Application of unlimited and limited anisotropic core compression results for wellbore stability calculations

• Published in: IOP conference series. Materials Science and Engineering 2020-05, Vol.860 (1), p.12031
• Main Authors: Aliev, M M, Shafieva, S V, Karimova, N G, Gilyazova, S R
• Format: Article
• Language: English
• Subjects: Anisotropy; Compression tests; Coring; Elastic anisotropy; Elastic properties; Mathematical analysis; Modulus of elasticity; Multilayers; Poisson's ratio; Rocks; Stability; Stress concentration; Stress distribution; Tensors
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/860/1/012031

The study touches upon the issue of wellbore stability in wells drilled in anisotropic rocks. Initial data for solving this task is the results of anisotropic core samples testing for unlimited and limited compression taken from one section of the whole core and drilled in different directions. These data are taken from the works of foreign authors that are collected and presented in [1]. The problem of wellbore stability drilled in multi-layer highly anisotropic rocks is solved by applying a strength criterion that includes stress tensor components and the angle between the normal line to the slip area and the direction of lamination. Given that the values of the elastic modulus and Poisson's ratio for the anisotropic rocks under consideration in the main directions of anisotropy differ insignificantly, the stress distribution around the wellbore is accepted without taking into account the anisotropy of the elastic properties. It is believed that strength anisotropy is the cause of rock destruction. Thus, the components of the stress tensor are determined using the superposition method by summing the solutions of the classical Kirsch and Lame problems.