基于生烃思路的微生物成因水合物资源量估算——以琼东南盆地西南深水区为例  

Estimation of microbial hydrate resources based on hydrocarbon generation material balance method:Case study of deep water area in southwestern Qiongdongnan Basin

作　　者：刘杰[1,2] 杨睿[3] 邬黛黛 金光荣[1] Liu Jie;Yang Rui;Wu Dai-dai;Jin Guang-rong(Key Laboratory of Gas Hydrate,Guangzhou Institute of Energy Conversion,Guangzhou 510640,China;Institulion of South China Sea Ecology and Environmental Engineering,Chinese Acdemy of Sciences,Guangzhou 511458,China;Qingdao Institute of Marine Geology Qingdao 266071,China)

机构地区：[1]中国科学院广州能源研究所,广东广州510640 [2]中国科学院南海生态环境工程创新研究院,广东广州511458 [3]青岛海洋地质研究所,山东青岛266071

出　　处：《天然气地球科学》2019年第4期539-548,共10页Natural Gas Geoscience

基　　金：中国科学院天然气水合物重点实验室基金(编号:Y807je1001;Y707jd1001);中国科学院南海生态环境工程创新研究院创新发展基金(编号:ISEE2018YB03);广州市珠江科技新星项目(编号:201710010198);广东省促进经济发展专项资金(海洋经济发展用途)(编号:GDME-2018D002)联合资助

摘　　要：琼东南盆地深水区的天然气水合物成藏条件优良,是天然气水合物资源有利的勘探远景区。综合底水温度、地热梯度、有机碳含量和沉积速率等资料,分析了该海域范围内天然气水合物稳定带厚度的分布特征,并采用基于运移—反应数值模拟得到的转换函数,对琼东南盆地西南深水区内天然气水合物资源量进行了初步估算。结果表明:生物成因甲烷水合物分布在水深大于600m左右的海底,稳定带最大厚度约300m;微生物成因水合物所蕴含甲烷量达5.7×10^(12) m^3,其中自生自储扩散型天然气水合物远景总量约0.7×10^(12) m^3甲烷气;下生上储渗漏型水合物天然气水合物远景总量约5×10^(12) m^3甲烷气。后者约为原位微生物甲烷水合物资源量的7倍。由此可见,研究区微生物成因天然气水合物的烃类气体以深部运移烃类的供应为主;高效的流体运移通道是控制该区水合物藏富集的重要因素。基于生烃思路的资源量估算方法与通过体积法计算的天然气水合物资源量的数量级(×10^(12) m^3)一致,显示了该方法的有效性。The excellent reservoir forming condition indicates it is a favorable exploration prospect for gas hydrate resources in the deep water area of Qiongdongnan Basin.Based on the data of bottom water temperature ,geothermal gradient, organic carbon content and deposition rate, the distribution characteristics of thickness of gas hydrate stable zone are analyzed in the study area.The gas hydrate resources are preliminarily estimated by using the parameterized transfer function obtained from the numerical simulation.The results show that biogenic methane hydrates are distributed in the seabed with a depth of more than 600 m, and the maximum thickness of the stable zone is about 300m.The total abundance of methane hydrate is estimated to be 5.7 × 10^12 m^3 in the study area. Among them, the prospective total amount of self-sourced diffusion biogenic gas hydrate is about 0.7 × 10^12 m^3 , and the total amount of gas hydrate by way of "lowergeneration and upper storage" is about 5 × 10^12 m^3 .The latter is about 7 times the amount of methane hydrate in situ. Therefore, the supply of hydrocarbon gas from microbial gas hydrates in the study area is dominated by deep hydrocarbon migration, and efficient fluid migration pathway is an important factor to control the accumulation of gas hydrate reservoirs in the study area.The resource estimation method based on hydrocarbon generation idea is consistent with the order of magnitude of natural gas hydrate resource calculated by volume method, which shows the effectiveness of this method.

关 键 词：天然气水合物 稳定带厚度 转换函数 资源量 琼东南盆地 

分 类 号：TE132.1[石油与天然气工程—油气勘探]