南海陆坡天然气水合物饱和度估计  

ESTIMATION OF GAS HYDRATE SATURATION IN THE CONTINENTAL SLOPE,THE SOUTH CHINA SEA

作　　者：王秀娟[1] 吴时国[1] 郭璇[2] 徐宁[1] 

机构地区：[1]中国科学院海洋研究所 [2]中国石油勘探开发研究院西北分院地球物理所,兰州730020

出　　处：《海洋地质与第四纪地质》2005年第3期89-95,共7页Marine Geology & Quaternary Geology

基　　金：中国科学院知识创新工程重要方向性项目(KZCX3-SW-219)

摘　　要：基于双相介质理论和热弹性理论,建立了沉积层纵波速度与天然气水合物饱和度、弹性性质及地层孔隙度之间的关系.通过对比饱和水的理论P波速度与实际P波速度,可以得到天然气水合物饱和度.根据ODP184航次的电阻率、声波速度、密度等测井资料以及地质资料,初步推断南海陆坡存在天然气水合物.根据声波测井的纵波速度估算出南海1146和1148井天然气水合物饱和度分别为孔隙空间的25%～30%和10%～20%,1148井个别沉积层天然气水合物饱和度可达40%～50%.沉积层的纵波速度与饱和水速度差值越大,天然气水合物饱和度越高.Sedimentary layer velocities are related with gas based on Two-Phase theory and thermoelastic theory. A be obtained by comparing the theoretical P-wave velocity hydrate saturation, elastic properties and porosity qualitative estimate of gas hydrate saturation can for full-water saturation to actual P-wave velocity. On the basis of resistivity,sonic logging,density data and geology data in ODP184,there exist gas hydrates in the continental slope of the South China Sea. Contents of gas hydrate at ODP sites 1146 and 1148 in South China Sea are 25%-30% and 10%-20% of the pore space respectively. At site 1148,1ocal formation saturation comes to 40%-50%. Normally, the larger the difference between P-wave velocity in the normal sediment layer and that in gas hydrate-bearing sediment layer, the richer the gas hydrate saturation.

关 键 词：天然气水合物 纵波速度 声波测井 饱和度 南海 

分 类 号：P744.4[天文地球—海洋科学]