Production Index (Shale)
Production Index (Shale) : An indication of source rock potential measured by the conversion of kerogen into free hydrocarbons (PI, S1/(S1+S2)): For PI < 0.08, the source is immature, for PI of 0.08 to 0.5, the source is in the oil window, for PI > 0.5, the source is in the gas window