Experimental Study On Viscosity Reduction And Dehydration Of Tahe Oilfield Heavy Oil

Tahe Oilfiled is a typical deep-seated heavy oil reservoir,and Tahe heavy oil has features of high viscosity,density,colloid and asphaltene.Currently,viscosity reduction program has been employed at the NO.10 and NO.12 blocks by injecting intermediate crude oil into heavy oil reservoir.According to the production plan of 2016-2020,mass ratios of heavy oil and intermediate crude oil are controlled as 1:0.87 and 1:1.86.However,with the decline of intermediate crude oil production,the contradiction between supply and demand is increasingly outstanding.Meanwhile,dehydration temperature of NO.2 central processing facilities is up to 85-90 degrees,resulting in severe energy consumptions.Therefore,it's important to optimize viscosity reduction program with less intermediate crude oil and dehydration parameters with less energy consumptions.According to the present viscosity reduction and dehydration program of Tahe Oilfield,kinds of viscosity reducers and dehydrating agents are tested and the optimal one is selected through experiment.Viscosity reduction effects of extra addition of light crude oil and viscosity reducer are evaluated.Dehydration experiments on mixed crude oil samples with different water content are conducted to determine optimal dehydration parameters such as dosage of dehydrating agent and dehydration temperature.Finally,economic benefits of each viscosity reduction and dehydration program are calculated.Research shows that after using the suggested viscosity reduction program,dehydrating agent and dehydrating parameters determined from this work,the economic benefits of crude oil at the NO.10 and NO.12 blocks increase by 11.50 yuan and 32.70 yuan per ton and dehydrating costs of heavy oil reduce by 0.46-0.90 yuan per ton.