In recent years, China's energy demand has been rising day by day, conventional oil and gas resources have been rapidly consumed, and the contradiction between oil and gas supply and demand has become prominent.Seizing new opportunities for the development of unconventional oil and gas resources is not only a need to ensure national energy security, but also an inevitable choice for our country based on the endowment of oil and gas resources.

The national "14th Five-Year Plan for the Modern Energy System" proposes to actively expand the exploration and development of unconventional resources, increase the development of shale oil, shale gas, and coal bed methane, and include resource areas such as Jimusar shale oil, Ordos Basin shale oil, dense gas, and Songliao Basin Daqing Gulong Shale oil in key energy security projects.

Four drilling rigs of Shengli Petroleum Engineering carried out drilling and construction in the test well group of Niubei District 1 of the national shale oil demonstration Zone

As a representative of unconventional oil and gas, shale oil and gas has become one of the most strategic alternative energy sources in our country and an important battlefield for future oil and gas exploration and development.

Recently, the Sixth Oil and Gas Geological Engineering Integration Forum was held in Beijing.With the theme of “Integrated models, methods and green intelligent Technologies of Oil and Gas geological Engineering” and the purpose of “China issues, global vision, exchange and sharing”, the forum attracted a number of domestic and foreign experts, as well as representatives from related enterprises, universities and scientific research institutions to participate in the discussion.

China's shale oil and gas exploration has made many breakthroughs, and industrial development has entered the "fast lane”

At the beginning of the 21st century, a major breakthrough in the theory and technology of shale oil and gas exploration and development in North America was made, and shale oil and gas turned out, which has since changed the world's energy landscape.

Our country is rich in shale oil and gas resources.According to estimates by the U.S. Energy Information Administration (EIA), China's shale oil technology can recover about 4.393 billion tons, ranking third in the world; according to the evaluation results of the Ministry of Natural Resources, China's shale gas technology can recover 21.8 trillion cubic meters of resources, ranking among the forefront of the world.In the current environment, the huge shale oil and gas resources are of great strategic significance to enhance the domestic oil and gas supply capacity and ensure energy security.

Since 2010, my country has attached great importance to shale gas exploration and development, and the policy follow-up has been more timely.In 2012, the Ministry of Finance and the National Energy Administration issued the "Shale Gas Development and Utilization Subsidy Policy" to subsidize shale gas production; in 2013, the "Shale Gas Industry Policy" was issued to implement market pricing for shale gas, encourage the establishment of shale gas demonstration zones, and promote Sino-foreign cooperation. It also proposed to reduce and reduce mineral resource compensation fees and mineral rights royalties for shale gas mining enterprises, and to study and introduce incentive policies such as resource tax, value-added tax, income tax, and exemption from customs duties on imports of key equipment.With the in-depth advancement of shale gas exploration and development, policies at the national and local levels have also been dynamically followed up and adjusted.In 2021, the National Energy Administration will strengthen the exploration and development of shale oil in the “14th Five-Year Plan” energy and oil and gas development plan, and propose a series of measures to promote the green development of shale oil.

The successive introduction of policies has played a good role in promoting the development of shale oil and gas in our country.Guo Xusheng, academician of the Chinese Academy of Engineering, deputy Chief geologist of Sinopec, and president of the Institute of Petroleum Exploration, introduced that after more than 10 years of exploration and research, China's shale gas reserves and production have achieved rapid growth: eight marine shale gas fields such as Fuling, Weiyuan, Changning, Zhaotong, Luzhou, Weirong, Yongchuan, and Qijiang have been proven in the Sichuan Basin, with a cumulative proven geological reserve of more than 2.9 trillion cubic meters; shale gas production has increased from 0.25 billion cubic meters in 2012 to 24 billion cubic meters in 2022, accounting for 24 billion cubic meters. More than 11% of total natural gas production.China's shale gas industry has achieved a major breakthrough from scratch, and it has become the most important and realistic application area for the development of natural gas in our country.According to the planning goals of the National Energy Administration, the development of China's shale gas industry will be further accelerated during the “14th Five-Year Plan” and “15th Five-Year Plan” periods. It is expected that shale gas production will reach 80 billion to 100 billion cubic meters in 2030, and domestic shale gas resources are expected to enter the stage of large-scale commercial development.

In terms of shale oil, although my country started late, it has developed rapidly. Major breakthroughs have been made in shale oil exploration and development in Ordos, Junggar, Songliao, Bohai Bay, Beibu Gulf and other basins.In June 2021, Changqing Oilfield completed a large shale oil field with proven geological reserves of more than 1 billion tons in the Ordos Basin; in August 2021, Daqing Oilfield made a major strategic breakthrough in the exploration of Gulong shale oil, with 1.268 billion tons of new oil predicted geological reserves; in November 2021, Shengli Oilfield made multiple breakthroughs in the exploration of shale oil in Jiyang, with the first batch of reported predicted petroleum geological reserves of 458 million tons; in July 2022, Jiangsu Oilfield made a major exploration breakthrough in shale oil exploration wells in the Northern Jiangsu Basin. , Added 110 million tons of predicted shale oil reserves; in July 2022, a major breakthrough was made in offshore shale oil exploration in the Southwest Depression of the Beibu Gulf Basin, with an estimated resource volume of 800 million tons... Up to now, the country's shale oil has proven geological reserves of 1.306 billion tons, controlled reserves of 241 million tons, and predicted reserves of 3.778 billion tons, totaling 5.325 billion tons of tertiary reserves, showing huge development potential.At the same time, positive progress has been made in the construction of national demonstration zones, and three national demonstration zones for shale oil have been established in Jimusar, Gulong and Jiyang.With the blessing of technological accumulation, China's shale oil production has continued to increase, reaching 3.4 million tons in 2022, a record high.

Accelerate theoretical and technological innovation, and promote the development of shale oil and gas to achieve economies of scale

If our country's first shale revolution was “terrestrial shale oil production”, the discovery of the Daqing Oilfield, etc., broke the “China's oil-poor theory”, then the second shale revolution is “terrestrial shale oil production”, moving from conventional oil, which accounts for 20% of resources, to unconventional oil, which accounts for 80%.

Unlike conventional oil and gas, the development of shale oil and gas is like collecting blood in capillaries, and it needs to “squeeze” out the oil and gas from the crevices of the stones.To realize the “second revolution” of shale in China, the key lies in continuous breakthroughs in theoretical understanding, iterative innovation of engineering technology and oil and gas equipment.

Yuan Shiyi, an academician of the Chinese Academy of Engineering, introduced that the essence of the North American shale revolution is to promote the industrial revolution through the scientific and technological revolution. Through years of basic research and experiments, especially breakthroughs in core technologies such as multi-stage fracturing of horizontal wells, it has broken the traditional oil and gas theoretical understanding that shale cannot be used as an oil and gas reservoir, and used a revolutionary “man-made oil and gas reservoir” method to make it a shale oil and gas reservoir with great industrial extraction value.Compared with the United States, although China's shale oil and gas resources have great potential, the geological conditions are more complex, deeper buried, and more difficult to extract, and large-scale commercial development faces greater challenges.

In recent years, as Sinopec, PetroChina and other companies have continuously strengthened the promotion of shale oil and gas development demonstration projects and technical research, China's shale oil and gas has made a series of important advances in basic research, development countermeasures, and engineering technology.In terms of theoretical understanding, the pore development and maintenance mechanism of deep-water amphibious shale has been revealed, and a new understanding of “overpressure gas enrichment” of deep-water shale gas has been formed; the law of land-based shale oil enrichment and the main control factors of high yield in our country have been clarified.In terms of engineering technology, through continuous iteration and continuous optimization, the supporting technology for excellent and fast drilling and completion of shale oil and gas and the integrated fracturing transformation technology of geological engineering have been initially formed; the integrated fracturing design software of geological engineering has been developed and built from scratch, and the replacement of localization has been gradually realized; a three-dimensional development technology strategy has been formed, and the overall fracturing development effect of shale oil and gas three-dimensional well network has been remarkable, and it has entered the stage of large-scale development.In terms of key equipment, the level of digital intelligence of domestic drilling and completion and ultra-high-power all-electric fracturing equipment has been continuously improved. Breakthroughs have been made in high-temperature and high-pressure high-precision measurement and control devices such as rotary guidance system, MWD (measurement with drilling), and LWD (logging with drilling), and industrial applications have been realized.

Guo Xusheng said that the key research directions of shale oil and gas in the future should still focus on basic and key issues. One is to increase exploration efforts and establish a hierarchical evaluation system for shale oil and gas resources; the second is to study synchronous three-dimensional development technology to reduce the negative impact of the development sequence on the development of multi-layered systems; the third is to form an integrated geological engineering operation and cooperation mechanism to implement the whole life cycle management of shale oil and gas, improve the efficiency of drilling and fracturing operations, and realize speed, efficiency and cost reduction.

The abundance of terrestrial shale oil resources in our country is 400,000 to 900,000 tons/square kilometer, which is 1/2 to 1/3 of that of the United States, and the degree of resource implementation is low, and the resource discovery rate is only 4%.In terms of large-scale cost-effective development of terrestrial shale oil, Yuan Shiyi believes that there is still a lack of effective research methods and theoretical understanding of the whole life cycle development, insufficient key technological innovation to increase single-well production and EFFICIENCY (estimate the final recovery), and the technical system to improve the recovery rate has not yet been established.He suggested that one is to systematically carry out the potential evaluation of various types of shale oil resources across the country, focusing on the evaluation of technical and economically recoverable resources, and predict the economic limit production of shale oil at different oil prices and the corresponding recoverable resources, so as to provide a reliable resource basis for the sustainable design of phased production, replacement and development scale; the second is to deepen the research on the survival state and flow mechanism of different types of shale oil, and provide a scientific basis for the selection of development methods and the formulation of technical strategies; the third is to develop integrated and differentiated well network deployment technologies for geological engineering, innovate reservoir transformation technologies, and build higher-quality “artificial reservoirs”; the fourth is to establish overall optimization and development methods , Upgrade and form a mining model and supporting technology system that can be popularized on a large scale to improve the drilling effect and efficiency; fifth, accelerate the research and testing of early replenishment of formation energy, and form a multi-medium technology to greatly improve the recovery rate of shale oil, supporting the maximum utilization of resources and high-quality sustainable development.