南海海域新生界沉积盆地天然气成藏条件及资源前景

000年以来，南海油气勘探开发快速发展，特别是深水区获得了重大天然气发现，但对该区的天然气资源认识程度较低，出现了勘探实践与南海资源评价结果不符的情况。因此，需要系统开展南海海域天然气资源评价，科学地认识南海海域天然气资源潜力。在归纳南海油气勘探新进展及油气地质新认识的基础上，总结了构造型、生物礁地层型、深水沉积岩性型及基岩潜山型4类天然气成藏模式，将台西南、北部湾、珠江口、琼东南、莺歌海、中建南、双峰、万安、南薇西、北康、曾母、文莱沙巴、南薇东、礼乐及西北巴拉望等15个主要沉积盆地作为资源评价对象；选择“以多参数类比法为主、以成因法和统计法为辅”的资源评价方法，建立了万安、文莱沙巴和珠江口等3个类比刻度区，代表断陷、走滑和前陆3类不同类型的沉积盆地，通过刻度区精细解剖，系统获得了南海天然气资源面积丰度等关键参数，最终利用特尔斐法综合，预测15个主要沉积盆地的天然气地质资源量为31.85×10¹²m³，明确了南海常规天然气勘探潜力及未来勘探方向。

Accumulations and resource prospects of natural gas of Cenozoic basins in the South China Sea

The hydrocarbon exploration and development in the South China Sea has developed rapidly since 2000，especially in the deep-water areas (water depth >500m).High temperature and high pressure are generally developed，and the source rock is mainly composed of marine-continental transitional coal-bearing strata，supplemented by terrigenous marine mudstone，and natural gasreservoirs are the major hydrocarbon discoveries.The results of hydrocarbon exploration are inconsistent withthose for the resource evaluation in the South China Sea.Therefore，it is necessary to carry out natural gas resource evaluation systematically tounderstand the potential of natural gas resources scientifically in the South China Sea.On the basis of summarizing the new progress of hydrocarbon exploration in the South China Sea and the new understanding of petroleum geology，this paper summarizes four different types of natural gas accumulation models that are related to tectonic，bioreef strata，deep-water sedimentary lithology and bedrock buried hill lithology.We consider 15 major deep-water sedimentary basins as the target for resource evaluation.We use the resource evaluation method which is based on multi-parameter analogy method and supplemented by generative and statistical method.Three analog scale areas such as Wanan，Brunei Sabah and Pearl River Mouth Basin are established，and they represent three different types of sedimentary basins (trap，strike and foreland-basins).We also obtain the key parameters such as hydrocarbon accumulation conditions and abundance of natural gas resources，and finally use the Delphi method to predict the natural gas geological resources of 15 major sedimentary basins (31.85 trillion cubic meters).Finally，we define the geographical，planar and spatial distribution and exploration potential of the natural gas resources in the South China Sea.