Creating saturation functions from well logs in Petrel

[vinomarky]

All - I received the below via pm today, and though the broader audience may benefit from the answer

"modeling Sw in petrel

please i need help
I want to model sw in petrel.
I wonder if it is possible to model with data from well logs.
I have read that the sw model makes it from contact with PC functions, but in my case I haven´t pc laboratory data.
I have just sw of well logs.

I hope your help Thanks.
I need a solution to solve.

thanks in advance "

First thing, is unless you really don't care about the accuracy, do not simply populate saturation from logs like any other property (ie SGS etc). Saturation is driven by pore throat size, height above free water level and wettability etc - that is... geology. You need to understand better the link between your saturation characteristics and your geology. Once you have done that you simply populate the rest of your model based upon your rock properties

How?

Simple way to start is by cross plot. Lets assume your log derived saturations are correct (often not the case). Lets also assume your log derived perms are correct (almost always not correct). Try crossplot of Sw (x axis) against Perm (y-axis, log scale), and colour code the points by height against FWL (create this property via property calculator) - do you see any relationship? What if you substitute perm for SQRT(Perm/Phi)? What if you repeat the above steps, but this time filtering on different facies?

Get the idea? You are embarking on a bit of detective work to try to find what is controlling saturation in your geology. Once you find this, you can populate the rest of the model the same way

Good luck

[paolomaldini]

thanks a lot.