Bozhong 26-6, The World's Largest Metamorphic Oil Field, Officially Starts Drilling

On April 24, CNOOC announced that the first phase of the Bozhong 26-6 condensate oil field development project in the Bohai Oilfield has officially started drilling, kicking off the development of the world's largest metamorphic oil field.
The Bozhong 26-6 condensate oil field is located in the southern waters of the Bohai Sea, about 170 kilometers away from Tianjin City, with an average water depth of over 22 meters. In 2024, the newly added proven geological reserves of oil and gas will exceed 40 million cubic meters, pushing the cumulative proven geological reserves of the oil field to exceed 200 million cubic meters, making it the world's largest metamorphic oil field.

It is estimated that the Bozhong 26-6 Oilfield can extract more than 30 million cubic meters of crude oil. After being refined into gasoline, it can meet the daily transportation needs of urban residents with a population of one million for more than 20 years. At the same time, it can extract more than 11 billion cubic meters of natural gas, which can meet the needs of hundreds of millions of people. Urban residents with a population of 10,000 have been using domestic gas for more than 60 years, which has considerable social and economic benefits.
Liu Baosheng, general manager of the Engineering Technology Operation Center of CNOOC Tianjin Branch, said that the average well depth of the Bozhong 26-6 oil field development project is 4,835 meters, with a maximum well depth of 5,049 meters. The drilling footage is expected to exceed 160,000 meters, which is equivalent to drilling through 18 The height of Mount Everest. The target layer is the Archaean buried hill metamorphic rock formation, which is a bedrock bulge covered by new sedimentary rocks during the ancient geological history billions of years ago. That is, the ancient mountain tops are covered and sink to the ground as time goes by. Thousands of meters deep, it belongs to the ancient landform of bedrock. This project has once again laid a solid foundation for my country's offshore oil industry exploration and development to move into deep and complex fields.

The bedrock of the buried hill is mainly high-hardness granite, with an average compressive strength of 137-275 MPa, which is nearly 9 times higher than that of concrete and even higher than the strength of cast iron. Due to its deep burial, the formation temperature reaches 178°C. This high-temperature and high-intensity extreme operating environment brings severe challenges to the reliability of drilling instruments and equipment. In order to ensure the efficient development of oil fields, CNOOC has promoted the improvement of drill bits, high-temperature mud systems, supporting speed-increasing tools and high-temperature directional well instruments. It has completed targeted improvements to drilling rig equipment, especially the upgrade and optimization of high-torque resistance drilling tools. It has reached the domestic leading level and ensured the smooth development and production of oil fields.
Yu Guimin, deputy general manager of CNOOC Tianjin Branch, said, "Bozhong 26-6 is the world's largest buried hill metamorphic oil field. Its successful exploration and development has increased the confidence and confidence for the Bohai Oilfield to increase its annual oil and gas production to 40 million tons. Improve my country's research on key core technologies for deep offshore drilling and completion, and continue to make progress towards the development of deep ocean energy."