水深对海洋天然气水合物双BSR的控制作用

DISCUSSION ON THE RELATIONSHIP BETWEEN WATER DEPTH AND DOUBLE-BSR IN MARINE GAS HYDRATE-BEARING SEDIMENTS

通过对海洋天然气水合物双BSR控制因素的了解,结合南海实际情况,认为双BSR主要存在于生物气和热解气气源充足的海区。按照Sloan的CSMHYD程序分别计算了不同盐度、不同水深条件下双BSR之间的厚度差,结果发现沉积物盐度的影响作用较小,而水深的影响作用较大,表现为双BSR之间的厚度差随水深的增加而减小,因此,推测水深是控制双BSR分布的一个重要因素。

To discuss the possible controlling factors on the double-BSR of marine gas hydrate bearing sediments, the BSR distributions of South China Sea were analyzed. The results show that the double- BSRs probably exist in the sea areas where the biogenic and thermogenic gas sources are sufficient. On the basis of the Sloaffs CSMHYD software, thickness differences between BSR1 and BSR2 with dif ferent pore water salinities were calculated, the results show that the salinities may have a little impact on it, while the water depth has important influence over it, displaying that the thickness difference becomes smaller along with water depth deeper. Therefore, it is inferred that the water depth could be one of the major factors on the double-BSRs＇ distribution in marine gas hydrate-bearing sediments.