 54% of our estimated proved reserves as of December 31, 2018, was2019 and 2020, respectively, were assessed by our internal assessment team and audited by our independent engineering consultant. The other part ofconsultants. Other information regarding our estimated proved reserves as of December 31, 2018 and the estimated proved reserves as of December 31, 2016 and 2017 werewas based on the assessment performedreserves reports prepared by our independent engineering consultants according to the reserves assessment methodology generally adopted in the U.S. Our independent engineering consultants for 2016, 2017 and 2018 were DeGolyer and MacNaughton, Ryder Scott Company L.P., GLJ Petroleum Consultants and McDaniel & Associates Consultants Ltd. in accordance with the reserves assessment methodology generally adopted in the U.S. The reserves assessments and reports of our company were performed and prepared in compliance with SEC’s oil and gas reserves reporting rules. Our reserves estimates include only crude oil and natural gas which we believe can be reasonably produced within the current terms of our production licenses or within the terms of the licenses which we are reasonably certain canto be renewed. See “Regulatory Matters — Exploration Licenses and Production Licenses” for a discussion of our production licenses. Also see “Item 3 — Key Information — Risk Factors — Risks Related to Oil and Gas Reserves” for a discussion of the uncertainty inherent in the estimation of proved reserves.

Our reserves data in 2016, 2017 and 2018 were prepared in accordance with the SEC’s final rules on “Modernization of Oil and Gas Reporting”.

Internal Controls Over Reserves Estimates

We have appointed a Reserves Assessment Directing Team,reserves assessment directing team, or the RAD Team. The leader of the RAD Team is our president.vice president in charge of our upstream business.

We have implemented a practicing professional certification regime to supervise our employees engaged in oil and gas reserves evaluation and auditing functions. We have set up a team of reserves auditors covering our headquarter office and regional companies to perform reserves evaluation and audits. Meanwhile, we have established a special reserves management department in our exploration and production segment. Each of the officers and employees of that department has over 20 years’years of experience in oil industry and over 10 years’many years of experience inSEC-guided reserves evaluation. All of the members of that department have been recoginized as national-level registered qualifications in reserves expertise.experts. Each regional company has established a reserves management committee and amulti-disciplinary reserves research office. Mr. Duan Xiaowen from the Reserves Administration Division of theour exploration and production segment,branch company, is the person in charge of our reserves estimation. Mr. Duan holds a bachelor’s degree in geology and a master’s degree in business administration. He has over 25many years of work experience in oil and gas exploration and development industry and has been engaged in reserves estimate and management for a long time. Since 2008, Mr. Duan has been involved in the supervision of reserves estimation and management in our company. In 2016, Mr. Duan became the division head primarily responsible for overseeing the preparation of the reserves estimates, estimation technology and management. The reserves research offices of the regional companies are responsible for estimating newly discovered reserves and updating the estimates of existing reserves. The results of our oil and gas reserves assessment are subject to atwo-level review by both the regional companies and our exploration and production branch company, with final examination and approval byof the RAD Team.

In addition, we commissioned independent assessment firms to independently reassess or audit our annually assessed proved reserves in accordance with relevant SEC rules. We disclose the reserves in accordance with the SEC requirements.

Third-Party Reserves Reports

DeGolyer and MacNaughton, an independent petroleum engineering consulting firm based in the United States, carried out an independent assessment and audit of our reserves in China and certain other countries as of December 31, 2016, 20172018, 2019 and 2018.2020. Mr. Thomas C. Pence, a senior vice president of DeGolyer and MacNaughton, is primarilywas responsible for supervising the preparation of our reserves report. Mr. Pence is a Registered Professional Engineer in Texas, a member of the International Society of Petroleum Engineers, and has over 36many years of experience in oil and gas reservoir studies and reserves evaluations.

Ryder Scott Company, L.P. (“Ryder Scott”), an independent petroleum engineering consulting firm based in the United States, carried out an independent assessment of certain of our selected petroleum assets such as in Chad, West QurnaIraq and Peru as of December 31, 2016, 20172018, 2019 and 2018.2020. Mr. Timour Baichev, a vice president of Ryder Scott, was responsible for overseeing the estimate of the reserves, future production and income as stated in the reserves report. Mr. Timour Baichev is a licensed professional engineer and has over 35many years of experience in the petroleum reserves estimation and evaluation.

GLJ Petroleum Consultants (“GLJ”), a petroleum consulting firm based in Canada, carried out an independent assessment of our reserves for certain gas and oil properties in Canada as of December 31, 2016, 20172018, 2019 and 2018.2020. Ms. Trisha S. MacDonald was the project manager for the evaluation. She is a senior engineer and has over 10many years of relevant experience.experience in oil and gas reservoir studies and reserves evaluations.

of our reserves report. Mr. Boulton is a member of the Association of Professional Engineers and Geoscientists of Alberta and a member of Society of Petroleum Engineers.Alberta. He has over 10 years’many years of experience in oil and gas reservoir evaluation.studies and reserves evaluations.

None of the above consulting firms or their partners, senior officers or employees has any direct or indirect financial interest in our company and the remunerations to the firms are not in any way contingent upon reported reserves estimates.

For detailed information about our net proved reserves estimates, please refer to the summary reports of reserves filed herewith as exhibits to this annual report on Form20-F.

The following table sets forth our estimated proved reserves (including proved developed reserves and proved undeveloped reserves), proved developed reserves and proved undeveloped reserves of crude oil and natural gas as of December 31, 2016, 20172018, 2019 and 2018.2020.

As of December 31, 2018, 2019 and 2020, our total proved developed and undeveloped reserves on consolidated basis and on equity method, were 20,778 million BOE, 20,312 million BOE, and 18,202 million BOE, including 7,962 million, 7,540 million and 5,402 million barrels of crude oil and condense, and 76,896.4 Bcf, 76,629.6 Bcf and 76,799.8 Bcf of natural gas.

Our proved undeveloped reserves were 7,854.26,279.2 million BOE as of December 31, 2018.2020, representing a decrease of 19.9% as compared to 2019. The main changes in our proved undeveloped reserves in 20182020 included (i) an increase of 1,188.31,214.6 million BOE through extensions and discoveries; (ii) an increase of 95.9107.7 million BOE through improved recovery; (iii) a decrease of 223.91,263.2 million BOE primarily due to our optimization adjustmentthe decrease in the investment plans with respect to certain existing proved undeveloped reserves considering certain new discoveries; andoil prices; (iv) the conversion of 1,368.81,631.1 million BOE of proved undeveloped reserves into proved developed reserves; and (v) purchase of 10.6 million BOE of proved undeveloped reserves. In 2018,2020, we spent RMB134,995RMB127,576 million on developing proved undeveloped reserves. The overwhelming majority of our proved undeveloped reserves were situated around the oil fields that are currently producing. The majority of our proved undeveloped reserves are already scheduled for development within five years after initial booking.

Some of our natural gas proved undeveloped reserves of natural gas are being developed more than five years after their initial disclosure primarily due to the effect oflong-term natural gas supply contracts. The sale of natural gas produced from our reserves located in China is subject to ourlong-term contractual obligations to provide a stable supply of natural gas to customers. We sell all of the natural gas through our pipelines and underlong-term supply arrangements with customers.

There are mainly two types oflong-term supply arrangements. The first ismulti-year supply contracts with terms ranging from 20 to 30 years that can be extended upon mutual agreement. The second type is renewable annual contracts. The majority of the natural gas produced fromin our gas fields in China is put into ourthe nationwide,long-range pipeline system andto be sold to customers who have entered intomulti-year supply contracts with us in the areas where thelong-range pipeline system covers. A small portion of the natural gas produced by our company is put into local or internal pipeline systems andto be sold to customers in the areas adjacent to our gas fields. These customers typically have formedde-factolong-termde-facto long-term relationships with our company over the years and enter into supply contracts with us before the year end to determine the amount of gas to be purchased for the next year, with such contracts being renewed every year. In general, our supply relationships with customers under the annual contracts have existed for more than ten years.

Mainly as a result of our contractual obligations to ensure along-term, stable supply of natural gas to customers, we must maintain a relatively large amount of proved undeveloped natural gas reserves and develop them over an extended period of time (in some cases, longer than five years).

The following tables set forth our crude oil and natural gas proved reserves and proved developed reserves by region as of December 31, 2016, 20172018, 2019 and 2018.2020.