The present article proposes a method to significantly improve the construction and updating of 3D geological models used for oil and gas exploration. The proposed method takes advantage of the specific structures which characterize geological objects. We present a prototype of a “geological pilot” which enables monitoring the automatic building of a 3D model topologically and geologically consistent, starting from a set of unsegmented surfaces. The geological pilot uses a “Geological Evolution Scheme” (GES) which records all the interpretation elements that the exploration geologist, who is the end user, wishes to introduce into the model. The model building is performed by reading instructions deduced from the GES. Topology is dealt with step by step by using a “3D Generalized Maps” (3-G-Maps) data model enriched to enable the manipulation of objects having specific geological attributes. The result is a correct 3D model on which geological links between objects can easily be visualized. This model can automatically be revised in case of changes in the geometric data or in the interpretation. In its final version, the created modular tool will be plugged in 3D modelers currently used in exploration geology in order to improve their performance.