Changqing Oilfield has built the largest tight gas production base in China with high quality

On July 22, a horizontal well deployed by the Changqing Oilfield Tight Gas Project Team in Wushenqi area of Inner Mongolia was successfully completed, with a drilling depth of 8,528 meters and a horizontal section length of 5,256 meters, setting a new record for the longest horizontal section of an onshore horizontal well in Asia. Last year, the tight gas production of Changqing Oilfield accounted for 70% of the country, and the largest tight gas production base in China has been built.

Experts revealed that the overall evaluation of the Ordos Basin has 16.38 trillion cubic meters of natural gas resources, of which 80% are tight gas. At present, the tight gas resources in the Ordos Basin are the most abundant in the country, and the tight gas production in Changqing accounts for more than 1/4 of China's total oil and gas production. As the most typical representative of China's tight gas field development, what are the successful experiences of Changqing tight gas development, and where is the direction of key research in the next step?

Liu He, academician of the Chinese Academy of Engineering, pointed out that the development of tight gas in Changqing, represented by the Sulige gas field, depends on two points, management innovation and technological innovation. In recent years, the Sulige gas field has made a huge breakthrough in horizontal well volume fracturing, from well pattern deployment to benefit development, which has further promoted the development of the entire oil and gas field, especially tight gas, and played a huge role in ensuring national energy security.

Due to the special reservoir and geological conditions of the Ordos Basin, the oil wells are almost "oil at the mouth, but not flowing from the mouth", and the production of gas wells is generally low and decreasing rapidly. After several generations of efforts, Changqing people have overcome one technical difficulty after another, and built an oil field with an annual output of one million tons into the largest oil and gas field in the country. After 50 years of arduous exploration, especially in the past 20 years, Changqing Oilfield has vigorously promoted natural gas development, continuously innovated the management mode and organizational model, and made breakthroughs in tight gas exploration and development, mainly with four landmark achievements: innovating the theory of large-scale continental tight gas accumulation, and discovering China's largest gas field with reserves of 4.5 trillion cubic meters - Sulige gas field; Through the three models of in-source, out-source and contact, the multi-layer trillion-cubic-meter atmospheric fields in the eastern part of the Ordos Basin, such as Shenmu rice fat, were implemented. Innovate the geological theory of natural gas accumulation in weathered crusts, and discover trillions of cubic meters of gas fields represented by Jingbian gas field; Innovate the theoretical understanding of stratigraphic storage and tight gas accumulation, and promote the discovery of new trillion cubic meters of atmospheric fields in the southern part of the Ordos Basin, such as Qingyang, Yichuan and Huanglong.

Shi Daohan, general manager and deputy secretary of the Party Committee of Changqing Oilfield Company, introduced that Changqing tight gas aims to improve the production of a single well and reduce development costs, relying on the major special projects of the state and the group company, and has formed 30 main development technologies in 6 categories, which has effectively promoted the development of tight gas economies of scale. During the "13th Five-Year Plan" period, the investment in the construction of 100 million cubic meters of tight gas production capacity in Changqing fell by 12.8%, and the internal rate of return was more than 9.5%.

For the tight future of Changqing, Zhao Wenzhi, an academician of the Chinese Academy of Engineering, is full of expectations. He said: "In the next step, the exploration layout and planning of the Changqing gas area can improve the fine description of the gas reservoir in the more complex areas with lower abundance and production in addition to the existing main gas reservoirs, and further rely on technological progress to reduce costs and increase the production of single wells." For gas fields that have already been developed, enhanced oil recovery through technology. At present, the recovery rate of tight gas in Changqing is about 30%~40%, and the recovery rate of conventional gas field is about 70%, if it can be increased by 10 percentage points, it is of great significance for the stable production and production of Changqing gas field. ”

"In the future, there is great potential for the exploration and development of Paleozoic tight gas in the Ordos Basin." Fu Suotang, executive deputy director of China Petroleum Consulting Center, pointed out that "there is a lot of room for improvement in terms of resource reserves, single well production and oil recovery. ”

Jia Ailin, chief expert of China Petroleum Exploration and Development Research Institute, believes that the next step of tight gas is to pursue the development effect and level, and how to further improve the recovery rate is the key, if it can be increased from the current 30% to 50%, it will open up a new world for the development of tight gas benefits in China.

Disclaimer: The above content is reprinted from China Petroleum News