| The exploration and development of tight oil has greatly changed the structure of oil resources in the southern Songliao Basin, so it is necessary to carry out systematic resource evaluation. The oil resources in the southern Songliao Basin are mainly distributed in middle-shallow layers, in which three reservoir assemblages of lower, middle, and upper develop. Conventional oil is widely distributed in the three reservoir assemblages, but tight oil only in the lower assemblage. As for the conventional oil, we set up three types of calibration zones including structure, structure-lithology, and lithology, and divide the study area into 13 units based on reservoir types and assemblages, and evaluate the resources mainly with statistics and analogy method. As for the tight oil, we set up one calibration zone and divide the study area into 3 units based on permeability, and evaluate the resources with methods of classified resource abundance analogy and small cell volume. The total amount of oil resource in the southern Songliao Basin is about 32.2 ×108 t , including 22.5×108 t of conventional oil and 9.7×108 t of tight oil. The total amount of remaining oil resources is about 10×108 t , including 5.7×108 t of conventional oil, which mainly develop in oil layers of Gaotaizi and Saertu, and 9.7×108 t of tight oil, which mainly develop in oil layers of Fuyu. The Gaotaizi oil layer in Daqingzijing area and Fuyu oil layer in Qian’an area are the key exploration zones in the near to medium term. |
