Author Description

Borehole breakouts have been used as an indicator of in-situ stress orientation for a long time. However because the borehole breakout initiation and propagation are the result of a series of complex processes that simultaneously affect the borehole wall, an explicit quantitative relationship between breakout geometry and in-situ stresses does not exist. The computational model of artificial neural network (ANN) is based on mathematics and algorithms, which make it possible to build the relationship between the shape of borehole breakouts and in-situ stresses. The goal of this research is to build the relationship between in-situ stresses and the shape of borehole breakouts, by which to obtain the corresponding in-situ stresses for different borehole breakout shapes. Because borehole breakout initiation and propagation are the result of a series of complex processes, once the initial zone of rock on the borehole wall is broken out, the stress conditions will change, and the newly exposed rock will be subjected to new stress conditions and a new breakout zone will emerge, so the stresses cannot be calculated analytically. Therefore, building a comprehensive finite element model to monitor process of borehole breakouts is necessary. In this research, Finite Element Modeling is carried out to monitor the borehole breakouts considering elasticity, poroelasticity, thermoporoelasticity and poroelastoplasticity.