南海北部多类型天然气水合物成藏特征与赋存差异  

Accumulation characteristics and occurrence differences of multitype gas hydrates in the northern South China Sea

作　　者：靳佳澎 王秀娟 邓炜 李清平 李丽霞 余晗 周吉林 吴能友 JIN Jiapeng;WANG Xiujuan;DENG Wei;LI Qingping;LI Lixia;YU Han;ZHOU Jilin;WU Nengyou(Laboratory for Marine Mineral Resources,Laoshan Laboratory,Qingdao 266237,China;MOE Key Lab of Submarine Geosciences and Prospecting Techniques,Frontiers Science Center for Deep Ocean Multispheres and Earth System,College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;National Engineering Research Center of Gas Hydrate Exploration and Development,Guangzhou Marine Geological Survey,Guangzhou 511458,China;State Key Laboratory of Natural Gas Hydrate,CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]崂山实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266237 [2]中国海洋大学海洋地球科学学院深海圈层与地球系统教育部前沿科学中心海底科学与探测技术教育部重点实验室,山东青岛266100 [3]广州海洋地质调查局天然气水合物勘查开发国家工程研究中心,广东广州511458 [4]中海油研究总院有限责任公司天然气水合物国家重点实验室,北京100028

出　　处：《地学前缘》2025年第2期61-76,共16页Earth Science Frontiers

基　　金：国家自然科学基金项目(42206063,42376058)。

摘　　要：近年来,我国在南海北部完成了9个天然气水合物钻探航次,采集了大量三维地震资料,发现了多种赋存类型的天然气水合物,但是不同赋存形态与富集程度的天然气水合物地球物理异常响应及主控因素差异有待厘清。在台西南盆地和琼东南盆地发现了呈烟囱状反射的裂隙充填型水合物与呈强振幅反射的孔隙充填型水合物垂向叠置分布,而珠江口盆地水合物稳定带底界上部广泛发育孔隙充填型水合物。研究认为低孔渗特征、相对细粒沉积层和块体搬运沉积体储层,匹配局部高通量流体供给条件,控制了裂隙充填型水合物赋存;相对低通量流体和相对粗粒储层岩性是孔隙充填型水合物赋存的主要条件,而Ⅱ型水合物、水合物与游离气共存及近期活动水合物系统均与深部来源热成因气及相对高通量流体供给有关。构造沉积背景差异是多类型水合物赋存的主要原因,流体运移通道、运移方式和储层岩性耦合控制天然气水合物富集程度;受晚期岩浆侵入、泥火山构造、隆起构造影响而形成的断层和气烟囱构造控制流体运移与天然气水合物成藏。因而查明不同盆地发育的天然气水合物赋存差异,厘清多类型水合物地质主控因素对于指导高富集天然气水合物藏勘探具有重要意义。Recent gas hydrate drilling expeditions,combined with extensive 3D seismic data,have revealed the widespread occurrence of multiple types of gas hydrates on the northern slope of the South China Sea.However,the anomalous geophysical responses associated with variations in gas hydrate types,accumulations,and their primary geological controls remain poorly understood.Fracture-filling gas hydrates,often linked to cold seep systems,are characterized by chimney-like seismic reflections.In contrast,pore-filling gas hydrates exhibit high-amplitude reflections above the bottom simulating reflector(BSR)and are vertically superimposed with fracture-filling gas hydrates in the Tainan and Qiongdongnan basins.In the Pearl River Mouth Basin,pore-filling gas hydrates are predominantly found near the base of the gas hydrate stability zone.The occurrence of fracture-filling gas hydrates is controlled by relatively fine-grained and mass transport deposit(MTD)reservoirs with low porosity and permeability,which are matched with high-flux fluid systems.On the other hand,pore-filling gas hydrates are primarily controlled by coarse-grained reservoirs and relatively low-flux fluid systems.Recent drilling results suggest that the presence of structure II gas hydrates,the coexistence of gas hydrates and free gas,and active gas hydrate systems are closely associated with the supply of thermogenic gas and high-flux fluids from deep gas sources.The study highlights that the diverse tectonic and sedimentary settings in the northern South China Sea are the primary factors driving the occurrence of multiple types of gas hydrates.The coupling of fluid migration pathways,migration mechanisms,and reservoir lithology plays a critical role in controlling variations in gas hydrate accumulations.Key geological features such as faults,gas chimneys formed by magmatism,intrusive structures,mud volcanoes,and basement uplift significantly influence fluid migration and gas hydrate formation.A comprehensive understanding of the differences in gas hydrate occ

关 键 词：天然气水合物 多类型 流体运移 储层 南海北部 

分 类 号：P618.13[天文地球—矿床学]