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从勘探技术和资源评价的角度综述了甲烷水合物生成和聚集的重要特征 ,如地震反射剖面、测井曲线资料、地球化学特点等以及对未知区的地质勘探和选区评价。甲烷水合物在地震剖面上主要表现为BSR(似海底反射 )、振幅变形 (空白反射 )、速度倒置、速度—振幅结构 ( VAMPS)等 ,大规模的甲烷水合物聚集可以通过高电阻率 ( >1 0 0欧姆·米 )声波速度、低体积密度等号数进行直接判读。此项研究实例表明 ,沉积物中典型甲烷水合物具有低渗透性和高毛细管孔隙压力特点 ,地层孔隙水矿化度也呈异常值 ,并具有各自独特的地质特征。现场计算巨型甲烷水合物储层中甲烷资源量的方法可分为 :测井资料计算法公式为 :SW=( ab Rw/m· Rt) 1/ n;地震资料计算法公式为 :ρp=( 1 - ) ρm+ ( 1 - s) ρw+ sρh、VH=λ··S。对全球甲烷水合物总资源量预测的统计达 2 0× 1 0 15m3 以上。甲烷水合物形成需满足高压、低温条件 ,要求海水深度 >30 0 m。因此 ,甲烷水合物的分布严格地局限于两极地区和陆坡以下的深水地区 ,并具有 3种聚集类型 :1 .永久性冻土带 ;2 .浅水环境 ;3.深水环境。深海钻探计划 ( DSDP)和大洋钻探计划 ( ODP)已在下述 1 0个地区发现大规模的甲烷水合物聚集 ,他们是 :秘鲁、哥斯达黎加、危地马拉、?
The important features of methane hydrate formation and accumulation, such as seismic reflection profile, well logging data, geochemical characteristics and so on, as well as the geological prospecting and constituency evaluation of unknown areas are summarized from the aspects of exploration techniques and resource evaluation. Methane hydrate mainly shows as BSR (Seabed Reflectance), Amplitude Deformation (Blank Reflection), Inversion of Velocity, VAMPS, etc. on the seismic section. Large-scale methane hydrate accumulation can be achieved by high resistivity (> 1 0 0 ohm · m) sonic speed, low bulk density and other numbers for direct interpretation. The study shows that the typical methane hydrate in sediments is characterized by low permeability and high capillary pressure, and the pore water salinity is also abnormal and has its own unique geological features. Methods for calculating the amount of methane in a giant methane hydrate reservoir on site can be divided into: The calculation formula for logging data is: SW = (ab Rw / m · Rt) 1 / n; The formula for calculating seismic data is: ρp = (1 - ) ρm + (1 - s) ρw + sρh, VH = λ · · S. The total amount of methane hydrate resources in the world is predicted to be more than 2 × 10 15 m 3. Methane hydrate formation to meet the high pressure, low temperature conditions, requiring seawater depth> 30 0 m. Therefore, the distribution of methane hydrate is strictly confined to deep-water areas below the dipole and slope and has three types of accumulation: 1. Permafrost zone; 2. Shallow water environment; 3. Deep water environment. The Deep Sea Drilling Program (DSDP) and the Ocean Drilling Program (ODP) have found massive methane hydrate buildup in the following 10 regions: Peru, Costa Rica, Guatemala?