【摘要】 依据地震资料,结合区域对比分析,对西沙海域生物礁进行了识别。结果表明,平面上生物礁主要分布在岛礁区、盆地内部构造凸起带和盆地边缘隆起区。岛礁区发育中新世、上新世、更新世和全新世生物礁,未被碎屑沉积地层覆盖,不具备成藏条件,是无效勘探区。盆地内部构造凸起带发育中新世和上新世生物礁,与构造高点匹配。礁基以下发育砂岩储层,成藏组合为构造—碎屑岩—生物礁复合型油气藏,具有近油源、构造—岩性复合型圈闭和生储盖配置关系好等特点,是最有利的勘探方向。盆地边缘隆起区在前寒武纪变质岩基底之上发育中新世、上新世和/或更新世生物礁,成藏组合多为单一的生物礁型油气藏,有时可能形成基岩潜山—生物礁型油气藏,这类圈闭虽然远离油源,但油气可以通过断裂、不整合面、渗透地层等输导系统长距离运移至储层,因此这类油气藏也具有较好的勘探前景。更多还原

【Abstract】 Based on seismic data and combining with regional correlation and analysis,the recognition is carried out for biogenetic reef in Xisha sea area. The results showed that the main planar distribution of biogenetic reef is in island area,tectonic heights in the interior of basin and upheaval in margin of basin.The biogenetic reefs developed in Miocene,Pliocene,Pleistocene and Holocene in island area were not overlaid by clastic sedimentary strata and is exploration-invalid area because without reservoir condition.The biogenetic reefs developed in Miocene and Pliocene in tectonic heights in the interior of basin,matching with structural heights,developing sandstone reservoir under reef rock basement,where the reservoir combination is complex structural-clastic-biogenetic reef reservoir and characterized by near oil sources,complex structural-lithologic trap and good configuration among oil sources,reservoir and cap rocks,is favorable exploration direction.The biogenetic reefs developed in Miocene,Pliocene and Pleistocene in the upheaval in margin of basin was developed in Precambrian metamorphics basement,the reservoir combination of which is unique biogenic reef reservoir,sometimes forming basement berriedhill-biogenetic reef reservoir,which has good exploration prospect because the oil and gas can migrate to the reservoir after long distance migration through such transmission system as faults,unconformity surfaces and permeable formation although far from the oil sources.更多还原