Emerging Oil Shale Plays in China
Li, Qinghui; Chen, Mian; Jin, Yan; Wang, Fred; Hou, Bing
The investigation of regional source rocks, paleogeography and tectonic evolutions reveals China has vast potential oil shale plays spanning from Pre-Permian to Neocene and covering over 15 provinces with proved reserves of 33 billion. Chinese Oil shale Plays have their own characters that most of potential oil shales are deposited during Cenozoic Era in continental environment and deposited from older to newer formation along with west-north line. Most of these oil shales are buried from shallow to medium depth and suitable for producing.
The high grade oil shale deposits of China mainly distribute in Cenozoic small-scale fault basin of assembling coal, while the low oil rate of oil shale with huge resources deposits mostly distribute in Upper Cretaceous large-scale petroleum depression basin. The formation of oil shale deposit s in small-scale fault basin of China is mainly affected by tectonic and climate function, while the formation of Oil shale deposits in large-scale depression basin relates to global anoxic event, which often changes with the sea level tightly. A new evaluation system was established with considering of different age and buried depth. About 90 sedimentary basins were identified with oil shale, mainly around Songliao Basin, Ordos Basin, Bohai Bay Basin, Junggar Bain, Maoming Basin, Liaohe-Fushun Basin and Shangzhi-Yilan-Luobei Basin et al. Oil contents between 5% and 10% are the main potential reserves in China. Paleogeography and tectonic evolution studies reveal that sea level and anaerobic environment have a notably relationship to oil shale distribution from Southeast to Northeast China. Proved reserves in Cenozoic are over 11 billion tons, while in Mesozoic 180 billion tons and in Paleozoic over 5 billion tons. The oil shales have decent brittle mineral content, almost no smectite and usually have sandstone interbeds and have more clay mineral content than gas shales. The Meso-Cenozoic oil shales with high TOC and medium or low Ro are emerging oil shale plays, while the shallow organic rich shales are usually biogenic shale gas plays.
China has long been exploiting and using oil shale for over 80 years mainly in refining shale oil, producing natural gas and burning as fuels directly. These emerging shale plays have been gradually demonstrated by historical and recent drilling.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013