摘要
中国南海是西太平洋最大的边缘海之一 ,具备良好的天然气水合物成藏条件和勘探前景。根据沉积条件 (沉积速率、沉积相和含砂率等 )分析 ,综合多方面的地质条件 ,认为气水合物存在于水深30 0～ 35 0 0m的区域 ;陆坡和靠近沉积中心的高沉积速率的厚层沉积为天然气水合物聚集的有利部位 ,与BSR分布的吻合率在 6 0 %～ 80 %之间 ;等深流、重力流沉积和各类扇体 (如三角洲、扇三角洲、低位扇等 )的前缘为水合物沉积的有利相带 ,与BSR分布的吻合率在 5 0 %～ 75 %之间 ;赋存气水合物的沉积物的含砂率通常在 35 %～ 70 %之间。依据多方面资料的研究 ,在南海海域划分出 1 1个有利的天然气水合物勘探远景区块 ,面积共 1 2 .5 (± 1 .5 )× 1 0 4km2 ,约占整个南海总面积的 3.6 %。
South China Sea is a marginal sea in western Pacific Ocean, and has very good accumulation conditions and exploration prospect for natural gas hydrate. Based on the analysis of sedimentary conditions of natural gas hydrate and on the synthesis of multiple aspects of geological conditions, we obtained the following comprehensions. The natural gas hydrate occurs at the bottom of the seafloor where the water depth is between 300 m to 3 500 m; the natural gas hydrate is usually borne in the sediments at the continental slope or the thick sediments near the depositional center, where the depositional rate is very high;the contourite,the turbidite,and the front of various kinds of delta and fans (such as alluvial fan,low stand fans and fan delta) are considered to be the favorable facies for the accumulation of gas hydrate.Gas hydrate bearing sediments generally have the sand content of 35% to 70%.There are 11 favorable blocks of exploration prospects for gas hydrate having been predicted in South China Sea,and the total area of these blocks is 12.5(±1.5)×10~4 km^2,about 3.6% of the whole area of South China Sea.
出处
《地学前缘》
EI
CAS
CSCD
2004年第1期311-315,共5页
Earth Science Frontiers
基金
国土资源部中国地质调查局国家专项 (SHW 0 10 0 1)
科学技术部重大国际合作项目 ( 2 0 0 2aa615 2 0 0 )
关键词
中国南海
天然气水合物
成藏条件
远景区块
South China Sea
natural gas hydrate
accumulation conditions
favorable blocks
