Recently, artificial neural networks ANNs have been introduced to solve petroleum geomechanics characterisation problems dealing with the inherent nonlinear relationship in well log data. This paper presents a computational intelligence algorithm of artificial neural network ANN and genetic algorithm GA, which is studied and applied in petroleum geomechanics to estimate the information of earth stresses and fracture properties based on wellbore displacement information when drilling well. In this computational intelligence algorithm, an ANN is used to represent the nonlinear relationship between the petroleum geomechanics parameters and the wellbore deformation. GA is used to identify the set of unknown earth stresses and natural fracture properties at wellbore scale in a large space based on the objective function. Our experiments illustrate that the proposed computational intelligence method is able to generate reliable results.
['Shike Zhang', 'Xiaoqi Niu', 'Shunde Yin', 'Zhongliang Ru']
Estimation of earth stresses and fracture properties using numerical method and soft computing