摘要
潜四下亚段是潜江凹陷重要的生储层系,基于地层埋藏史及热史的恢复,定量模拟了潜四下亚段油气的生、排、运、聚特征。结果表明:潜江凹陷现今热流值为40.20～47.99 mW/m2,古热流经历了3个演化阶段,即早期(45.0～41.0 Ma)快速升高阶段、中期(41.0～26.5 Ma)持续升高阶段和晚期(26.5～0 Ma)逐渐降低阶段;潜四下亚段烃源岩现今成熟度Ro为0.45%～1.58%,多数大于0.55%,其底部烃源岩进入生烃门限和达到生烃高峰的时间分别为41.0 Ma和29.0 Ma;潜四下亚段烃源岩的排烃期为33.6～26.5 Ma,26.5～0 Ma排烃量较少;潜江凹陷油气运移路径受流体势和古构造面的控制。潜江凹陷存在7个有利油气聚集区,其中以Ⅰ,Ⅱ,Ⅳ,Ⅶ最有利,主要是因为近源、储集性能好、油气运移动力强和运移距离短。
Lower Member of Eq4 is important bed for hydrocarbon generation and accumulation in Qianjiang Depression.The hydrocarbon generation,migration and accumulation characteristics of Lower Member of Eq4 in Qianjiang Depression are modeled based on the reconstruction of burial and thermal history.The results show that the present heat flow in Qianjiang Depression varies from 40.20 to 47.99 mW/m2 and the palaeo-heat flow experiences three evolutionary stages.At early stage,it increases rapidly from 45.0 to 41.0 Ma.At middle stage,it increases gradually from 41.0 to 26.5 Ma.At late stage,it decreases gradually from 26.5 to 0 Ma.The present maturity（Ro） of hydrocarbon source rocks of Lower Member of Eq4 ranges from 0.45% to 1.58%,most of which is more than 0.55%.In the Lower Member of Eq4,the time of hydrocarbon generation threshold and the time of the peak hydrocarbon generation for the bottom hydrocarbon source rocks are 41.0 Ma and 29.0 Ma.The period of hydrocarbon expulsion from the hydrocarbon source rocks of Lower Member of Eq4 is from 33.6 to 26.5 Ma and the period of less hydrocarbon expulsion is from 26.5 to 0 Ma.The petroleum migration pathways of Lower Member of Eq4 in Qianjiang Depression are controlled by fluid potential and paleostructure surface.Seven favorable oil accumulation zones are identified in Lower Member of Eq4 in Qianjiang Depression.In them,the oil accumulations zonesⅠ,Ⅱ,Ⅳ and Ⅶ are the most favorable zones because their locations are close to the provenance,having good reservoir performance,powerful drive force and short oil migration distance.
出处
《断块油气田》
CAS
2012年第5期554-558,共5页
Fault-Block Oil & Gas Field
基金
国家科技重大专项"断陷盆地油气成藏动力系统与驱动机制研究"(2008ZX05000-006)
关键词
盆地模拟
油气运聚
潜四下亚段
潜江凹陷
basin modeling
hydrocarbon migration and accumulation
Lower Member of Eq4
Qianjiang Depression
