In the upstream oild and gas industry, 3D earth models are crucial for decision making and other purposes. They help for example to check the consistency between geological objects, to plan the path of non-vertical wells, and to monitor the reservoir (4D seismic). It is rare at present that a full suite of technologies from seismic to reservoir flow simulation is applied in a single study. Each new seismic survey or well may invalidate partially or completely the 3d earth model. Editing and updating a 3D earth model via a rapid and fully interactive approach is needed more than ever. The "black box" approach is no longer sufficient. After an inventory and an analysis of the editing operations, we are able to split them into elementary components (the methodology and the corresponding algorithms) and how to combine them to edit 3D Earth Model.