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Comparison of geometrically linear and nonlinear poroplasticity for the borehole stability problemтезисы доклада
- Автор: Vershinin A.V.
- Сборник: ABSTRACT BOOK INTERNATIONAL CONFERENCE ON NONLINEAR SOLID MECHANICS ICoNSoM 2022
- Тезисы
- Год издания: 2022
- Первая страница: 178
- Последняя страница: 178
- Аннотация: It is widely known that the determination of technological parameters, for which the wellbore maintains its stability, and risk assessment during drilling are one of the most important problems in geomechanics of hydrocarbon fields. When drilling, in general, a bit and mud generates a pressure on the rock, thereby deforming it and redistributing the stresses (superposition of generally finite strains), causing the reaction of the rock on the applied impact. This may lead to the formation and development of localized zones of plastic shear bands. Different rock’s properties and their evolution during deformation should be taken into account to correctly simulate this process. In addition, the rock is usually prestressed, which is defined by the components of the generally anisotropic initial stress tensor. Real rocks are characterized by the presence of pores and a fluid that saturates them and the possibility of nonlinear inelastic deformation with the accumulation of plastic deformations and their localizations leading to the corresponding variations of dynamic porosity and permeability. The paper presents mathematical models and numerical algorithms that can be used to solve the problems of a wellbore stability in a poroelastoplastic formulation under small and finite strains. A generalization of the classical Biot’s model to the poroelastoplastic medium is considered in order to simulate a shear banding phenomena taking place around the borehole drilled in the prestressed solid leading to the change in the pore pressure in the surrounding rock as well as a redistribution of stresses and accumulated plastic strains. An isoparametric spectral element method is applied to discretize a geometric model and equations in space on curvilinear unstructured meshes of high order, which allows to precisely describe a curvilinear shape of the borehole on a relatively coarse mesh. CUDA technology is used to parallelize the implemented algorithm on the massively parallel graphics-processing unit. Several model examples of the borehole stability problem are presented and numerical results are analyzed. The research for this article was performed in Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences and was financially supported by Russian Science Foundation (project No. 19- 77-10062) in the part related to the development of mathematical models and numerical modeling and was performed in Lomonosov Moscow State University and was supported by the grant of the President of the Russian Federation for young scientists - doctors of sciences MD-208.2021.1.1 in the part related to the development of numerical algorithms for problem solving and their parallel implementation on massively parallel high performance computing systems.
- Добавил в систему: Вершинин Анатолий Викторович