University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 47 1 2013 06 01 A 3D elasto-plastic FEM program developed for reservoir Geomechanics simulations: Introduction and case studies 81 90 50092 10.22059/ijmge.2013.50092 EN Amin Chamani Department of Petroleum Engineering, Curtin University, ARRC Building, 26 Dick Perry Avenue, Kensington, WA, 6151, Australia. 0000-0001-6977-5427 Vamegh Rasouli Department of Petroleum Engineering, Curtin University, ARRC Building, 26 Dick Perry Avenue, Kensington, WA, 6151, Australia. Journal Article 2013 04 19 The development of yielded or failure zone due to an engineering construction is a subject of study in different disciplines. In Petroleum engineering, depletion from and injection of gas into a porous rock can cause development of a yield zone around the reservoir. Studying this phenomenon requires elasto-plastic analysis of geomaterial, in this case the porous rocks. In this study, which is a continuation of a previous study investigating the elastic behaviour of geomaterial, the elasto-plastic responses of geomaterial were studied. A 3D finite element code (FEM) was developed, which can consider different constitutive models. The code features were explained and some case studies were presented to validate the output results of the code. The numerical model was, then, applied to study the development of the plastic zone around a horizontal porous formation subjected to the injection of gas. The model is described in detail and the results are presented. It was observed that by reducing the cohesion of rocks the extension of the plastic zone increased. Comparing to the elastic model, the ability to estimate the extension of the yield and failure zone is the main advantage of an elasto-plastic model. https://ijmge.ut.ac.ir/article_50092_da0798d326f592be5ce4301e37b92173.pdf