辽河坳陷滩海地区烃源岩特征与评价

Characteristics and Evaluation of Hydrocarbon Source Rocks in Offshore Area of Liaohe Depression

通过对辽河坳陷滩海地区暗色泥岩进行有机地球化学分析,研究了有机质丰度、类型和成熟度,并评价烃源岩有效性。研究表明:沙一二段暗色泥岩有机质丰度达到好烃源岩标准,东营组和沙三段暗色泥岩达到较好烃源岩标准;烃源岩有机质类型以Ⅱ2型和Ⅲ型为主,沙河街组烃源岩丰度和类型都好于东营组;烃源岩生油窗深度范围为2500~5000 m,西部凹陷的沙河街组为有效烃源岩,以生油为主,东部凹陷沙河街组和东营组下部为有效烃源岩,生油为主兼生气。鉴于有关滩海地区的生烃潜力研究较少,本次研究为油气勘探提供了基础地质资料,并为辽河坳陷陆上油气勘探部署做对比参考。

The organic geochemical analysis of dark mudstone in offshore area of Liaohe depression was carried out to study the abundance,type and maturity of organic matter and evaluate the availability of source rock.The results show that the organic matter abundance of the dark mudstone in the first and the second member Shahejie formation meets the standard of best source rock,and the dark mudstone in the Dongying formation and in the third member Shahejie formation meets the standard of better source rock.Hydrocarbon source rock organic matter type is given priority to the second of typeⅡand typeⅢ.Shahejie formation hydrocarbon source abundance and types are better than Dongying formation.The depth range of oil source rocks is from 2500 metres to 5000 metres.Shahejie formation in the west sag has effective source rocks,mainly producing oil.Shahejie formation and lower part of Dongying formation in the east sag have effective source rocks,mainly producing oil and generating gas.Considering that there are few researches on hydrocarbon generation potential in relevant intertidal areas,the study provides basic geological data for oil and gas exploration,and provides a comparative reference for onshore oil and gas exploration deployment in Liaohe depression.