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.
