Going to the five oceans to explore energy! What major breakthroughs have been made in China's deep-sea oil and gas development?

Author: Duan Yuechu and Huang Xiangjiang

In recent years, the development of global deep-sea oil and gas resources has shown a significant growth and development trend. This field has become the main source of global oil and gas exploration and reserve and production increase, and its development capabilities and technological progress have been significantly improved.

Global deepwater oil and gas production has increased significantly in recent years. For example, from 1990 to 2019, global deepwater oil and gas production increased from less than 300,000 barrels of oil equivalent per day to 10.3 million barrels per day, with an annual growth rate of more than 13%. In addition, the proven reserves of global deepwater oil and gas resources have also increased significantly in the past decade, with a total increase of more than 124 billion barrels of oil equivalent. In terms of the operating depth of global deepwater oil and gas development projects, it has extended from less than 1,000 meters in 1990 to less than 2,000 meters at present. In 2019, global deepwater oil and gas production accounted for more than 20% of global offshore oil and gas production, of which ultra-deepwater project oil and gas production accounted for more than a quarter of global deepwater oil and gas production.

The level of oil and gas exploration and development in the deepwater area of ​​the South China Sea is relatively low, but the resource potential is huge. China has discovered 14 large and medium-sized deepwater oil and gas fields in the northern part of the South China Sea. In order to cope with the challenges of resources, technology and cost, China has put forward a series of suggestions, including strengthening public welfare marine oil and gas geological surveys and evaluations, developing a complete set of deepwater exploration and development engineering technology equipment, and strengthening international oil and gas resource cooperation.

The global offshore oil and gas industry has gradually entered the deepwater development stage, with new offshore oil and gas discoveries exceeding those on land, and steady growth in reserves and production. It is estimated that by around 2035, global offshore oil and gas production will reach 1.865 billion tons of oil equivalent, 954 million tons of offshore crude oil, and 1,079.282 billion cubic meters of offshore natural gas. The advancement of technology and equipment and the reduction of costs have promoted the rapid development of offshore oil and gas business, especially the advancement of exploration and development technology and equipment in the deepwater field, which is the key to the economic and efficient development of deepwater and marginal oil and gas fields.

The report "Global Oil and Gas Exploration and Development Situation and Oil Company Dynamics (2022)" points out that the deepwater field has become the most promising development direction for global oil and gas exploration and development business, and is the main battlefield for exploration and discovery. In the past 10 years, deepwater oil and gas projects have become the core area for global oil and gas reserves and production. Among the 101 newly discovered large oil and gas fields, deepwater oil and gas fields account for 67% of the number and 68% of the reserves. In addition, the report emphasizes that in the context of energy transformation, Chinese oil and gas companies need to seize opportunities, obtain favorable exploration blocks, form effective resource reserves, and gradually realize the transformation from "going out" to "going up" through "one transformation and three strengthenings" to ensure national energy security and high-quality development.

In recent years, China has made remarkable progress in the field of large offshore equipment, among which projects such as "Deep Sea No. 1" and "Anemone No. 1" are particularly eye-catching.

"Anemone No. 1" is Asia's first cylindrical floating production storage and offloading unit, with important technological breakthroughs and application value. This high-end marine equipment consists of nearly 600,000 parts, with a total weight of 37,000 tons and a height of nearly 30 stories. It integrates crude oil production, storage, and external transmission, and is known as the "super energy bowl". The maximum oil storage capacity reaches 60,000 tons, and it can process about 5,600 tons of crude oil every day. In addition, the design life of "Anemone No. 1" is 30 years, and it can operate continuously at sea for 15 years without returning to the dock, which greatly improves economic applicability and reduces the cost of oilfield development and operation.

During the installation process, "Anemone No. 1" faced many challenges. For example, due to its cylindrical structure with a high center of gravity and a large wind-exposed surface, it is prone to rotation, making offshore installation extremely difficult. In order to ensure its stability in the deep sea, the project team installed 12 sets of deep-water suction anchors on the seabed and connected them with 12 special anchor chains. Each anchor chain can withstand a tensile force of up to 2,300 tons, ensuring that it can be firmly rooted even in harsh sea conditions.

Anemone No. 1 (Source: Xinhua News Agency video screenshot)

In addition, the transportation and installation process of "Anemone No. 1" also reflects a high degree of technological innovation. It adopts a transportation method that combines "big ship carrying small ship" and "small ship towing big ship". First, "Anemone No. 1" is loaded onto a large semi-submersible transport ship, transported to the Guangdong anchorage for separation and unloading, and finally towed by a high-powered tugboat to Liuhua Oilfield for back-connection and installation. This process overcomes technical difficulties such as transportation design, program preparation, and complex calculations of super-large structures, and formulates emergency plans for nearly 20 extreme situations.

The successful installation and application of "Anemone No. 1" not only marks a major breakthrough in China's deepwater oil and gas field development, but also has important significance for promoting the economic and efficient development of China's deepwater oil and gas fields. This achievement also reflects China's leading position and technological strength in the global marine engineering field.

In terms of international cooperation, the first exploration well, Guracho-1, in the Alam deepwater exploration block in the Santos Basin of Brazil, jointly drilled by China National Petroleum Corporation and Petrobras, was successfully tested and became one of the top ten crude oil discoveries in the world in the past decade. China National Petroleum Corporation has successfully won bids for many large deep-sea oil and gas projects through cooperation with international companies such as Petrobras, Shell of the Netherlands and Total of France, achieving mutual benefit and win-win results in the field of deep-sea oil and gas development.

In general, the development of deep-sea oil and gas resources around the world is in a rapid development stage, and international cooperation plays an important role in this field. China's development in this field is particularly remarkable, not only has it made significant progress in technology and equipment, but also has achieved effective development and utilization of resources through international cooperation. With the continuous advancement of technology and the deepening of cooperation, the development of deep-sea oil and gas resources is expected to provide more resource support for the global energy market.