中文摘要：

以松辽盆地南部为研究区,基于物质平衡法对源岩的排烃强度进行定量评价,利用PetroMod软件的超压模块对源岩内超压进行评价。通过建立源岩排烃强度与残余有机碳含量及超压的关系,根据拐点确定出岩石排烃量2 mg/g、残余有机碳含量0.8%、超压1 MPa为致密油源岩的下限,提出岩石排烃量8 mg/g、残余有机碳含量2.0%、超压7 MPa为致密油优质源岩的界限。据此,将致密油源岩划分为优质源岩（Ⅰ类）、低效源岩（Ⅱ类）、无效源岩（Ⅲ类）。利用致密油源岩的下限及分级评价标准对松辽盆地南部致密油有利区分布范围进行评价,结果显示优质源岩对致密油分布具有显著的控制作用,优质源岩发育区及邻近层位是致密油富集的有利区。

英文摘要：

With southern Songliao Basin as the target area, the hydrocarbon expulsion intensity of source rocks was quantitatively evaluated based on the material balance method. Under the ＂Overpressure＂ module of PetroMod software, the overpressure history of the source rocks was evaluated. According to the relationships among hydrocarbon expulsion intensity, residual organic carbon content and overpressure within source rocks and related inflection points, the lower limits of tight oil source rocks were determined： hydrocarbon expulsion amount of per unit mass rock 2 mg/g, residual hydrocarbon content 0.8%, and overpressure 1 MPa. The source rocks with hydrocarbon expulsion 〉 8 mg/g, a residual organic carbon content 2.0%, and overpressure 7 MPa were defined as the limits of excellent source rocks. As a result, the tight oil source rocks can be divided into three types, excellent source rocks （type I ）, inefficient source rocks （type II ） and invalid source rocks （type Ill）. The evaluation has been made for favorable areas distribution range of tight oil in Southern Songliao Basin according to the lower limits and grading evaluation criteria of tight oil source rocks. The result shows that the excellent source rocks have an obvious control on the distribution of tight oil, areas with excellent source rocks and nearby formations are favorable for the accumulation of tight oil.