东沙海域生物礁的地震反射特征及油气勘探意义

南海北部东沙海域早中新世时期发育大量的生物礁，蕴藏着丰富石油天然气资源。此文以该区域高分辨率的地震数据为基础，重点分析该区域生物礁的类型及其空间展布特征，结合近年来区域烃源岩研究结果，完善了东沙海域生物礁的油气成藏模式。分析结果表明:东沙海域的生物礁类型主要有台地边缘礁、块状礁、层状礁和塔礁共4种类型，这些生物礁主要分布在东沙隆起的西南部、南部等区域。油气钻探结果表明，东沙隆起南部白云凹陷始新统和渐新统也具有良好的生烃能力。结合烃源岩与生物礁以及疏导体系空间配置关系，指出东沙海域的生物礁具有惠州凹陷和白云凹陷双向供源的油气成藏模式，白云凹陷北部的生物礁也具有良好的油气潜力，是今后重要的油气勘探方向。

Seismic Reflection Characteristics of Reefs in Dongsha Sea Area and Significance of Oil and Gas Exploration

A large number of reefs developed in the Dongsha sea area of the northern South China Sea during the early Miocene, which are rich in oil and natural gas resources. Based on the high resolution seismic data in this area, this paper mainly analyzes the types and spatial distribution characteristics of reefs in the region. Combined with the research results of regional source rocks in recent years, the hydrocarbon accumulation model of reefs in Dongsha sea area has been perfected.The results show that there are four types of reefs in Dongsha sea area:platform marginal reefs, massive reefs, layered reefs, and tower reefs. These reefs are mainly distributed in the southwest and south of Dongsha Uplift.The results of oil and gas drilling show that the Eocene and Oligocene of Baiyun Sag in the southern part of the Dongsha Uplift also have good hydrocarbon generation capacity. Based on the spatial distribution relationship between source rocks, reefs and drainage systems, it is pointed out that the reefs in Dongsha sea area have the bidirectional oil and gas accumulation in Huizhou Sag and Baiyun Sag. The reefs in the northern part of Baiyun Sag also have good potential for oil and gas. They are important directions of oil and gas exploration in the future.