*Surface Drilling Data for Constrained Hydraulic Fracturing and Fast Reservoir Simulation… DOI: http://dx.doi.org/10.5772/intechopen.84759*

interface properties on the fracture propagation initiation, growth and path. These tools include the Coulomb frictional contact and imperfect interface models. In the Coulomb frictional contact model, the contact between materials is modeled by setting the tangential traction S proportional to the normal force N at the interface by using the friction coefficient μ, i.e. **S** = min (μ **N, Sstick**), where **Sstick** is tangential traction required for the interfaces to stick with zero discontinuity. In other words, the materials stick until the tangential forces required by sticking exceeds the frictional term after which the interface is modeled by frictional sliding.

In the imperfect interface model, interfaces are represented implicitly by their overall phenomenological effects described with a much smaller number of interfacial parameters [26]. In this context of imperfect interface model, surface drilling derived logs provide once more the information needed to detect major interfaces that could be responsible for loss of energy during hydraulic fracturing. These major interfaces could be inferred from the resulting Young's Modulus or/and Poisson's ratio computed from the surface drilling data and the CMSE. For example, **Figure 2C**  shows an example of a Poisson's ratio pseudo-log estimated from surface drilling data where multiple spikes of high values indicate changes of lithology occurring where the well crosses a geologic interface. To illustrate the impact of interfaces and natural fractures on the fracture height, we will consider a 2D and a 3D case.
