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Oil and gas exploration marches into the deep

Posted:2020/8/24 10:03:01

Recently, the Energy Administration issued the "Guiding Opinions on Energy Work in 2020" (referred to as "Opinions"). The "Opinions" emphasized that multiple measures must be taken simultaneously to enhance oil and gas safety guarantee capabilities. Among them, "increase the intensity of oil and gas exploration and development" is listed as the first task.

Recently, the Energy Administration issued the "Guiding Opinions on Energy Work in 2020" (referred to as "Opinions"). The "Opinions" emphasized that multiple measures must be taken simultaneously to enhance oil and gas safety guarantee capabilities. Among them, "increase the intensity of oil and gas exploration and development" is listed as the first task.

“Oil prices are so low, it’s good to buy oil abroad. Why should we emphasize oil and gas exploration?” In the face of various doubts in the society, Jin Zhijun, academician of the Chinese Academy of Sciences and director of the Key Laboratory of Shale Oil and Gas Enrichment and Effective Development, said China Science Daily stated that like food and water, oil and gas have become a necessity for human life and a strategic material related to national security. Ensuring the national oil and gas security cannot rely solely on imports, and increasing exploration and development efforts based on domestic efforts will be an important task at the national strategic level.

The consensus of many oil and gas exploration experts is that deep, deep sea and shale oil and gas will become the main directions of future oil and gas exploration, and insisting on efficient exploration and profitable development is also an inevitable choice for the sustainable development of the oil and gas industry.

Oil and gas exploration "from shallow to deep"

Increasing domestic oil and gas exploration and development efforts has continued to receive great attention from inside and outside the industry. In recent years, the continuous increase in policies and the repeated progress in the exploration field have injected a "cardiotonic agent" into my country's oil and gas industry. The steady increase in output of many old oilfields such as Shengli Oilfield has also actively played the role of "ballast stone".

"Oil and gas growth is still at its peak, and my country's oil and gas reserves and production growth are also at its peak. This peak period is estimated to continue until 2050." Kang Yuzhu, a member of the Chinese Academy of Engineering and a petroleum geologist, predicts that my country's crude oil output is expected to reach 2.3 in 2050. Billion to 250 million tons, and the output of natural gas is as high as 350 billion to 400 billion cubic meters.

In an interview with China Science Daily, Kang Yuzhu pointed out that from the perspective of global oil and gas development trends, my country's oil and gas exploration in the future will shift from east to west, from land to ocean, and from medium-shallow layers to medium-deep and ultra-deep layers. In addition, with the development of exploration and development theory and technological advancement, the search for oil and gas resources in deeper and older layers has become an important goal of oil and gas companies.

According to the reporter's understanding, deep-seated oil and gas resources have been the main body of growth in the world's proven reserves in the past decade, constantly breaking through the lower limit of effective resources to maintain depth. From 2008 to 2018, the world added 23.4 billion tons of oil equivalent of proven oil and gas reserves in formations deeper than 4,000 meters, more than 60% of the world's new oil and gas reserves in the same period, and the maximum oil and gas drilling depth reached 12,869 meters.

Deep water has also become the focus of recent oil and gas reserves, and major discoveries are mainly concentrated in passive continental margin basins on both sides of the Atlantic Ocean, East Africa, and the Mediterranean Sea. From 2008 to 2018, the world’s proven reserves of oil and gas in oceans totaled 21.7 billion tons of oil equivalent, accounting for 68% of the world’s new proven reserves of oil and gas, of which deep water and ultra-deep water accounted for more than 40% of the world’s new recoverable reserves.

Jin Zhijun said that my country's deep oil and gas exploration has expanded from 4000 to 5000 meters in the past to 6000 to 8000 meters. In addition, deep marine shale gas and continental shale oil at a depth of 3,500 meters will be key breakthrough areas for China's oil and gas exploration.

However, bravely breaking into the deep exploration restricted zone is also an "extreme challenge" for the entire oil and gas industry.

Overcome the "stuck neck" technique

The entire process of oil and gas exploration is like a coordinated battle of thousands of troops, which is a very large system engineering. But if you want to advance to the depths of the earth, you must first face various engineering and technical problems.

"The distribution law of deep-seated oil and gas is different from that of shallow layers. With the increase of burial depth, the tightness of rocks is also increasing. For high production, a complete set of drilling and fracturing technologies suitable for deep-seated oil and gas exploration is required. For my country, it faces challenges from equipment to technology." Jin Zhijun said frankly that the rotary steering drilling system at the core of oil and gas exploration is the "stuck neck" technology that my country urgently needs to overcome.

The rotary steerable drilling system is a new cutting-edge automated drilling technology. The drill bit can travel freely through thousands of meters of hard rock underground like a "snake", and eventually hit the target of oil and gas reservoirs accurately. The requirements of this technology are even greater than that of missiles. The guidance technology is more stringent.

"The missile's medium is air. After calculating various parameters, effective control can be achieved. The underground medium is changing at any time, which requires extremely high drilling technology." Jin Zhijun said that currently most of the domestic rents are rented. Foreign equipment has increased the cost for oil and gas exploration and development. Therefore, the next step of the rotary steering drilling system will be one of the key core technologies that my country must overcome.

In addition, for shale gas exploration and development, Gao Deli, an academician of the Chinese Academy of Sciences and a professor at China University of Petroleum (Beijing), told the Chinese Journal of Science that the “well factory” with cluster-type horizontal wells as the basic feature is highly efficient for shale gas at home and abroad. The development of mainstream engineering operation mode, and to create a large-scale "well factory", it is necessary to challenge the limits of large-reach horizontal well engineering operations.

"Under certain subjective and objective constraints, any extended-reach horizontal well that can actually be built has an allowable limit value for its borehole length, which we call the extension limit of extended-reach horizontal wells." Gao Deli pointed out, At present, many small “well factories” (mostly 4-well or 6-well) have been built in my country, and hundreds of shale gas horizontal wells have been built in total. However, none of the wells is an extended-reach horizontal well as defined above. Restricting the creation of large-scale "well factories", it is urgent to seek leapfrog technological breakthroughs by strengthening interdisciplinary research.

Gao Deli pointed out that due to many constraints such as the complexity of technical equipment and the economic efficiency of business operations, there is still a large gap between my country's engineering operation capability and technical equipment level compared with the international level.

Low-cost technology is the key

"Without technological progress, it is impossible to achieve economic and effective development." Jin Zhijun emphasized that low-cost technology will become an important direction for the next scientific and technological progress of the entire petroleum industry.

He said that for low-mature, high-viscosity, low-fluidity shale oil, it is necessary to study its enrichment and flow mechanism in the future, and establish a set of low-cost underground in-situ upgrading technologies, including underground fracturing technology and in-situ heating. Technology, anti-corrosion technology, etc.

Jin Zhijun also pointed out that low oil price fluctuations will inevitably promote the industry's transformation from the past "resource expansion" technological progress to the "cost reduction and efficiency increase" technological progress. In the process, information technology and artificial intelligence are reshaping the pattern of the oil and gas industry.

“Personally predicts that the application of a new generation of information technology with artificial intelligence, big data, and blockchain technology as the mainstay can reduce the cost of the petroleum industry by 20% to 30%.” Jin Zhijun said.

Kang Yuzhu also stated that future oil and gas exploration will require cross-border integration of new technologies, new materials, and intelligent information technology. At the same time, it is necessary to increase the research and development of ocean and deepwater oil and gas exploration and development technologies and equipment. my country should focus on the national oil and gas exploration needs from 2020 to 2035, focus on strategic goals, highlight the key points of research, break through the "stuck neck" technology, and form disruptive technologies through cross-border integration, so as to master the core key technologies in the strategic field.

Gao Deli suggested that the country should establish an advanced safety monitoring and guarantee system for natural gas development and utilization as soon as possible (including technical standards, operating mechanisms, regulatory systems and target responsibilities, etc.) to ensure that natural gas is being drilled, exploited, long-distance pipeline transportation, storage and reserve , The safety and reliability of each link such as network transmission and distribution and terminal use, as far as possible to reduce or avoid the occurrence of major natural gas safety accidents.

Based on the domestic and international market demand, Gao Deli suggested that the state should adopt policy guidance or even administrative promotion, based on the relevant technology and human resources of the existing national oil and gas group companies, through shareholding reorganization and other models, and refer to international oil and gas engineering technology service companies. With successful experience in business operations and organization management, establish and cultivate internationally competitive oil and gas engineering technology service companies as soon as possible, and allow two or more independent legal entities to exist at the same time to maintain the vitality of the oil and gas engineering technology market.

"Such a professional technical service company should have the basic characteristics of the integration of technology R&D and service and the internationalization of market operations. It should target similar international technical service companies and be able to serve as a domestic oil and gas company (or investment subject). Foreign oil and gas exploration and development investment projects provide strong technical support, and can obtain huge technical service income, and strive to gradually form a virtuous circle." Gao Deli said.