辽河坳陷雷家致密油烃源岩评价标准探讨

Discussion of Leijia Source-Rock Evaluation Criteria in Liaohe Depression

为确定雷家地区沙四段致密油烃源岩评价标准及有利勘探区,通过对该区烃源岩岩性、TOC、有机质成熟度、有机质类型、生烃潜力等指标综合分析,认为该区烃源岩TOC高、成熟度适中,有机质类型好,生油潜力大,确定了该区沙四段致密油烃源岩优质源岩岩性主要为碳酸盐质泥页岩、泥质云(灰)岩及黏土型泥页岩,长英质泥页岩次之,并根据烃源岩有机质类型、TOC、Ro、ST等指标确定Ⅰ、Ⅱ、Ⅲ类烃源岩的评价标准。落实该区Ⅰ类烃源岩主要分布于陈家洼陷主体,面积为54.9 km^2;Ⅱ类烃源岩主要分布于陈家洼陷的外缘,面积约为153.0 km^2;Ⅲ类烃源岩主要分布于陈家洼陷的东侧,面积约为51.0 km^2。确定该区致密油Ⅰ类有利勘探区集中在陈家洼陷内,Ⅱ类有利勘探区主要为陈家洼陷的侧缘及北部台安洼陷主体,Ⅲ类有利勘探区为陈家洼陷的东侧。该研究对确定下一步有利勘探目标具有一定的指导意义。

The source-rock lithology, TOC, organic matter maturity, hydrocarbon generation potential and other aspects are analyzed to determine the Shahejie-4 tight oil source-rock evaluation criteria and favorable exploration areas in Leijia. Analysis indicates that the source-rock in this area is characterized by high TOC, medium maturity, favorable organic matter type and high oil-generation potential. Shahejie-4 tight oil source-rock is considered as favorable source-rock in this area and the corresponding lithology is dominated by carbonate shale, argillaceous dol- omite （limestone） and clay shale, followed by felsic shale. The source-rock in this area is classified into Category - Ⅰ , Category- Ⅱ and Category-Ⅲ according to the organic matter type, TOC, Ro , ST and other indicators. Cate- gory- Ⅰ source rock in this area mainly distributes in the main body of Chenjia Depression and the corresponding area is 54. 9 km^2. Category-Ⅱ source rock in this area mainly distributes in the outer edge of Chenjia Depression and the corresponding area is 153.0 km^2. Category-Ⅲ source rock in this area mainly distributes in the east side of Chenjia Depression and the corresponding area is 51.0 km^2. The favorable exploration areas of Category-Ⅰ mainly distribute within Chenjia Depression. The favorable exploration areas of Category- Ⅱ mainly distribute in the side edge of Chenjia Depression and the main body of Taian Depression in the north. The favorable exploration areas of Category-Ⅲ mainly distribute in the east side of Chenjia Depression. This research could provide certain guidance for the identification of favorable exploration areas in this area.