On the influence of axial loads in well casing integrity
Well casing; Well integrity; Axial stress; Finite element method.
The objective of this work is to evaluate the influence of the action of effects that cause axial stresses on the integrity verification calculations of casing tubulars. This assessment is relevant because, in well projects, some scenarios subjected to combined loads are capable of penalizing the resistance to collapse, which may cause an unexpected failure in the casing. Due to the complexity of the problem, numerical simulations supported by the finite element method are used to reproduce the evaluated scenarios. To achieve the proposed objective, the development methodology of this work is based on four main steps: i) study and determination of the scenarios that the casing tubes must be submitted; ii) determination of loads, including studies of effects and phenomena that act on the casing; iii) identification of the most appropriate numerical modeling for the reproduction of scenarios considering the integrally modeled casing tubes and the various possibilities of combined loads that act in these tubes; and iv) performing numerical analyzes contemplating the various scenarios considered and evaluating critical situations that may produce failure in the integrity of the casing. At the end of the work, the coating structure has been fully analyzed from the axial stress fields and resulting pressure forces obtained in the numerical simulations, finding the most critical sections in relation to loading and resistance and evaluating the integrity of the coating more effectively.