【作者】 贾存富；

【导师】 李巍然；

【作者基本信息】 中国海洋大学 ， 海洋地质， 2007， 硕士

【摘要】 孤岛潜山位于渤海湾盆地济阳坳陷东北部的沾化凹陷内,是一个断块型潜山,倾向北东,受孤西、孤南和孤北三条断层的控制。孤岛潜山位于孤北-渤南洼陷和孤南洼陷两个生油洼陷之间,具有双向供油的有利条件。潜山在下古生界经历了多期构造运动,长期处于隆起状态,受风化侵蚀和淋滤作用的影响,岩溶作用广泛发育,形成了奥陶系八陡组或上马家沟组碳酸盐岩风化壳储层和多套下古生界碳酸盐岩储层。孤西断层、孤南断层、孤北断层、不整合面及裂缝系统为油气运移提供了有利的输导体系,而且潜山长期处于隆起状态,成为油气运移的主要指向区。孤岛潜山生储盖组合为下生上储顶盖型,油气成藏属于“新生古储型”。控制孤岛潜山油气聚集和成藏最重要的条件是盖层条件,断层封堵性的变化也决定了油气的运聚和成藏。潜山顶部最为重要的盖层是上第三系东营组泥质岩。然而,东营组沉积末期的构造抬升运动使得潜山顶部东营组被风化剥蚀,形成一个1.84km2的“天窗”,潜山主体直接与下第三系馆陶组底部孔渗性好的砂砾岩体接触,构成了油气向上逸散的通道。“天窗”形成时期,也是渤南洼陷沙四段烃源岩大量排烃期,同时也是渤南、孤南两个洼陷沙三段烃源岩开始成熟的时期,此后沙三段、沙一段相继排出油气,这个“天窗”一直是油气向上的“逃逸通道”。这造成孤岛碳酸盐岩潜山主体不能形成大规模的油气聚集和成藏。断层在孤岛潜山成藏中也起了重要的作用,断层活动期也是烃源岩大量排烃期,断层垂向不封堵性造成油气沿断层向上覆第三系运移。因此,孤岛潜山虽然是长期继承性隆起,又生于生油洼陷之间,是油气运聚的主要指向区,但不一定是最有利的油气富集带。盖层成为决定潜山油气聚集成藏的最重要的条件,断层封堵性的变化也决定了油气的运聚和成藏。更多还原

【Abstract】 Located at Zhanhua depression in the northeast of Jiyang Depression, Bohaiwan basin, Gudao buried-hill is a fault-block buried-hill. The buried-hill is inclined to northeast and controlled by Guxi, Gunan and Gubei faults, it stands between the two oil source sags of Gubei-Bonan sag and Gunan sag, has the advantageous location and favorable condition for supply and migration of oil and gas.The low Paleozoic carbonates in the buried-hill have suffered multistage tectogenesis and uplifted, which resulted in extensive karstification and formed karstic reservoir. The Guxi, Gunan and Bubei faults, unconformable surface and fracture systems are composed of the good migration systems for petroleum and gas, and made the buried-hill be the main area of hydrocarbon and migration direction. The source-reservoir-caprock assemblage of Gudao buried-hill is low source-up reservoir-top caprock. The hydrocarbon pool belongs to "new source to old reservoir".The important factor to control the hydrocarbon accumulation and pool is the condition of caprock. The most important caprock at the top of the buried-hill is Paleocene Dongying formation. However, the Dongying formation at the top of the buried-hill was denuded by the tectonic uplift during the late of Dongying formation. It formed a "clerestory window’’ with 1.84 km2. The main body of the buried-hill directly contacted with the overlain sandy block of Guantao formation, which formed escape route for petroleum and gas. The time of "clerestory window" formation is also the period of Es3 maturation in Bonan and Gunan sags. It is the escape route that made the main body of the buried-hill not be large-scale accumulated by the hydrocarbon. The faults play a important part at the petroleum accumulations of The buried-hill. The movement periods of the faults are also the time of hydrocarbon escape. The vertical unsealing of fault made the lots of hydrocarbon migration to the overlain Tertiary era.Therefore, the Gudao carbonate buried-hill is uplifted and located between rich petroleum source sags, it was the main area for hydrocarbon migration but not the most advantageous hydrocarbon accumulation zone. The caprock condition is the most important factor of the buried-hill petroleum and gas accumulation. The change of fault sealing can also decide the hydrocarbon migration, accumulation and reservoir formation.更多还原