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What are the main petrological techniques for estimating the probability that an aquifer contains a high proportion of viable petroleum?

I'm not an expert, but the easiest way to detect hydrocarbons is using resistivity as pores filled with oil/gas will conduct electric current less easily than pores filled with formation water, which often has high salinity. In areas where formation water has low salinity and oils are impure (biodegraded for instance) this may cause a problem. But also, density neutron relationships can help identify pay-zones. More specialized tools like MRIL (http://www.halliburton.com/ps/default.a ... &navid=182) can help to add more detail and in complicated settings. What I understand is that the MRIL generates a quick magnetic burst and then registers the time it takes for the fluid in the pores to react to this new magnetic realigning. Oil being more viscous will have a slower reaction time.

I might be forgetting tools though

Oh, I just saw your post leading up to this question...

And you might want to know that these petrophysical properties are measured using WireLine Logging or Logging while drilling techniques. In Wireline logging a pipe with high tech measuring equipment is lowered in the drilled well, while with loggin while drilling this equipment follows the drill-bit during drilling. The later is being used more and more, because wells are often deviated and the wellsite geologist needs to now where the drill-bit is to help steer the drilling.

Jacob,

Thanks for your answer, that helps me put in perspective some of the things I learned in lectures recently. It is amazing how their different properties can be used to gradually differentiate between water and oil. Does anyone know how much work all this would take to complete?

Dear
There are General Workflow :
1- Determine The Temperature Gradient.
2- Determine the basic elements (Rmf - Rmc - Rm - Rw ) @ Formation temperature.
3- Environmental correction for tools (GR - Density - Neutron - Resistivity ).
4- Build Porosity model (Total Porosity - Primary Porosity - Secondary Porosity - Effective porosity).
5- Water saturation ( Archie - Simendoux - Indonesian - ......... etc).
6- Cut-offs Value Models
7- Final template and Final Table and Final report and recommended Perforated intervals .
Thanks

thanks, that sounds like a lot