摘要
迄今为止，在渤海浅层（上第三系馆陶组一明化镇组及埋深小于2000m的下第三系）发现的油气地质储量已占到海域总储量的94％，所发现的油气田大多分布在凸起上，气田和油气田中的天然气以气层气略占优势，溶解气次之，渤海22个凹（洼）陷中有20个被证实为生烃凹（洼）陷，从而为油气藏的形成奠定了雄厚的物质基础，早期控凹（洼）断层和异常发育的晚期断层为油气向浅层运移提供了良好通道，上新世末发生的渤海运动形成了一批浅层构造圈闭（如反转背斜与披覆背斜），为油气聚集提供了良好的场所，良好的泥岩盖层特别是湖相泥岩盖层对油气保存起了重要作用，油气运聚动平衡也是油气藏形成的重要因素之一，海域与周围陆区烃源岩母质类型的差异，使得海域有一定数量的天然气生成，海域较高的沉积速率与郯庐断裂活动造成的高地温梯度和异常压力是生成凝析气和裂解气的主要原因，渤海浅层不但具有广阔的石油勘探前景，也具有相当的天然气勘探前景.
Up to now,the geologic hydrocarbon reserves discovered in shallow intervals(Neogene Guantao Formation-Minghua zhen Formation and Paleogene deep less than 2,000m) have accounted for 94% of the total reserves in Bohai Sea. Most oil and gas fields are discovered in uplifts,and gas and oil gas fields are slightly dominated by reservoir gas and contain less solution gas. In the 22 sags,20 have proved to be hydrocarbon kitchens, laying solid material foundations for hydrocarbon accumulation. The early faults controlling sags and late faults abnormally developed can serve as path for hydrocarbon migration to shallow intervals. A number of structures, such as inverted anticlines and drape anticlines,formed during the latest Pliocene Bohai Movement,can become excellent hydrocarbon traps. For preservation of hydrocarbon accumulation,there are good mudstone seals,particularly the lacustrine clay seals. In addition, a dynamic balance between hydrocarbon migration and accumulation is an important factor favourable to formation of oil and gas pools. In terms of organic matter in source rocks, the offshore area is different from onshore,so natural gas has generated in Bohai Sea. The generation of condensate and cracking gas can be attributed to high geothermal gradient and abnormal pressure induced by offshore higher sedimentation rate and movement of Tancheng Lujiang Fault. Therefore,there are both a wide oil prospectiveness and a considerable gas potential in the shallow intervals of Bohai Sea.
出处
《中国海上油气（地质）》
2000年第6期367-374,共8页
China Offshore Oil and Gas(Geology)
关键词
渤海浅层油气
成藏条件
生烃凹陷
晚期断层
构造圈闭
油气运聚
动平衡
Bohai Sea
shallow interval
hydrocarbon kitchen
late fault
structural trap
dynamic balance between hydrocarbon migration and accumulation
