Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
EXPERIMENTAL INVESTIGATION OLEFIN-BASED INVERTER DRILLING FLUIDS ON HPHT CONDITIONS: APPARENT VISCOSITY PREDICTION IN DIFFERENT OIL/ WATER RATIOS
Submission Author:
LUIS HUMBERTO QUITIAN ARDILA , PR , Brazil
Co-Authors:
LUIS HUMBERTO QUITIAN ARDILA, GÉSSICA PALAORO, Diogo Elias da Vinha Andrade, Admilson Franco, Elessandre Souza, alex waldmann
Presenter: LUIS HUMBERTO QUITIAN ARDILA
doi://10.26678/ABCM.COBEM2023.COB2023-0364
Abstract
Drilling fluids are essential in the oil and gas industry to help maintain wellbore stability, cool and lubricate the drill bit, and carry cuttings to the surface. In high-pressure, high-temperature (HPHT) conditions, these fluids face unique challenges due to the extreme environment they are subjected to. One of the main challenges of drilling fluids in HPHT conditions is maintaining their rheological properties, such as viscosity and yield strength. These properties are crucial for effectively carrying cuttings to the surface, and they can be impacted by the high temperatures and pressures present in HPHT wells. The objective of this work is to analyze the dependence of the oil-water ratio and density on the viscosity of drilling fluids with NaCl, as well as to fit the viscosity variation with shear rate, temperature, and pressure. Olefin-based drilling fluid with two different oil-water ratios (60/40 and 70/30) and three different densities (11.5 ppg, 10 ppg, and 8.5 ppg) were rheologically characterized. Steady-state flow curves were developed at temperatures of 4, 65, 93, 121 ºC and atmospheric pressures of 70, 270, and 550 bar. The experimental data were collected on a Mars 60 rheometer (Haake, Germany) coupled with a D600/250 pressure cell. The results showed that the shear stress decreases with increasing temperature and the oil-water ratio and improves with increasing pressure and density. The temperature variation from 4 to 121ºC decreased approximately 84% in the 60/40 fluid and 55% in the 70/30 with 8.5 ppg at the shear rate of 510.9 s^(-1). We can see that between lower oil-water ratios, better capacity has the drilling fluid in HPHT conditions. In the case of pressure, shear stress increases in both 60/40 and 70/30 fluids. On the other hand, increasing the density increases the shear stress, as expected. Increased from 12.8% (8.5 to 10 ppg) and 21.7% (8.5 to 11.5 ppg) in 60/40 fluid, and 30.0% (8.5 to 10 ppg) and 53.2% (8.5 to 11.5 ppg) in the 70/30, when comparing the values of shear stress at 4 ºC, atmospheric pressure, and 510.9s^(-1). Then, the experimental viscosity data were fitted as a function of temperature, pressure, and shear rate.
Keywords
Drilling fluids, apparent viscosity, OIL/ WATER RATIOS, HPHT, Offshore fields
