CHARACTERISTICS AND RESOURCE POTENTIAL OF OIL SHALE IN CHINA

Based on the results of the National Oil Shale Resource Evaluation in China conducted from 2003 to 2006, and combined with the new exploration progress in recent years, the characteristics and resource potential of oil shale in China have been systematically studied in this paper. Oil shale resources in China are abundant, with deposits mainly found in the continental environment and, secondarily, in marine-continental facies. The color of oil shale is black to grayish black, black to gray brown or gray to dark gray. In general, the darker the color, the higher the quality of oil shale. The most common minerals in oil shale are clay minerals, quartz and feldspars. The concentration of organic carbon in Chinese oil shale is high, between 7.48 and 38.02%. By organic genetic type, oil shale can be divided into sapropelic, humosapropelic and saprohumic oil shale. Oil shale used for industrial purposes has a medium to high oil yield and high ash content. Oil shale resources in China are mainly concentrated in 20 provinces and autonomous regions, 50 basins and 83 petroliferous shale areas. Total oil shale resources are estimated at approximately 978 billion tons, i.e. about 61 billion tons of in-place shale oil, mainly distributed throughout eastern and central China and the Qinghai-Tibet Region in western China. This paper outlines the distribution of oil shale deposits in China with respect to depositional basin type, and oil shale age and grade. Oil shale in China was deposited mainly in extensional and intra-plate basins during the Mesozoic and the Cenozoic. The size of the basins diminishes from older to younger deposits. Oil shale resources that yield shale oil more than 5% by weight account for about 72% of the rock's total resources in the country.