From 1955 to 1969, approximately 4 oil fields were found in 4 areas in Qinghai, Heilongjiang (Daqing oilfield), Bohai Bay and Songliao basin.

The CNPC subsidiary SAPET signed a service contract with the government of Peru to operate Block VII in the Talara Province basin.

[11] In August 2005 it was announced that CNPC agreed to buy the Alberta-based PetroKazakhstan for US$4.18 billion, then the largest overseas acquisition by a Chinese company.

[15] Driven by China's increasing energy needs and supported by the government's Go Out policy, CNPC was among the state-owned enterprises which expanded internationally.

[16]: 77 In 2012, a CNPC subsidiary, the Bank of Kunlun, was sanctioned by the United States because of its financial relationship with the Islamic Revolutionary Guard Corps and the Quds Force.

[17] In July 2013, CNPC and Eni signed a $4.2 billion deal to acquire a 20% stake in a Mozambique offshore natural gas block.

[22] CNPC has 30 international exploration and production projects with operations in Azerbaijan, Canada, Iran, Indonesia, Myanmar, Oman, Peru, Sudan, Niger, Thailand, Turkmenistan, and Venezuela.

[23] In 2018 the company announced it is building natural gas storage facilities with a total capacity of 55.6 billion cu m in the northern Henan province, to ease supply bottlenecks in the peak winter season.

The country has started an ambitious program to convert large numbers of coal-fired boilers to cleaner natural gas, to curb smog and pollution.

[27] The December 2013 beginning of the South Sudanese Civil War prompted Chinese policymakers to consider whether to relinquish oil fields and other investments or to continue to maintain them during the conflict.

[24]: 165 In December 2011, Afghanistan signed a deal with CNPC for the development of oil blocks in the Amu Darya basin, a project expected to earn billions of dollars over two decades; the deal covers drilling and a refinery in the northern provinces of Sar-e Pol and Faryab and is the first international oil production agreement entered into by the Afghan government for several decades.

Political resistance in Kazakhstan to the deal was placated by the sale of a minority stake in PetroKazakhstan by CNPC to KazMunaiGaz, the Kazakh state-owned oil company.

[33] Both CNPC and Sinopec also have an equity stake in the Qatar North Field eastern expansion which amounts to about 5% of an LNG train of 8 million metric tons of year.

The agreement was signed at a summit in Shanghai and is expected to deliver some 38 billion cubic meters of natural gas a year, starting around 2018, to China's burgeoning economy.

The project was accused of involvement in corruption and was suspended by the Pakatan Harapan seventh cabinet of Malaysian Prime Minister Mahathir Mohamed in 2018.

[40]: 93 In March 2009, CNPC began development of Ahdab, an oil field in Wasit Governorate holding a modest one billion barrels, becoming "the first significant foreign investors" in Iraq.

[43][44] A contract was also awarded to a consortium led by CNPC (37.5%), including TotalEnergies (18.75%) and Petronas (18.75%) for the "Halfaya field" in the south of Iraq, which contains an estimated 4.1 billion barrels (650,000,000 m3) of oil.

[52] It held this 80.1% share until it withdrew its investment in October 2019 due to the US sanctions on Iran, according to Oil Minister Bijan Zangeneh quoted by the SHANA news agency.

[54] CNPC also has an equity stake in the Qatar North Field eastern expansion which amounts to about 5% of an LNG train of 8 million metric tons of year.

[55] In September 2013, Jiang Jiemin, a former chairman of PetroChina, a subsidiary of CNPC, was abruptly removed from his role as director of the State-owned Assets Supervision and Administration Commission of the State Council and investigated for corruption and abuse of power, along with four other senior oil executives.

On October 12, 2015, the court found Jiang guilty on all counts, including accepting bribes, possessing dark assets, and abusing his power.

[57] In January 2017, former PetroChina vice chairman Liao Yongyuan was sentenced to 15 years in prison for abuse of power and accepting nearly $2 million worth of bribes.

[58][59] In October 2021, the Central Commission for Discipline Inspection announced that it was investigating former PetroChina vice president Ling Xiao, for "serious disciplinary violations.

[62][63] Specialists concluded that the accident was the result of negligence on the part of Eastern Sichuan Drilling Company, which was working under China National Petroleum Corporation.

[63] They concluded that Sichuan technicians had failed to fix a blowout-prevention valve, a basic safety measure, that the gas well was built too close to homes, that workers failed to promptly inform authorities, that workers neglected to ignite the gas to prevent disaster, and that the company had not undergone an official environmental and safety assessment before commencing operations.

[65] "We found flagrant violations of environmental standards by the company ... CNPC's behavior was unacceptable," said Le Bemadjiel, Chad's minister of oil.

[68] In November 2005, chemical plants belonging to PetroChina, a subsidiary of CNPC, exploded in Jilin, China, resulting in 100 tons of benzene, which is a carcinogen and toxic, pouring into the Songhua River.

In July 2010, two pipelines exploded at an oil storage depot belonging to China National Petroleum Corp near Dalian's Xingang Harbour in Liaoning province which spilled an estimated 1,500 tonnes of crude into the sea.

[77] In 2011, Earthrights International accused PetroChina, a subsidiary of CNPC, of complicity in serious human rights abuses in Burma,[78][79] a country known for militarily furthering its economic interests through the use of forced labor.

[80][81] In January 2014, the International Consortium of Investigative Journalists published research based on leaked financial records from the British Virgin Islands, implicating CNPC, PetroChina, Sinopec, and CNOOC in offshore tax evasion.