南海北部东沙海域浅层沉积物孔隙水地球化学示踪深部水合物发育特征

发布时间：2018-06-24 08:14

  本文选题：孔隙水地球化学 + 天然气水合物模拟　； 参考：《地球化学》2017年03期

【摘要】：天然气水合物是一种具有广阔前景的清洁能源资源,但目前对海洋天然气水合物预测方法有多种,利用浅层沉积物孔隙水地球化学示踪沉积层深部天然气水合物的方法,可以为海域天然气水合物前期普查提供一个廉价有效的途径。利用南海北部东沙海域D-5、D-8和D-F站位沉积物孔隙水硫酸根离子、溶解无机碳、钙离子和镁离子在剖面上的分布特征,模拟了3个站位甲烷供给通量及天然气水合物可能的发育特征。计算结果表明,D-5、D-8和D-F站位到达甲烷-硫酸根氧化界面的甲烷通量分别为11.97×10~( 3) mol/(m~2·a)、5.98×10~( 3) mol/(m~2·a)和26.45×10~( 3) mol/(m~2·a),天然气水合物形成的最大温度梯度分别为0.058℃/m、0.020℃/m和0.149℃/m,计算的天然气水合物顶界深度分别为海底之下170~197 m、378~386 m和79~98 m,甲烷通量对天然气水合物顶界影响大,温度对天然气水合物发育顶界影响较小。结合研究区似海底反射层发育特征判断,D-5和D-F站位深部沉积层中可能有天然气水合物,D-8站位应该没有天然气水合物发育。
[Abstract]:Natural gas hydrate is a kind of clean energy resource with broad prospect. However, there are many methods for predicting marine gas hydrate, which uses shallow sediment pore water to trace deep gas hydrate in sediments. It can provide a cheap and effective way for the preliminary survey of natural gas hydrate in the sea area. The distribution characteristics of sulfate ion, dissolved inorganic carbon, calcium ion and magnesium ion in sediment pore water of D-5 + D-8 and D-F stations in Dongsha sea area, northern South China Sea, were used, and the distribution characteristics of dissolved inorganic carbon, calcium and magnesium ions in the profile were analyzed. The methane flux at three stations and the potential development characteristics of natural gas hydrate were simulated. The calculated results show that the maximum temperature gradient of gas hydrate formation at D-5 ~ (-8) and D-F stations to the methane-sulfate oxidation interface is 11.97 脳 10 ~ (-3) mol/ (mt2a) 5.98 脳 10 ~ (3) mol/ (mt2a) and 26.45 脳 10 ~ (3) mol/ (m2a), respectively. The calculated maximum temperature gradient of gas hydrate formation is 0.058 鈩，

本文编号：2060771