Genetic Types Classification of Tight Oil System and Its Exploration Significance of China
Min Zheng, Jianzhong Li, Hongbing Xie, Weipeng Yan, Xiaozhi Wu, Tao Yang, and Xiaoming Chen
PetroChina Research Institute of Petroleum Exploration & Development, Beijing, China
As the new focus of global petroleum exploration, tight oil exploration has received much attention in recent years due to its huge resource potential. The tight oil refers to an oil that accumulates in source rocks in a free or adsorbed state or in tight sandstones and carbonates interbedded with or adjacent to source rocks. Generally, this oil accumulation has not yet experienced a large-scale, long-distance migration.
Many excellent research results has been found in the reservoir properties, petroleum properties, and development technology in recent years, but little attention has been paid to the tight oil system and its genetic types classification in China.
Based on the clarity of the tight oil concept and connotation, we studied carefully about the structure bedding, lithology, sedimentary fancies, lithofacies and paleogeography, et al. According to this genetic drive mold research thinking, we proposed ten key indices to evaluate the tight oil, established tight oil system, and research the reservoir classification and genetic types classification of tight oil. Tight oil reservoirs of China can be generally divided into 3 different types based on porosity and permeability, while the tight oil itself can be also classified into 3 types depending on the genetic correlation of a close contact between tight reservoirs and source rocks, i. e., tight oil in lacustrine carbonate rocks; tight oil in deep-lake gravity flow sandstones and tight oil in deep-lake delta sandstones.
AAPG Search and Discovery Article #120098©2013 AAPG Hedberg Conference Petroleum Systems: Modeling the Past, Planning the Future, Nice, France, October 1-5, 2012