Petrographic Scanning Electron Microscopy (SEM)

Supplementary to Thin Section Analysis, Scanning Electron Microscopy (SEM) is often necessary to determine reservoir sensitivity and will show:

Clay morphology and distribution
Porosity connectivity and pore throats
Presence / absence of porosity indicators
Presence / absence of effective porosity
Presence / absence of slot porosity
Screening for low, moderate and good reservoir quality sandstone
Potential for fines migration
Minerals present that indicate sensitivity to drilling and completion fluids

Clay minerals such as fine, fibrous illite, pore lining smectite or chlorite and migratable kaolinite are often not visible in thin section. SEM analysis clearly shows the relationship of these clay types to the pores and pore throats.

SEM Image of Illite clay — SEM Images of illite and kaolinite clay.

SEM Image of Kaolinite clay — SEM Images of illite and kaolinite clay.