静力触探在水合物勘探中的应用

APPLICATION PROSPECT OF CPT IN GAS HYDRATE EXPLORATION

水合物的勘探方法主要有地球物理方法、地球化学方法、微生物方法和地质学方法等,三维地震为主要而且也是最重要的手段。含有游离天然气和天然气水合物的海底沉积物在物理性质上存在明显差异,三维地震利用这些差异性可以确定天然气水合物的分布,但有些沉积物如碳酸盐岩也可以表现出类似的异常。对于精确确定海底沉积物物性及沉积物类型,静力触探具有非常突出的优势。静力触探可以开展土力学测试、土体摄像、定点地质取样、波速测试、热力学测试、磁力观测、电导率测试、放射性同位素测试和化学分析测试等,调查范围非常广泛。用CPT配合其他方法来联合勘探水合物是精确计算水合物分布及储量的非常有前景的方法。

Geophysical,geochemical,microbial and geological methods are widely used in gas hydrate exploration and 3 Dseismic method is doubtlessly the main and most important one.There are obvious differences in physical properties of sediments containing free natural gas and gas hydrates.The distribution of gas hydrates can be recognized by using these differences with 3 Dseismic data.However,some sediments,such as carbonate rocks may produce similar anomalies.CPT has prominent advantages in accurately determining the physical properties and types of sediments.It has the capability to carry out tasks such as soil mechanics testing,soil photography taking,geological sampling,P-S logging,thermodynamic testing,magnetic observation,conductivity testing,radioisotope testing and chemical analysis testing,etc.Combined with other methods,CPT is believed a very promising method for accurately determinating hydrate distribution and calculating gas reserves in gas hydrate exploration.