摘要
为了了解神狐海域天然气水合物成藏的气体来源及聚集特征,根据过SH2井区高分辨率地震剖面构建了该区地质模型,并进行了天然气水合物成藏模拟。在恢复SH2井区地史和热演化史的基础上,利用EASY%Ro模型计算了SH2井区烃源岩的成熟度演化史,结合探区采样成果对水合物的气源特征进行了初步探讨。结果表明:深部发育的2套烃源岩(古近系文昌组和恩平组)演化程度均较高(Ro>2%),处于产干气阶段,热解生气潜力巨大;浅部新近系珠江组、韩江组、粤海组和万山组基本处于未成熟—低成熟阶段(Ro<0.7%),有机质丰度较高,是生物气的烃源岩,具有生物生气的巨大潜力。同时,神狐海域地质构造复杂,断层与底辟发育,这些断裂和底劈构造成为连接浅部水合物稳定域和气源的桥梁,为生物成因气和深部热解气的运移提供了良好的通道。当气源和天然气水合物稳定域的时空匹配得当,在适当的地质条件下便可形成天然气水合物。初步预测该区天然气水合物资源潜力巨大,是勘探远景区。
In order to recognize gas sources and accumulation patterns of gas hydrate in the waters of Shenhu,we built a geologic model based on the high-resolution seismic profile tied to the SH2 well and simulated the accumulation of gas hydrate.The geologic history and thermal evolution history of the SH2 wellblock were restored,the EASY% Ro model was used to define the thermal evolution history of source rocks in the SH2 well,and the characteristics of gas source were preliminarily discussed in combination with the sampling results in the exploratory area.The following conclusions were obtained.Sources rocks in both the deep Palaeogene Wenchang and Enping formations have high thermal maturity(Ro>2%),and are in dry gas generating stage with a huge potential of pyrolysis gas.In contrast,source rocks in the shallow Neogene Zhujiang,Hanjiang,Yuehai and Wanshan formations are basically immature and/or low mature(Ro<0.7%),are relatively high in organic abundance,and have a huge potential of biogas.In addition,faults and diapires are highly developed in Shenhu waters.They act as the bridges connecting the shallow gas hydrate stable zones with the gas sources,and are pathways for the migration of the shallow biogas and deep pyrolysis gas.When the temporal and special combination of gas sources and gas hydrate stable zones is favorable,gas hydrate can accumulate in suitable geologic conditions.Preliminary prediction results show that the study area has huge gas hydrate resource potentials,thus it is a prospect for future gas hydrate exploration.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2010年第10期103-108,共6页
Natural Gas Industry
基金
国家重点基础研究发展计划(973计划)项目"南海北部天然气水合物成藏的气源条件研究"(编号:2009CB219501)
国土资源部公益性行业科研专项项目"天然气水合物成藏的控制因素研究"(编号:200811014)
国家自然科学基金项目"南海北部深水盆地油气渗漏系统与天然气水合物富集机制研究"(编号:40930845)
关键词
天然气水合物
气源对比
有机质成熟度
生物气
运移通道
油气藏形成
烃源岩
神狐海域
gas hydrate,gas-source correlation,organic matter,maturity,biogas,migration pathway,hydrocarbon accumulation,hydrocarbon source rock,Shenhu waters
