Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Laplace Transform-Based Modeling of Heat Transfer in Producing Wellbores
Submission Author:
Eduardo Bader Dalfovo Mohr Alves , SC
Co-Authors:
Eduardo Bader Dalfovo Mohr Alves, Arthur Pandolfo da Veiga, André de Souza Matos Vicente, Jader Riso Barbosa Jr.
Presenter: Eduardo Bader Dalfovo Mohr Alves
doi://10.26678/ABCM.ENCIT2022.CIT22-0098
Abstract
This paper presents a novel, consistent approach to modeling heat transfer in hydrocarbon producing wells in order to simulate Annular Pressure Buildup (APB) in offshore wells. The modeling framework is built on a state-of-the-art APB simulator and adds to traditional (i.e., pseudo-steady-state) models, including terms initially neglected in transient simulations. For that, a formulation based on the Laplace transformation of the governing differential equations is constructed and solved in the transformed space. Subsequent inversion is performed numerically using the Abate-Whitt framework. The main objective of applying the transformation is to propose a better-suited formulation to simulate shorter timespans (of the order of hours and starting days), where traditional approaches are deficient. Data gathered from an actual oil-producing well validate the method, leading to two main sets of results. The first is a comparison against field data for temperature and pressure in the production line at the wellhead. In such a study, it is expected that the new Laplace-based model will adjust better to the actual field data. In the second study, the main result is a comparison of the APB in each annuli using the pseudo-steady-state simulator and the new Laplace model. From such a study, it is possible to analyze possible extra loads in the wellbore casings over shorter spans, which are expected to be less significant as the new transient model leads to slower temperature variations. Consequently, in case of better representation of the wellhead temperature, the slower warming of the annulus indicates that traditional models will overpredict APB, which could lead to excessive investments with safety factors in the construction of the wellbore. These statements are confirmed with preliminary tests, where a predicted difference of 8 MPa in the first annulus between the models indicates the importance of using this new heat transfer formulation to simulate the temperature distribution and the related APB.
Keywords
Laplace Transform, Wellbore, Heat transfer, petroleum production, APB
