Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Rheological study of hydrate slurries in water-based drilling fluids
Submission Author:
Guilherme Mühlstedt , PR
Co-Authors:
Guilherme Mühlstedt, Diogo Elias da Vinha Andrade, Cezar Otaviano Ribeiro Negrao
Presenter: Guilherme Mühlstedt
doi://10.26678/ABCM.ENCIT2022.CIT22-0669
Abstract
One of the major risks in deep-water operations is the hydrate formation due to harsh conditions such as high pressure and low temperature. Hydrates are crystalline structures resembling ice that are formed by small molecules, such as light hydrocarbons, occluded in a cage-like structures composed of water molecules. Unexpected events such as a hydrocarbon influx to the wellbore during drilling procedures might result in hydrate formation in the water-based drilling fluid. Understanding the rheological properties of the system is crucial for ensuring suspension transportability or an eventual breakage of agglomerates jammed along the process. In this work, the rheological influence of the hydrate formation in a water-based drilling fluid, mainly composed of water (79%) and sodium chloride (14%), provided by Petrobras, was investigated under static and dynamic conditions. Tetrahydrofuran (THF) was used as a guest fluid. The guest fluid cut was set to hydrate structures not exceeding 40% in volume to ensure that the sample behaves as a liquid suspension. Rheometric tests revealed that the slurry formed by the suspension of hydrate crystalline structures was a time-dependent elasto-viscoplastic material in which the microstructure is irreversibly affected by the imposed shear.
Keywords
Rheology, drilling fluid, Well drilling, Hydrates, Hydrate Slurry Flow
