Experiment of high-temperature and high-pressure rheological characteristics of oil-gas-water fluid

Taking the Daqing waxy crude oil as an experimental media and adopting self-made high-pressure rheological characteristics test system, viscosity-temperature characteristics of oil-gas phase and oil-gas-water phase under different shear rates, water content ratios and pressures are tested when the experimental oil samples are under pressurization by nitrogen and natural gas, and the influences of nitrogen and gas solubility on WAP and WDT of the waxy oil are discussed. Results indicate that under pressurization by nitrogen and natural gas, apparent viscosities of oil-water mixtures and oil-gas-water mixtures are both reduced with the increase of shear rate, and shear thinning effects are more obvious when the temperature is lower. Under the same pressure conditions, the apparent viscosity of oil samples increases with the increase of water content ratios when the l water cut of crude oi is lower than 20%. Under the condition of being lower than bubble point pressure, WDT and WAP of oil-gas-water mixtures and oil-gas mixtures decrease with the increase of pressure when natural gas is used for pressurization, and the change law is on the contrary when the nitrogen is used for pressurization, and it is indicated that the natural gas dissolving in the crude oil is in favor of improving flow of crude oil.