Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
A Computational Heat Transfer Model for Thermite Reaction in Offshore Well Plugging and Abandonment Operation
Submission Author:
Thiago Dias dos Santos , SP
Co-Authors:
Rodrigo Gustavo Dourado da Silva, Thiago Dias dos Santos, Elisan dos Santos Magalhães
Presenter: Rodrigo Gustavo Dourado da Silva
doi://10.26678/ABCM.COBEM2023.COB2023-1333
Abstract
In the oil and gas industry, one of the most critical stages of offshore platform decommissioning is the wellbore plugging and abandonment (P&A) operation. Decommissioning standards require that, at the end of its lifespan, the wellbore be permanently sealed in order to prevent the leakage of contaminating fluids into marine ecosystems. The current decommissioning operation comprises removing the production tubing, machining the borehole casing, and cementing the machined section to seal the wellbore. Such an operation has a relatively high cost and several risks. Furthermore, the cementation does not guarantee permanent sealing due to microcracks that may appear in the cement body in the long term. An alternative technology for P&A operations is replacing cement with a metallic plug created by the thermite reaction. A thermite reaction can melt the wellbore elements, enabling the production tubing to be removed faster and creating an impermeable metallic barrier, reducing, consequently, the time and costs of P&A operations. While promising, this technology still needs further improvements to be successfully employed in real offshore oil fields. In this sense, numerical simulation is a useful tool to understand the temperature evolution inside the wellbore, optimize the parameters of the engineering problem, and design physical experiments. In this work, a two-dimensional axisymmetric finite element heat conduction model is proposed to simulate the thermite reaction inside a wellbore. The phase change of both thermite and wellbore components is calculated using the apparent heat capacity method. Also, a level set method is proposed to capture the phase change fronts and changes in thermite volume during the reaction process. The numerical results are presented and discussed.
Keywords
Plugging and abandonment, Thermite reaction, Numerical Modeling, Applied heat transfer
