Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Investigation on the Effects of Thermophysical Properties of Drilling Fluids on the Simulation of Thermally Driven APB
Submission Author:
Eduardo Bader Dalfovo Mohr Alves , SC
Co-Authors:
Eduardo Bader Dalfovo Mohr Alves, fernando freitas czubinski, Luís Gustavo Medeiros De Luca, Jader Riso Barbosa Jr.
Presenter: Eduardo Bader Dalfovo Mohr Alves
doi://10.26678/ABCM.ENCIT2022.CIT22-0164
Abstract
Drilling wellbores requires different fluids to balance the geostatic pressures from the pressurized hydrocarbons filling the rock formation and the weight of the rock column itself. However, once drilling is finished and the well starts producing, the drilling muds and completion fluids are kept trapped in the concentric annular spaces. As the hot reservoir fluids (produced fluid) rise inside the production tubing, they heat the entire wellbore structure, including the static fluids trapped inside the annuli, raising their pressures. If not correctly dealt with (i.e., prevented or remediated), the annular pressure buildup (APB) may result in collapse or burst of the casings or the production tube, this could lead to a premature end of the wellbore’s life cycle. Being a thermally driven phenomenon, APB is heavily influenced by the thermophysical properties of wellbore fluids. Despite the relatively large number of studies on the behavior of their volumetric and rheological properties as a function of pressure and temperature, there is much less literature on thermal properties (thermal conductivity and specific heat capacity) of drilling and completion fluids, specially for fluids with synthetic or oil bases. In this paper, a short overview of the literature on the thermophysical properties of the different wellbore fluids (brines and water, oil and synthetic-based muds) revealed a significant scatter of the specific heat capacity (over 50%) and thermal conductivity (30%) predictions according to the most popular correlations. Furthermore, when incorporated into a mathematical model to compute the annular pressure behavior, such variations lead to changes in APB greater than 4 MPa at the start of production. Finally, the paper presents new experimental data on the thermal conductivity and specific heat capacity of completion and drilling fluids as a function of temperature and pressure, enabling the formulation of improved correlation methods for actual oil producing wellbores application.
Keywords
thermal conductivity, Specific heat, Emulsion, drilling fluid, APB
