油气储层钾氩定年中的自生粘土矿物提纯技术及意义

EXTRACTION METHOD AND SIGNIFICANCE OF AUTHIGENIC CLAY MINERALS IN SEDIMENTARY ROCKS FOR K-Ar AGE DATING

黄宝玲 王大锐 刘玉琳 苗国均

HUANG Bao-ling WANG Da-rui LIU Yu-lin MIAO Guo-jun

北京大学 地质系 北京 100083 2. 中国石油 勘探开发研究院, 北京 100871

Department of Geology, Beijing University, Beijing 100871, China 2. Research Institute of Petroleum Exploration & Development, CNPC, Beijing 100083, China

该实验尝试了一种从沉积岩中分离提纯自生粘土矿物的方法:反复冷冻-解冻法。其改进之处在于利用渗透于岩石样品中的水,在冷冻的情况下体积膨胀,而使岩石颗粒自然散开。实验的大部分岩样用改进的岩样碎样法分离出的粘土矿物,经扫描电镜及X-射线衍射分析鉴定证实,在<1μm粒级时,粘土组分中不含有碎屑的钾长石,而常规法无法达到这一点。另外,随着分离粒级的减小,粘土组分中碎屑伊利石的含量逐渐减少,在<0.2μm时,大部分组分中碎屑伊利石的含量<5%,有的已不含碎屑伊利石。

A new method was used to separate authigenic clay minerals in sedimentary rocks-a repetitive free zing thawing process.The aim of this process was to disaggregate rock samples using the volume expansion of water that impregnates samples.The new method can avoid the shortcoming that a conventional crushing produces an over crushing of the larger grains of a rock,creating artificially clay sized particles which become intimately mixed with the natural clay component of the rock.For the most of our samples,fractions smaller than 1μm,the new method already remove the presence of K feldspar,while the conventional method can not achieve;In addition,with the reduction of grain size,the content of detritus illite in clay mineral component decreased gradually.For our samples,in the most of fractions smaller than 0.2μm,the content of detritus illite 5%,in some of them,the detritus illite already removed.

中国石油天然气集团公司油气地球化学重点实验室资助项目(2000年度).

https://doi.org/10.11781/sysydz200206550