摘要
气源运聚通道与天然气水合物富集成藏关系密切。利用准三维地震资料并结合钻探成果,深入研究了神狐海域GMGS3钻探区高饱和度水合物站位气源运移疏导通道地质地球物理特征及其控藏作用。结果表明:高饱和度水合物产出站位发育多种类型运移疏导通道,且与BSR空间耦合关系较好;紧邻BSR之下为强振幅反射,强振幅下部游离气体充注现象明显,表明水合物稳定域下部存在气体运移的通道,且深部气体向浅层发生了运移。深大断裂、底辟及气烟囱构成了沟通深部热解气及浅层生物气与浅层温压稳定域的垂向通道,在这些通道上方可以直接形成水合物;浅部滑塌面、水道砂及海底扇构成的高孔渗连续性砂体为浅层生物气及深部运移而来的部分热成因气横向运移通道,气体的侧向运移扩大了气体供给范围,增加了矿体横向展布规模。文章认为,天然气运移疏导系统与其他成藏要素匹配良好的构造和区域是勘探高饱和度水合物的有利目标。
Abstract:Migration pathways of gas have close relationship with migration and accumulation of natural gas hydrate.Based on high resolution quasi-3D seismic data,and combined with practical drilling results,the authors studied the geological and geophysical features of gas migration pathways and their controlling effects associated with high saturation gas hydrate in GMGS3drilling sites of Shenhu area.The results show that multiple types of migration pathways are developed in high saturation gas hydrate drilling sites in GMGS3drilling area,which have favorable corresponding relation with BSR in space.Enhanced reflections occur closely beneath the BSR,and gas charging phenomena are obvious under the enhanced reflection,indicating migrating pathways exist under the gas hydrate stability zone and deep gas has migrated to shallow formations through those pathways.Deep faults,mud diapirs,gas chimneys act as vertical migrating pathways that connect deep thermogenic gases with shallow biogenic gas and pressuretemperature stability zones,and gas hydrate can be formed and accumulated just over those pathways.Shallow slump surface and high continuous sand bodies composed of channel sandstones and submarine fans provide lateral migrating pathways for the migration of shallow biogenic gas and partial thermogenic gas from deep formations,which expands the range of gas supply and increases the gas hydrate distribution scales.It is concluded that tectonic structures and regions with favorable coupling relationship between hydrocarbon migrating system and other elements are prospective targets with high saturation gas hydrate.
作者
张伟
梁金强
苏丕波
尉建功
沙志彬
林霖
梁劲
黄伟
ZHANG Wei;LIANG Jinqiang;SU Pibo;WEI Jiangong;SHA Zhibin;LIN Lin;LIANG Jin;HUANG Wei(MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, Ministry of Land and Resources,Guangzhou 510075, Guangdong, China;School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082,Guangdong, China)
出处
《中国地质》
CAS
CSCD
北大核心
2018年第1期1-14,共14页
Geology in China
基金
中国博士后科学基金项目(2017M622655)、国土资源部海底矿产资源重点实验室开放基金项目(KLMMR-2017-A-13)、国家自然科学基金青年科学基金项目(41602149)及中国地质调查局项目(DD20160211)联合资助.
关键词
天然气水合物
高饱和度
运聚通道
GMGS3航次
站位选择
神狐海域
南海北部
natural gas hydrate
high saturation
migration pathway
GMGS3 expedition
drilling site selection
Shenhu area
northern South China Sea
