摘要
南海北部陆坡深水区新生代发育两种类型凹陷：一类为大型继承性断-坳叠合型凹陷,其裂谷期、热沉降期和新构造期沉积都很发育,且在垂向上叠合分布;另一类是断陷型凹陷,主要发育裂谷期沉积。大型继承性断-坳叠合型凹陷中发育3套古近系烃源岩,烃源岩体规模大,以生气为主;主力储层是渐新统滨浅海三角洲砂岩、新近系低位扇砂岩;区域盖层是区域性海相泥岩;凸起及低凸起上披覆构造型圈闭发育,凹陷内凹中隆构造圈闭发育。白云凹陷油气具有垂向运移和辐射状运移双重特征,琼东南盆地深水区具有从烃灶向南汇聚运移的特征。丰富的烃源、高效的输导条件、大量的构造圈闭及其有利的配置关系表明,深水区的大型继承性断-坳叠合型凹陷具有巨大的勘探潜力。相对于大型继承性断-坳叠合型凹陷,断陷型凹陷古近系烃源岩规模小,圈闭类型单一且规模小,其油气勘探潜力还有待进一步证实。
The deepwater area in the northern continental margin of South China Sea developed two types of sags in the Cenozoic.The first one is the large inherited rift-depression superposition sag that developed sediments of the rifting sequence,thermal subsidence sequence and Neo-tectonic sequence.The other one is the rifting sag that developed mainly sediments of the rifting sequence.The large inherited rift-depression superposition sag has three sets of Paleogene source rocks.The source rocks are the large scale mudstone that mainly generates natural gas.The chief reservoirs here are the shallow sea delta sandstone in the Oligocene and the low-stand fan sandstone in the Neogene.The regional marine mudstones are the regional cap rocks.The drape traps develop in the uplifts and low uplifts while the dome traps develop in the interior.Gas migrated vertically and radiatly from hydrocarbon-kitchen to adjacent structual ridges in Baiyun Sag of Pearl River Mouth Basin.The petroleum migrated and accumulated from the hydrocarbon-kitchen to the south in deepwater area of Qiongdongnan Basin.Abundant hydrocarbon source rocks,good migration conditions,lots of structural traps and favorable allocation in the deepwater area showed the great hydrocarbon exploration potential of the large inherited rift-depression superposition sag in the deepwater area.Compared with the large inherited rift-depression superposition sag,there are limited scale of the Paleogene source rocks and single trap type in the rifting sag.So the hydrocarbon exploration potential in this type of sag needs to be optimized.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2010年第4期521-527,共7页
Acta Petrolei Sinica
基金
国家重点基础研究发展规划（973）项目（2009CB219400）
国土资源部全国油气资源战略调查与评价项目（XQ-2004-05）、（XQ-2007-05）
国家科技重大专项（2008ZX05025）联合资助
关键词
南海北部
深水区
新生代
油气地质
热盆
构造圈闭
油气勘探潜力
northern South China Sea
deepwater area
Cenozoic
petroleum geology
＂hot＂ basin
structural trap
hydrocarbon exploration potential
