用井壁取心器取出的岩样一般仅作肉眼观察研究,以鉴定岩性和查明岩石中的油迹或是沥青,很少作苯或石油醚抽提。应用最简单的肉眼观察法往往不能肯切确定岩石的含油性,饱含流动性高的轻质原油的高渗透性储油层,在泥浆水强烈冲洗的条件下往往被评价为含水层,而相反地却把含有残余氧化石油的含水岩层评价为含油层。 Rock samples removed from wellbores are typically only examined macroscopically to identify lithology and to identify oil traces or bitumen in the rock, with little benzene or petroleum ether extraction. The simplest macroscopic method often fails to determine the oiliness of rocks. Highly permeable reservoirs with high mobility crude oil are often evaluated as aquifers under conditions of intense flushing of muddy water. Conversely However, the water-bearing formations containing residual oxidized petroleum were evaluated as oil-bearing formations.