Influence of well drilling modelling strategies on the mechanical behavior of salt rock

Resumo

This work compares two strategies of computational modelling based on finite element method applied

to vertical wells drilling, evaluating their influence on the mechanical behavior of salt rocks, using Abaqus com-
mercial software. Salt rocks properties favor the entrapment of gas and oil on underlying layers. On the other

hand, these rocks are subjected to the creep effect, which provoke the hole closure. In this context, predictions are
essential to reduce operational risks related to entrapment of drilling column and casing collapses. Currently, as a
simplified approach, it is common to consider the drilling process to be performed instantaneously, at the beginning
of a numerical analysis, disregarding the rate of penetration (ROP). In this way, there may be an overestimation
of the well closure depending on the studied scenario. In this context, this work proposes a strategy considering

the ROP in order to perform the salt rock excavation along time and compares the obtained results with the sim-
plified strategy behavior. In this regard, the main contribution of this work is to evaluate the effect of two classical

strategies on the mechanical behavior of salt rocks during well drilling.