Re: How to tie well top and depth map in Petrel
I think your friend is right about getting residual maps. I am not sure how to do it in Petrel but with CPS3, depending on the number of wells, so take each well top from each and every well as a control point then use contouring algorithm to get a map. Get a residual map, now u can shift your horizon map up or down to match your markers.
The pitfall of this method is if your interpreted surfaces are highly structured, i.e. big faults, big synclines and anticlines.