After Bozhong 19-6, Kenli 6-1 and other large oil and gas fields, another 100 million ton oil and gas discovery has been made in the Bohai Sea area of China.

On February 22, 2021, interface news learned from China National Offshore Oil Corporation (CNOOC) that the newly discovered Bozhong 13-2 oil and gas field of CNOOC has proven geological reserves of 100 million tons of oil and gas equivalent.

CNOOC said that Bozhong 13-2 oil and gas field is located in the Central Bohai Sea, about 140 km away from Tianjin, with an average water depth of 23.2 meters. It is found that a total of 346m thick oil layer was drilled in well Bozhong 13-2-2, with a drilling depth of 5223m. After testing, the average daily output of crude oil is about 300 tons and natural gas is about 150000 cubic meters.

CNOOC said that after the Bozhong 13-2 oil and gas field is put into operation, it will cooperate with Bozhong 19-6 condensate field and other oil and gas fields in production, laying a foundation for Bohai oilfield to become the largest crude oil production base in China.

Last year, Bohai oilfield produced 30.7 million tons of oil and gas equivalent, ranking fourth among China's top ten oil and gas fields. Among them, crude oil output is 28.3 million tons.

At present, China's largest crude oil production base is Daqing Oilfield, which produced more than 30 million tons of crude oil last year.

The largest oil and gas field in China is Changqing Oilfield. As of December last year, the annual oil and gas equivalent of Changqing Oilfield exceeded 60 million tons, reaching 60.008 million tons. Among them, crude oil production reached 24.518 million tons and natural gas production reached 44.531 billion cubic meters.

Zhou Xinhuai, general manager of CNOOC exploration department, said that the discovery of Bozhong 13-2 oil and gas field has achieved a major breakthrough in the exploration of "covered" buried hills in the Bohai Sea, greatly expanded the exploration space of buried hills, and has important promotional value for the future exploration of similar buried hills in the Bohai Sea and offshore China.

Half a century ago, CNOOC began to carry out oil and gas exploration in the field of buried hill geological structure in the depth of Bohai Sea, and successively discovered large and medium-sized high buried hill oilfields such as Jinzhou 25-1 south.

In early 2019, with the discovery of Bozhong 19-6 gas condensate field, a new situation of natural gas exploration in buried hill of oil-rich basin in Bohai Bay has been opened. Subsequently, CNOOC explorers further expanded in this area, and evaluated Bozhong 13-2, an extended border block in the northwest of the area.

Zhou Xinhuai said that because the main area discovered in Bozhong 13-2 belongs to Archean buried hill structure, which is covered by Mesozoic tight strata, it is difficult to clearly understand the reservoir, the path of oil and gas migration is unknown, and exploration is difficult. Therefore, CNOOC has not made a large-scale exploration breakthrough in this field.

In recent years, through the innovation of geological knowledge, the exploration personnel of CNOOC put forward a new understanding of reservoir forming mode, breaking the traditional understanding that it is difficult to form high-quality reservoir and large-scale reservoir in covered buried hill, and finally obtained the discovery of Bozhong 13-2 oil and gas field.

In order to realize the efficient conversion of reserves, CNOOC applies the integrated management mode of exploration and development, uses the existing oilfield facilities to promote the production of the well area, and directly converts Bozhong 13-2 exploration well into production well for production test. This not only reduces the drilling cost, but also increases the oil and gas production.

Zhou Xinhuai introduced that during the "fourteenth five year plan" period, Bozhong 13-2 oil and gas field will continue to promote the deployment and implementation of the overall development plan, and become an important force for Bohai oilfield to produce 40 million tons.

In the past two years, CNOOC has made two large-scale oil and gas discoveries in the Bohai Sea.

In 2019, CNOOC announced the discovery of Bozhong 19-6 gas condensate field, with 180 million cubic meters of proven oil reserves and 171.2 billion cubic meters of proven natural gas reserves. On October 22 last year, Bozhong 19-6 gas condensate field test area was put into production safely.

Bozhong 19-6 is the first large-scale, integrated, high-yield and ultra-high condensate gas field in eastern China. Its discovery rewrites the history that there is no atmospheric field in the Bohai Bay Basin, and leads the Bohai Bay super basin from the era of large-scale oil exploration to a new stage of large-scale oil and gas exploration.

In March last year, CNOOC made a large-scale Kenli 6-1 discovery in the northern Laizhou Bay of Bohai Sea, with proved geological reserves of more than 100 million tons, becoming the first large-scale oilfield of 100 million tons in the northern Laizhou Bay of Bohai Sea in China.

As the largest offshore oil and gas producer in China, CNOOC's domestic crude oil production increment ranked first among the three largest oil companies for two consecutive years.

In 2020, CNOOC's total domestic oil and gas production will exceed 65 million tons of oil equivalent, setting a new historical record. Among them, crude oil production increased by 2.403 million tons year-on-year, accounting for more than 80% of the total oil and gas increment of the three major domestic oil companies last year, and natural gas production increased by 2.61 billion cubic meters year-on-year. Video column Director / Liu Lu