摘要
以往研究表明冻土层及断层是陆域冻土区天然气水合物重要成藏要素,为了研究木里天然气水合物地区的断层及冻土层分布情况和天然气水合物成藏条件,应用音频大地电磁测深对木里试验区进行了冻土层及断层构造调查。依据试验区电性结构划分出了5组断层和4个断层构造发育区,其中F_3断层发育规模最大。试验区冻土层发育不均匀,平面以岛状特征分布,平均厚度超过60 m,划分了3个冻土层发育区。分析了天然气水合物成藏与冻土层、断层构造之间的关系,结合冻土层及断层构造条件,试验区东部F_(3-3)至F_(3-5)及F_4断层附近为天然气水合物成藏有利区。
Previous studies show that frozen soil and fault are important reservoir-forming factors of natural gas hydrate in land-based frozen area.In order to study the fault and frozen soil distribution situations of natural gas hydrate in Muli area,the authors investigated distribution characteristics of frozen soil layer and fault structures of the study area through electromagnetic test.Based on electrical characteristics of resistivity profile of the test area in combination with geological setting,the authors recognized five groups of fault layers in the study area,with four of them possessing the biggest development scale.Frozen soil layer development area within the study area can be divided into 3 sub-areas,and fault layer structure development area can be divided into 4 sub-areas.The authors also analyzed the relationship between natural gas hydrate reservoir-forming condition,frozen soil layer and fault layer structures.By combination of frozen soil layer with area of developed fault layer structure,the authors infer that the east part from F_(3-3) to F_(3-5) and the place near F_4 fault layer are natural gas hydrate reservoir-forming favorable areas.
引文
[1]卢振权,翟刚毅,文怀军,等.青海木里三露天冻土区天然气水合物形成与分布地质控制因素[J].现代地质,2015,29(5):1002-1013.
[2]翟刚毅,卢振权,卢海龙,等.祁连山冻土区天然气水合物成矿系统[J].矿物岩石,2014,34(4):79-92.
[3]卢振权,李永红,王伟超,等.青海木里三露天冻土天然气水合物成藏模式研究[J].现代地质,2015,29(5):1014-1023.
[4]祝有海,张永勤,文怀军,等.祁连山冻土区天然气水合物及其基本特征[J].地球学报,2010,31(1):7-16.
[5]邵龙义,杨致宇,李永红,等.青海木里聚乎更天然气水合物潜在区中侏罗世岩相古地理特征[J].现代地质,2015,29(5):1061-1072.
[6]冯益民.祁连造山带研究概况——历史、现状及展望[J].地球科学进展,1997,12(4):5-12.
[7]冯益民,吴汉泉.北祁连山及其邻区古生代以来的大地构造演化初探[J].西北地质科学,1992,13(2):61-73.
[8]符俊辉,周立发.南祁连盆地三叠纪地层及石油地质特征[J].西北地质科学,2000,21(2):64-72.
[9]文怀军,邵龙义,李永红,等.青海省天峻县木里煤田聚乎更矿区构造轮廓和地层格架[J].地质通报,2011,30(12):1823-1828.
[10]文怀军,鲁静,尚潞君,等.青海聚乎更矿区侏罗纪含煤岩系层序地层研究[J].中国煤田地质,2006,18(5):19-21.
[11]孙军飞,孙红波,张发德,等.青海木里煤田构造分带性特点及赋煤规律[J].中国煤炭地质,2009,21(8):9-11.
[12]卢振权,祝有海,张永勤,等.青海省祁连山冻土区天然气水合物基本地质特征[J].矿床地质,2010,29(1):182-191.
[13]裴发根,方慧,杜炳锐,等.AMT正演模拟及反演求导方法在探测冻土厚度中的应用——以青海木里地区多年冻土层为例[J].物探与化探,2016,40(2):405-410.
[14]许志琴,曾令森,杨经绥,等.走滑断裂、“挤压性盆—山构造”与油气资源关系的探讨[J].地球科学,2004,29(6):631-643.