On the 25th, PetroChina announced that its Changqing oilfield had discovered a 1 billion-ton Qingcheng oil field in Qingyang, Gansu Province. A spokesman for Changqing Oilfield said that in 2018 the country will produce 189 million tons of crude oil and have a reserve size of 1 billion tons of Qingcheng Oilfield, which will have a production capacity of 3 million tons in the next 3-4 years. Qingcheng Oilfield is one of a series of large oil fields in China in recent years, what is the reason why China has made frequent breakthroughs in oil and gas exploration?
According to the Blue Book of China’s Oil and Gas Industry Development Analysis and Outlook Report (2018-2019) (hereinafter referred to as the Blue Book), released in March this year, China has made significant discoveries in oil and gas exploration in recent years. Last year, PetroChina made major exploration discoveries in xinjiang’s Quanger Basin, and the Tarim Basin and Sichuan Basin scored new breakthroughs in oil and gas exploration, and discovered and implemented a number of large-scale reserves in ordos, Chaidamu, Bohai Bay and Songliao Basins. CNOOC has successfully evaluated a number of large and medium-sized high-quality integrated oil and gas fields in China, including 19-6 and 29-6 in The Bohai. Among them, the 19-6 gas field test in The Central China obtained high-quality high-yield oil and gas flow, and determined that the proven geological reserves of natural gas exceed100 billion cubic meters.
So why are these large oil and gas fields with amazing reserves discovered today? Fang Zheng medium-term futures researcher Xu Yuanqiang 28 in an interview with the Global Times, said that the important oil and gas basins in China are mainly located in the Ordos Basin, Tarim Basin and Bohai Basin. Important large-scale oil fields are also found in these basin areas, and Changqing oil field is currently the largest oil field in China, mainly located in the Ordos Basin. With the development of three-dimensional seismic exploration technology, imaging logging and horizontal well drilling technology, more and more difficult to explore and difficult to develop in China’s oil fields have been found. At present, the large oil fields found are “difficult bones”, because Changqing oil field has low seepage, low pressure, low abundance and other characteristics, so it is necessary to carry out multiple drilling logging analysis of the region, combined with three-dimensional geological modeling and reservoir numerical simulation and other modern scientific and technological means, in order to have a major discovery of the region.
Xu Yuanqiang said that as exploration technology improved, the domestic exploration but did not find oil fields in the area will indeed find large oil fields. “Since many oil and gas fields are known as hidden reservoirs, it is difficult to explore without technical upgrading, and previously conventional oil and gas fields are back-slope or broken-block oil and gas reservoirs,” Xu explained. With the development of oil fields, this conventional oil and gas reservoir is less and less, but more is the deep basin oil and gas reservoir or shale oil and dense reservoirs, these reservoirs have low-altitude low-penetration low saturation and other characteristics, the general development cost is higher. As technology improves, many oil and gas companies have been able to cut costs, so large fields that were previously hard to find can now be discovered. “