摘要
准确评估新西兰Hikurangi边缘Tuaheni滑坡复合体(TLC)区域的天然气水合物含量与储层分布对TLC慢滑移现象与产生机制的解释有重要作用。本文分析了IODP372航次U1517站位测井和取心数据,发现在局部地层纵波速度增加(>1.7 km/s)和电阻率升高(>1.5Ω·m)的104~160 mbsf层段存在天然气水合物,其中112~114、130~145和150~160 mbsf层段饱和度相对较高。根据岩性划分了不同井段对应的矿物成分含量,用于纵波速度模型计算,并利用简化三相介质(STPE)和改进的Biot-Gassmann模型(BGTL)分别估算了104~160 mbsf层段的天然气水合物饱和度,平均饱和度分别为5.2%和6.0%,最高饱和度分别为22.7%和21.6%。同时,与阿尔奇公式估算的水合物饱和度比较,在104~160 mbsf层段3种方法估算的饱和度值随深度变化相似,天然气水合物平均饱和度相近(约6.0%),在130~145 mbsf层段的水合物平均饱和度最高(约8.5%)。本研究使用两种声速模型和更为精细的参数估算饱和度,其估算结果更为可靠,可为Tuaheni滑坡复合体慢滑移现象研究提供良好的基础数据支撑。
Accurate assessment of natural gas hydrate saturation and reservoir distribution in the Tuaheni landslide complex(TLC)area on the Hikurangi margin,New Zealand plays a critical role in explaining the creeping TLC phenomenon and its forming mechanisms.Gas hydrates are discovered in the interval from 104 mbsf to the BGHS at 160 mbsf based on the logging-while-drilling(LWD)and coring data from the site U1517 located on the extensional and creeping part of the TLC.Elevated P-wave velocity(>1.7 km/s),electrical resistivity(>1.5Ω·m),and the high saturation intervals occur in 112~114 mbsf,130~145 mbsf and 150~160 mbsf respectively.The mineral components of different well intervals are used to calculate the P-wave velocity,to estimate the gas hydrate saturation of the 104~160 mbsf interval with the simplified three-phase equation(STPE)and the biot-gassmann theory by Lee(BGTL)models,and the average saturation was 5.2%and 6.0%and the highest was 22.7%and 21.6%,respectively.Adoption of the new method made it more efficient to get BGTL model parameters.Compared with the hydrate saturation estimated by the Expedition 372 from the Archie equation was used,the average gas hydrate saturation is similar in the 104~160 mbsf interval(about 6.0%)and about 8.5%in the interval of 130~145 mbsf.In this study,two sound velocity models were used to estimate the hydrate saturation of U1517,making the results more reliable.The accurate estimation of the gas hydrate saturation and distribution at site U1517 will provide basic data for simulation of the creeping TLC phenomenon on the Hikurangi margin.
作者
陈杰
胡高伟
卜庆涛
王秀娟
景鹏飞
刘昌岭
郭洋
王自豪
CHEN Jie;HU Gaowei;BU Qingtao;WANG Xiujuan;JING Pengfei;LIU Changling;GUO Yang;WANG Zihao(Laboratory of Gas Hydrate,Ministry of Land and Resources,Qingdao Institute of Marine Geology,Qingdao 266071,China;Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266071,China;China University of Petroleum,Qingdao 266580,China;Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2020年第6期159-168,共10页
Marine Geology & Quaternary Geology
基金
国家自然科学基金“南海富含有孔虫沉积物中水合物形成及其声学响应机理研究”(41474119)
“裂隙充填型水合物声学响应机理研究”(41976077)
国家重点研发计划课题“水合物试采目标综合评价技术应用示范”(2017YFC0307602)。
