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利用地震、测井与地温资料综合分析了南海北部东沙海域可能存在的天然气水合物的分布特征 .研究表明 ,在东沙海域地震剖面上出现似海底反射层、弱振幅带等天然气水合物分布标志 ,在声波测井曲线上呈现高速、速度倒转等天然气水合物存在特征 .似海底反射层的深度与 1 1 44站位 ,及平均地温梯度资料得出的稳定带厚度较吻合 .1 1 44站位与 1 1 48站位似海底反射层距海底较深 ,分别为 6 5 4m与 475m .在 1 1 44站位附近 ,弱振幅带的顶界可能代表含天然气水合物沉积层的顶界 ,约在 45 0m左右 .
The distribution characteristics of gas hydrates possibly existing in Dongsha sea area of northern South China Sea are comprehensively analyzed by using the data of earthquakes, well logging and geothermal data. The study shows that the distribution signs of natural gas hydrate like seafloor reflection layer and weak amplitude band appear in the seismic section of Dongsha Sea, The characteristics of gas hydrate, such as high velocity and reverse velocity inversion, are present on the acoustic logging curve, and the depth of the seafloor reflecting layer agrees well with the steady zone thickness obtained from 1114 stations and the average geothermal gradient data. The seabed reflecting layers resembled 1148 stations deeper than seafloor, which were respectively 654m and 475m. In the vicinity of 1144 stations, the top of the weak amplitude band may represent the top boundary of gas hydrate-bearing sediments, Around 45 0m.