A Huge Oil Field was Discovered in the South China Sea

A Huge Oil Field was Discovered in the South China Sea

On March 8, China National Offshore Oil Corporation (CNOOC) announced the discovery of China's first deep-water and deep oil field in the Pearl River Mouth Basin of the South China Sea - Kaiping South Oil Field, with proven oil and gas geological reserves of 102 million tons of oil equivalent.

This oilfield is the largest commercial discovery of nuclear complex depression in the world, showing the broad prospect of deep-water exploration in the South China Sea, further consolidating the reserve base of offshore oil and gas resources in China, and is of great significance for ensuring national energy security.

01, the discovery of large oil fields

Kaiping South Oilfield is located in the Kaiping Depression in the eastern part of the South China Sea, about 300 kilometers away from Shenzhen, with an average water depth of more than 500 meters and the largest well depth of 4,831 meters. The oil is light crude oil. The discovery well drilled 100.6 meters into the oil and gas reservoir, and the average daily production of oil and gas was more than 1,000 tons of oil equivalent, setting a new record for deep water oil and gas test production in China.

The geological conditions of Kaiping depression are complicated and the faults crisscrossed, so the exploration is very difficult. "On the basis of new seismic data, we have deepened the understanding of source rock distribution and hydrocarbon accumulation law, identified oil and gas rich areas, and re-evaluated the amount of resources. Since 2023, we have intensively deployed exploration Wells in the south area of Kaiping, of which 4 exploration Wells have been tested and obtained high industrial oil flow, which confirmed the hydrocarbon source potential of the Kaiping depression, and successfully discovered the South Kaiping oil field of 100 million tons." Cnooc Shenzhen branch general geologist Liu Jun said.

02, deep water drilling problems

The geological conditions of China's offshore basins are far more complicated than those of the Midwestern onshore oil fields with the same burial depth, and covered with a layer of seawater, oil and gas drilling is difficult. When drilling reaches a certain depth limit, the penetrating strata increase, the temperature and pressure conditions become harsh, the formation lithology becomes more complex, and the difficulty increases geometrically.

Because of the cold water in the deep sea, it is difficult to lift oil from the well to the surface, like a truck traveling on a muddy road, each meter of progress takes time and effort.

In order to solve this global problem, the exploration and operation team of CNOOC independently developed the "killer whale" heat lift efficient liquid drainage technology suitable for deep oil and gas fields, breaking through the technical bottleneck of deep water and high condensate oil drainage, turning trucks into "racing cars", muddy roads into highways, and successfully awakening this part of the sleeping "black gold under the sea". It provides a solid technical support for the reserve evaluation and development of south Kaiping oilfield.

"In 2023, we drilled 12 Wells in Kaiping depression, with an average well depth of more than 4,000 meters. Through the application of offshore drilling speed and efficiency improvement technology system, we promoted more than 20 equipment upgrading, which advanced the overall construction period by more than 40 days, broke the record of China's offshore drilling cycle with 2 Wells, and further developed China's offshore deep water drilling and completion technology." Cnooc Shenzhen branch deepwater engineering technology center general manager Zhang Weiguo said.

03, to the deep water

Compared with the traditional exploration areas of shallow water and middle and shallow layers, the exploration degree of deep water and deep water in China is very low, and it is an important substitute area for the growth of oil and gas reserves and production in the future.

According to data released by the National Energy Administration, domestic crude oil production in 2023 reached 208 million tons, of which Marine crude oil production exceeded 62 million tons, an increase of more than 3.4 million tons year-on-year, accounting for about 70% of the country's crude oil increment, supporting the construction capacity of a maritime power to further enhance.

In recent years, China has vigorously strengthened scientific research, innovated geological understanding, and promoted continuous breakthroughs in the theory and engineering technology of offshore deep oil and gas geology, and gradually achieved large-scale oil and gas discoveries such as Bozhong 260-600 million ton deep oil field and Baodao 21-1 deep water gas field.

The discovery of Nan-100 million ton oil field in Kaiping has further revealed the huge exploration potential of deep water area in China.

Zhou Xinhuai, CEO and President of CNOOC, said, "In recent years, CNOOC's oil and gas exploration discoveries in the eastern waters of the South China Sea have repeatedly reached new highs, creating a new growth pole for the continuous increase of offshore oil and gas production. The company will continue to increase its oil and gas exploration and development efforts in the South China Sea and continuously improve its energy supply capacity."