ScANNING ELECTRON MICROSCOPE

SEM Description:

SEM image C shows an enlargement of the red rectangle in image B, where many of the pore walls are bridged by illite fibers. The yellow arrows in image B & D point to a glob of bitumen (dead oil). The EDX spectrum obtained from this bitumen reveals a high percentage of carbon (75%), and a significant amount of sulfur (4.9%), and 3.10% iron as components of the bitumen. A blue arrow in image D points to a tiny ferroan dolomite rhomb. Image E shows the detail of illite fiber as seen in the green rectangular area in image C. Image F shows long whiskers of illite. In the EDX spectrum taken from these illite fibers, a high relative percentages of potassium (9.546%), significant amount of chlorine (1.828%), and  sodium (1.076%) are notable. The water-wet illite fibers, as seen in image C & E, can create an electrically conductive network throughout this sandstone, resulting in a significant reduction in the resistivity log responses in this obviously oil productive zone (based on the production data).