This paper is the second part of a work that deals with the role of reservoir geomechanics in the assessment of the well's casing behavior. A case of study is presented in order to illustrate the numerical strategy developed to evaluate the fluid-mechanical behavior of reservoir and the resulting response of the well from generated geomechanical effects in the field. The built global model was based on Namorado Field (Campos Basin, Brazil), and was simulated considering a robust fluid-mechanical coupling methodology, presented in the first paper. A horizontal well was locally modeled, and it was simulated employing the submodeling technique. Results showed the importance of employing a rigorous fluid-mechanical methodology in well integrity analysis, once the stress states in the well region were fairly affected by the accounting of geomechanical effects, reflecting on the casing yielding onset.

1. Introduction

The wells are linear constructions whose geomechanical behavior is closely related to the stress state of the rock which is going through, to the fluid employed during drilling, to the drilling direction and to the casing type. By the activities performed through the well, the reservoir undergoes significant changes in its equilibrium configuration, once the production (or injection) of fluid in the porous medium causes significant variations in their pore pressure and therefore in its stress state. During the lifetime of an oil field, well integrity should be taken into account under the geomechanical perspective. This work aims to show the influence of geomechanical effects over the integrity of an oil well, employing partially coupled fluid-mechanical simulations and the finite element submodeling technique. The theoretical framework of the techniques employed in this application can be found in the first part of this work [1]. The numerical model adopted in this study was based on Namorado Field (Campos Basin, Brazil), and an inclined well was chosen to perform the local analysis. Since the geomechanical effects were obtained in the reservoir scale, special procedures had to be followed in order to obtain the stress field at the well scale [2]. The submodeling technique was used to analyze the casing response under the effects observed in the global simulation.

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