  The construction of 3D geological models is an essential task in oil/gas
exploration, development and production. However, it is a cumbersome,
time-consuming and error-prone task mainly because of the model's geometric and
topological complexity. The models construction is usually separated into
interpretation and 3D modeling, performed by different highly specialized
individuals, which leads to inconsistencies and intensifies the challenges. In
addition, the creation of models following geological rules is paramount for
properly depicting static and dynamic properties of oil/gas reservoirs. In this
work, we propose a sketch-based approach to expedite the creation of valid 3D
geological models by mimicking how domain experts interpret geological
structures, allowing creating models directly from interpretation sketches. Our
sketch-based modeler (Geo-Sketcher) is based on sketches of standard 2D
topographic and geological maps, comprised of lines, symbols and annotations.
We developed a graph-based representation to enable (1) the automatic
computation of the relative ages of rock series and layers, and (2) the
embedding of specific geological rules directly in the sketching. We introduce
the use of Hermite-Birkhoff Radial Basis Functions to interpolate the
geological map constraints, and demonstrate the capabilities of our approach
with a variety of results with different levels of complexity.
