Depth-shifting programs are commonly of two types: (a) automatic depth-shifting programs in which mathematical correlations are made among curves from different tool strings and the shifting is accomplished without user input, or (b) visual correlation programs in which the curves to be shifted are laid beside or on top of the base curve, allowing the user to instruct the program by noting correlative points on each log and calculating the depth offset. With older programs, the correlations can be made by using log prints and the shifts input to the screen or a file. Most programs allow the user to carry or cause the same shift to be performed on other curves recorded on the same tool. | Depth-shifting programs are commonly of two types: (a) automatic depth-shifting programs in which mathematical correlations are made among curves from different tool strings and the shifting is accomplished without user input, or (b) visual correlation programs in which the curves to be shifted are laid beside or on top of the base curve, allowing the user to instruct the program by noting correlative points on each log and calculating the depth offset. With older programs, the correlations can be made by using log prints and the shifts input to the screen or a file. Most programs allow the user to carry or cause the same shift to be performed on other curves recorded on the same tool. |