孙虎地区烃源岩生排烃史模拟及结果分析

DYNAMIC MODELING AND ANALYSIS OF HYDROCARBON- GENERATING AND EXPULSION OF SOURCE ROCKS IN SUNHU AREA

生排烃史是研究成藏过程的关键环节,本文在恢复埋藏史的基础上,通过建立生排烃史模型,模拟并编制各时期的生排烃强度等值线图并分析其生排烃史。结果表明,孙虎地区存在持续沉降型、早期沉降型和二次沉降型三种生排烃类型。沙三段至东营组沉积末期只在北区和前磨头洼陷中心有少量的烃生成排出;孔二段在沙一段沉积末期生排烃范围有所扩大,东营组沉积末期几乎扩展到全区。本区生排烃总量较少,属贫油区块。

Hydrocarbon-generating and expulsion are critical for the study of hydrocarbon accumulation process. On the basis of reconstructing the burial history, the authors analog and compile the intension chorisopleth of hydrocarbon-generating and expulsion for every stage in order to analyze the generation and expulsion history. The results showed that there are three generation and expulsion styles in Sunhu: persistent subsidence style, forepart subsidence style and secondary subsidence style. The source rocks of the third member of the Shahejie Formation (Es3) generated and expulsed a little hydrocarbon at the end of sedimentation of the Dongying Formation in the north of Sunhu and the center of Qianmotou; the secondary member of the Kongdian Formation (Ek2) enlarged the range of hydrocarbon generation and expulsion at the end of sedimentation of the first member of the Shahejie Formation, and almost involved the whole area at the end of sedimentation of the Dongying Formation. The total amount of hydrocarbon generation and expulsion is low in this area, belonging to an oil-poverty area.