WI (Wettability Index)
Jump to navigation
Jump to search
WI = wettability index.
Wettability index ranges from "+1" for extremely water-wet case to "-1" for extremely oil-wet rock, while “0” is for neutral wettability, when rock surface has no strong preference to the fluids present.
To measure the wettability index several tests are available, like Amott test, modified Amott test, USBM method, etc. When either the contact angle or the wettability index is known the second one can be calculated by using the cosine or cosine inverse, respectively.