I believe the name really refers to “sweet spot” with strong amplitude and low frequency. Sweetness attribute is quite useful especially for detecting sand bodies, even thin beds, within a shale sequence on your 3D seismic data. It may not of course work if the acoustic impedance contrast is not prominent between sand and shale or those two lithologies are highly interbedded. In this regard, sweetness attribute could be a very powerful piece of data in exploring gas charged sandstones. You may find numerous publications about this attribute.

It is simply derived by dividing reflection strength by the square root of instantaneous frequency. And you are right, “sweetness” is not one of the Rock Solid Attributes (RSA). But you can calculate it as user defined attribute under the Trace Calculator in version 8.8 and earlier. There is also good news; it is included as pre-defined function in IHS Kingdom 2015 release.

Let’s follow the below steps for user-defined option:
– Tools> Trace Calculations> Trace Calculator
– Choose 3D seismic data (amplitude) and assign it to a “letter” on the right (Let’s call it “A”)
– Enter the below formula on the formula line by using the built-in functions from the pull-down menu:

Envelope(A)/Sqrt(ClipByVal(Frequency(A),1,125))

(Warning: if you take the square-root of the frequency, the values may be on the extreme range, close to zero, etc. Therefore, the result should be clipped to a more meaningful range (i.e. nyquist frequency). 1 and 125 are the minimum and maximum values in the formula to keep the frequencies within the range of the actual data, but you can play with those numbers if you need)

– Store the formula for later use
– Select the 3D survey for the output as subset
– Also enter “sweetness” as new data type
– Then compute

Nice comments. I have done it using Trace Envelope for the reflection strength and Dominant frequency. Good results, but as stated before, need to have good AI contrast..

I believe the name really refers to “sweet spot” with strong amplitude and low frequency. Sweetness attribute is quite useful especially for detecting sand bodies, even thin beds, within a shale sequence on your 3D seismic data. It may not of course work if the acoustic impedance contrast is not prominent between sand and shale or those two lithologies are highly interbedded. In this regard, sweetness attribute could be a very powerful piece of data in exploring gas charged sandstones. You may find numerous publications about this attribute.

It is simply derived by dividing reflection strength by the square root of instantaneous frequency. And you are right, “sweetness” is not one of the Rock Solid Attributes (RSA). But you can calculate it as user defined attribute under the Trace Calculator in version 8.8 and earlier. There is also good news; it is included as pre-defined function in IHS Kingdom 2015 release.

Let’s follow the below steps for user-defined option:

– Tools> Trace Calculations> Trace Calculator

– Choose 3D seismic data (amplitude) and assign it to a “letter” on the right (Let’s call it “A”)

– Enter the below formula on the formula line by using the built-in functions from the pull-down menu:

Envelope(A)/Sqrt(ClipByVal(Frequency(A),1,125))

(Warning: if you take the square-root of the frequency, the values may be on the extreme range, close to zero, etc. Therefore, the result should be clipped to a more meaningful range (i.e. nyquist frequency). 1 and 125 are the minimum and maximum values in the formula to keep the frequencies within the range of the actual data, but you can play with those numbers if you need)

– Store the formula for later use

– Select the 3D survey for the output as subset

– Also enter “sweetness” as new data type

– Then compute

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LikeIn the above formula, the ‘ClipbyVal’ function needs to be changed to ‘ClipByVal’ due to a syntax error

Thanks Scott!

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LikeNice comments. I have done it using Trace Envelope for the reflection strength and Dominant frequency. Good results, but as stated before, need to have good AI contrast..

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