页岩中矿物组分测定方法探讨

A Discussion on Measuring Methods of Shale Mineral Components

X-射线衍射(XRD)是测定页岩矿物组成的基本方法,其定量精度受到矿物种类、衍射能力、粒度和衍射峰重叠等多种因素影响。选择四川盆地黔浅1井页岩进行矿物组分测定,通过2种实验结果对比,找出提高页岩矿物组分定量精度的方法。方法1:全岩XRD直接测定与定量;方法2:经物相溶解、Stokes重力分离后,对不同粒级的矿物分别进行XRD测定与定量。结果显示,通过2种实验方法获得的碳酸盐类矿物的百分含量差别较大,反映了直接XRD定量方法在矿物组分含量测定中并不是完全可信的。经物相溶解及重力分离后进行XRD测试,可很大程度上提高测试精度,同时获得的页岩中矿物不同粒度的含量对认识页岩成岩过程及页岩性质较各单矿物含量更具有实际意义。

X-ray diffraction is a basic method for determination of shale mineral composition,quantitative accuracy by diffraction by mineral composition,particle size,the diffraction peaks overlap,and other factors.Choose well QQ1#drilling wells hole samples in Sichuan Basin shale mineral components determined,by comparison with two kinds of experimental results,find out the methods of improving the precision for quantitative shale mineral components.Method 1：Whole rock direct determination and quantitative XRD;Method 2：The phase after dissolving stokes gravity separation of different graded mineral XRD measurement and quantitative respectively.Results showed that through two experimental methods have a greater difference between the percentage of carbonate minerals,directly reflects the XRD quantitative methods in the content of mineral component is not fully trusted.The phase after dissolving and gravity separation XRD test can largely improve the test precision and shale in the mineral content of different granularity of shale diagenesis and shale properties than the single mineral content has more practical significance.