An Evaluation Diagram of Effective Source Rocks in the First Member of Qingshankou Formation in Northern Songliao Basin and Its Implication
详细信息
- 责任者：Huo Qiuli (Research Institute of Exploration & Development ; Daqing Oilfield Company Limited ; Daqing 163712 ; China) ; Zeng Huasen
- 刊名：Acta Petrolei Sinica
- 出版年：2012
- 卷期：33(3)
- 关键词：烃源岩 ; source rocks ; 松辽平原 ; Songliao Plain
- 页码：p.379-384
- 图表：3 illus., 27 refs.
- 分类号：1003
- issnNo：ISSN0253-2697
- isbnNo：CN11-2128/TE
摘要
An effective source rock is defined as sedimentary rocks that have generated and expulsed petroleum.An expulsion critical value is reached when the petroleum generation mass equals the remained mass in a source rock.An identification diagram for effective source rocks in the first member of the Qingshankou Formation(K2qn1) in the northern Songliao Basin was established based on the mass conservation principle.This diagram integrates an organic carbon content,organic type and maturity of source rocks,while these parameters in the conventional source rock assessment are considered somewhat separately.Thus,the diagram can be used to quickly and directly assess the effectiveness and expulsion potential of a source rock.The diagram shows that a source rock with high content of organic matter is more ready to expulse petroleum than that with low content of organic matter,moreover,the former requires a comparatively low maturity to generate petroleum.When TOC is lower than 0.4%(i.e.the lower limit of TOC needed for a source rock),petroleum expulsion cannot occur in source rocks.The diagram was then applied to the assessment of the K2qn1 source rock in the central depression of Songliao Basin,which indicates that the Qijia-Gulong Depression,the south of the Changyuan,and the Sanzhao and Wangfu Depressions all have experienced mass expulsion of petroleum,while the Heiyupao Depression has a limited potential of petroleum expulsion.The accuracy and effectiveness of the diagram were verified by the intensity of petroleum occurrence in these areas,indicating that the diagram can be used to optimize exploration targets and decrease the risk of exploration.