WLD CAD – is software for well logging data processing. The program is based on the ANALYTICS technology and allows calculating result data by any (nonstandard) formula. It works like ‘analytical calculator’ but input data is not real numbers, it is logging channels. The program has unique ‘Drag-Drop-Action’ interface that allows making all actions by mouse. Data can be easily created, copied, moved, displayed and so on. The system supports tens predefined functions and many operators for well logging data. Using these functions and operators allows building very complicated formulae for data processing. WLD CAD program can be effectively used for the following purposes: 1. Fast testing formulae and algorithms for developing new well logging devices on the design stage (without programming and writing complicated code). 2. Fast testing formulae for new well logging data processing algorithms before code them and include in some software (for well logging data processing software developers). 3. Processing data with nonstandard algorithms that are not provided by common well logging processing software but can be presented by some mathematical formula (for geophysicists and well logging data interpreters).