title: Gas initially in place
text: # Gas initially in place
  
  Gas initially in place (GIIP) or original gas in place (OGIP) denote the total estimated quantity (volume) of natural gas contained in a "subsurface" asset prior to extraction (production).
  
  Gas Initially In Place = Gross Rock Volume * Net/Gross * Porosity * average initial Gas Saturation / Formation Volume Factor
  
  