Estimating Hydrocarbon Volumes in Oil and Gas Fields

[@samcrosswords8979]

Thank you so much!
Cleaer and to the point 👍

[@mazenomar7279]

I have two quiz.the first sone company use total porosity instead of effecive one.do you suggest why .the second one what is the basis for choosing montecarlo distribution input curve.❤❤

[@AlanFoumGeophysicist]

Effective porosity is the porosity that is connected, Total porosity includes non connected pores. The non connected pores cannot contain hydrocarbons. The connected pores may contain producible hydrocarbons and therefore this is what should be used in HC in place estimation. The two porosity estimates are usually very close in most rocks
- please see my video a basic primer on porosity and permeability

[@shadabkhan-yh6li]

While calculating the economics, should we use the minimum GIIP numbers or mean GIIP number??

[@AlanFoumGeophysicist]

I talk about this in my Basic economics primer video
To sum up we should use recoverable resource estimates not Volume in place
We should really use 3 cases , low. mid and high: weighted using Swanson's rule - with 30% weighting to low and high and 40% weighting to the mid case to come up with a summary NPV value
If we are to use one case only (not ideal) then we should use the mean case as this represents an average of all the cases

[@shadabkhan-yh6li]

@@AlanFoumGeophysicist ok thank you. i appreciate your swift response