Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
ANALYTICAL TRANSIENT HEAT CONDUCTION IN 2-D POLAR COORDINATES IN A COMPOSITE CYLINDER DOMAIN APPLIED TO PLUG AND ABANDONMENT OF OIL WELLS
Submission Author:
Gabriel Saavedra , SP
Co-Authors:
Gabriel Saavedra, Marcelo De Lemos
Presenter: Gabriel Saavedra
doi://10.26678/ABCM.ENCIT2022.CIT22-0178
Abstract
Plug and Abandonment (P&A) procedure is a mandatory regulatory requirement when the economical capacity of the reservouir is depleted and need to be decommissioned, being a non-profitable and expensive activity. New technologies are being studied in order to shrink costs by doing P&A focusing on the minimization of maneuvers and rig operations to accomplish this operation. The thermite reaction approach is one of these emerging studies, consisting on an exotermic reaction capable of surpass the melting point of the oil well structure and, after the cooldown and solidification of the melted product, a seal is formed on the well cross-section accomplishing P&A requirements. An analytical mathematical framework based on the Separation Of Variables (SOV) is presented in this work in order to solve the transient heat conduction governing equation in 2-D polar coordinates in a solid composite , which eigenvalue problem in radial direction is implicitly dependent on the polar transverse eigenvalues where only real eigenvalues are computed, differently when considering the analysis on 2-D axisymmetric domain. Also, non-homogeneous boundary conditions on the radial direction of the first, second and third kind can be prescribed on the composite cylinder domain , whereas on the angular direction only homogeneous boundary condition of first and second kind should be considered. On the transient governing equation, the heat source term is spatial-dependent on the radial and angular directions and is time-independent, which can be arbitrated in any layer that constitutes the composite cylinder domain .The solution is computed taking into account thermophysical and geometrical specifications applied to real case oil wells and the heat source is determined by the stoichiometric mixture of the thermite reaction. Validation with numerical solution is presented in order to verify the mathematical framework correctness. Lastly, SOV approach can be applied to solid or hollow cyilinders composite media by performing minor modifications in the mathematical modeling.
Keywords
Transient Heat Conduction, Oil&Gas, Analytical Non-steady Heat Conduction, composite cylinder, Generalized Eigenvalues and Eigenvectors Problems, heat source, Composite Hollow Cylinder Medium
