Wet clay and dry clay

[mid]

Hi All,

How to determine wet clay density and resistivity normally, also dry clay denstiy and resistivity to use them as an input in IP clay model, then how to differentiate between wet clay and dry clay for a certain well

Can someone help

Thanks

[petrophysicist]

The dry clay input parameters are determined automatically the software while you have to put the Wet clay parameters by using crossplots.

[anjumbukhari]

how to use those crossplots dear

[Euskadi59]

Guys, dry clay inputs is one of the most importat values when you use Dual waters equations( or similars), wet clays are easy (or not on DEN-CN xplots) but you must have an idea about dry clays ( default values of 2.78 on IP are focused on gulf sediments and still they are generally very high., for this values most of clays should be chlorite or other weight clays). Try to determine those values on core data withouth so high temperature of treatment and with controled humity ( no more than 85 Centigrades), it take more time and is more expensive, but if you expose your core data to more than that, it is posible you 'never know if it is total phi, effective or a mix value, the you for sure have been lost you money on this try. Another tiem expensing method is try to compare DW and Juhazs SW, the last use insted a RWbound value a comparison between dry and wet clay, if you have any data of RWbound ( not ever related to 1/phishale**2 relatioships) you should obtain on both formulae similar values. Regards and let me know yous experiences
MM (Euskadi 59)... Also constrains your values with less acuratte formulaes as Simandoux

[Euskadi59]

Guys I take adventage of your IP provider, but take care, not always default values are right, I saw people use DW with the default values of .1 at 60 F, it is for sure wrong, RWbound should be on 15 to 20% of RW, anyway take care exceptions are wide spread. Enjoit and let me know when last ip (4.6) where available
Regards and never use default values, take a time to see what it does meanth
MM(Euskadi59)

[pggeology]

Dear Folks,
I get trouble with input parameters,please tell me how I can use crossplot in order to determine Density, neutron, Rt and Rxo of wetclay

[edisonnadeak]

Dear Folks,
I get trouble with input parameters,please tell me how I can use cross-plot in order to determine Density, neutron, Rt and Rxo of wet clay

Good morning all,

Please introduce me, my name edison, i am a junior well log analyst.

Maybe I can give suggestion for the question above.

In my experience, the wet clay point could be determine in your zone ( if you found a thick shale interval) using x-plot RHOB-NPHI-GR.

Find (helped by histogram of GR to determine your most shale point) the RHOBCL and PHINCL point as wet clay point.

Dry clay point should be determine by laboratory worked.

For resistivity we could read at the same depth at our shale/clay point.

For case you not have a thick shaley interval, then you could use from another near well, or interval that analog with your interval/zone from depositional environment as an approach.

That is a simple tips from me, maybe it isn't totally right.


regards,

Edn

[pggeology]

Thank you Edison so much. I do the same as your method but probably I define wrong shale point so it cause high water saturation. Could you guide me how I can get sand point and shale point in GR histogram. I could run it and chose All Gaussian Line distribution. Then I chose min and max line. Thank you again for your help.

Best Regards,
PGGeologist