hello and welcome to geophysics made easy with Blueback reservoir and this episode we're going to look at colored inversion colored inversion is based on an approximation that sparse spike inversion can be modeled with a simple convolution process this process requires the seismic to be convolved with the wavelet whose amplitude converts the seismic spectrum to that of the Earth's acoustic impedance spectrum in our case that's from the well looks in order to complete this process we design an operator which will take the seismic spectrum and shape it so it best matches that of the wells this is done interactively by adjusting min and Max frequencies and frequency taper so this process works by first taking a average spectrum from the wells which represents the Earth's acoustic ambience then we create an average spectrum from the seismic and finally we design an operator which can translate between the two and convert the seismic into acoustic impedance and finally we use the operator on the seismic to create that volume let's just finally say ok color conversion what's in for me well called inversion is a very quick method of converting seismic to acoustic impedance we can use it to transform well reflectivities into pitch physical properties like vp vs and rho and there's a tool in the SSRC toolbox to do this we can also use it to create extended elastic impedance from intercept and gradient and extended elastic impedance is most frequently used to produce fluid and lithology cubes just just remember inversion is not a dirty word and can be a very easy process so let's have a look in portrayal how that works so what I'm going to do is first of all open up my blue back home and choose the tool firstly colored inversion operator design and if we have a look here the first step is to take the wells and get an average spectrum from the wells by using the acoustic impedance log and here we get the spectrum of the wells in green and a sort of best fit in blue we can also smooth the spectrum of the wells if we like maybe if we have a little bit of background noise by using more than one well so here's our spectrum from the wells which is representing the acoustic impedance of the earth it's a best fit based on the wells but we can also enter a manual number here if we if we like so 12 and 0.6 is more or less what I've got the next step is to create a average seismic spectrum from your seismic so here I'm going to choose my far stacks and I'm going to select a thousand random traces and recalculate and here I get my seismic averaged spectrum in blue with a smooth spectrum in red I can just the smoothing here and you see it's reflected so the next part is to take this seismic spectrum and apply an operator so that it best matches the wells and you see this transformation happened down in this bottom left hand plot we have the Welles spectrum in blue the size making red the operator is in green and I sort of convolved result is in yellow so as I adjust the smoothing here you see the convolution change and also if I increase the high and low frequency frequency cut-offs here so in this case it's probably better to adjust the high frequency to about 60 I get a nice nicer shape there and to take a little bit of care to find the smoothest smoothest result so by reducing the smoothing on the sides we can get a much nicer match here with that of the wells then simply just to give a name press apply and I now have in my input tree an operator I can double click on that and see the settings for the operator but what that does is then let me input that into colored inversion so in here I can choose my new operator and I can take my for example my intercept and transform back to color inverted intercept AI I could then go one step further once I've color inverted both intercept and gradient and for example use the extended elastic impedance volume by importing both color and version intercept gradients and that will help me produce a seismic cube which can best highlight fluids so again thanks for listening and any questions please let us know