The testing study of the temperature limit for oil-gas-water mixed transportation during oil production with special high water-cut

With oil extracting, the water-cut in rude oil increased continuously in Daqing oil field. About 90 percent of the liquid production is water in most of the oil wells. With the increase of water-cut, the energy consuming to gather and transport per ton rude oil has grown sharply. In order to gather and transfer oil safely without heating, reduce the energy consuming and production cost, we set up a suit of device in Daqing oilfield. We test the pressure drop and the flow pattern of oil-gas-water that is produced in No.6 Oil Extraction Factory with different temperature, different water-cut, different output capacity, and different gas capacity. The results of the test indicate that if the water-cut of mass exceeds 85%, the amount of produced liquid is between 11 and 105t/d, the ratio of gas and oil is between 40 to 60m 3 /t, the flow rate of oil-gas-water mixture is from 0.2 to 2m/s and the conversion rate of the gas is from 0.15 to 1.8m/s, the flow of oil- gas- water in the horizontal pipe belong to slug flow. Sometimes the oil and water are separated and oil floats on the water, sometimes the oil is wrapped and is dispersed by water. By analyzing the test results, we conclude that the temperature limit of oil-gas-water for safe mixed transportation is lower than condensation point of oil with super high water-cut. It is 23� during testing range in Daqing oil field.