Research On Measuring Method Of Oil-water Two-phase Flow Velocity Based On Thermal Tracing

With the continuous deepening of oil and gas exploration and development technologies,small-diameter oil well development technologies have been proposed.In view of the current low oil production in domestic oilfield development,the development of small-diameter oil wells has the characteristics of enhanced recovery and low cost,which can effectively increase the output of domestic oil and gas fields.Liquid production test data of different production layers in oil wells has important guiding significance for the development and operation of oil field recovery.The production wells in domestic oilfields are mainly high water cut wells,medium and low production fluid wells,and the measurement methods and measurement ranges of foreign test instruments are not suitable for domestic situations.As the oil field enters the middle and late stages of production,the water content in the well has increased and even reached an extremely high water cut state.In order to improve the recovery rate,technologies such as chemical flooding and horizontal well mining are often used.However,due to the high viscosity of the downhole fluid and the serious sand production,the sand jam of the commonly used flow velocity measuring instrument fails,which brings new problems to the logging.Aiming at this problem,a method for measuring the flow rate of ultrahigh water-bearing oil-water two-phase flow based on thermal tracing is proposed,and the parameters of the flow rate measuring instrument based on the thermal tracing method are optimized.The shape and material of the heat source of the measuring instrument,the installation position of the thermistor probe and the heating power of the heat source were numerically simulated and verified by experiments.Through numerical simulation,the best parameters of the horizontal well thermal tracer flowmeter are: the heat source material is aluminum,the shape is rectangular,the distance between the thermistor probe and the heat source is 200 mm,the pulse heating power of the heat source is 350 W;the vertical well heat The best parameters of the tracer flow meter are: the heat source material is aluminum,the shape is rectangular,the distance between the thermistor probe and the heat source is 200 mm,and the pulse heating power of the heat source is 200 W.The thermal tracer velocity measuring instrument was designed and prepared according to the best parameters of the heat source shape and material,the installation position of the thermal probe and the fluid heating power obtained by the simulation,and the vertical and horizontal wells were tested and verified by the velocity meter.The experimental results show that the measurement accuracy of the thermal tracer flow meter is 4%,and the repeatability is 2.6%.The measurement accuracy of the flow rate is not affected by the water holding capacity and sand content.The experimental results show that the temperature signal curves measured by the experimental prototype are good and relevant.The experimental flow rate and the standard flow rate under different water cuts have a good linear relationship.The instrument is in the horizontal well 0.0491-0.491 m/s and the vertical well 0.0491-0.245 m/s the measurement at a flow rate of shows good repeatability with a systematic error of less than 5%.The instrument has been initially applied to domestic oilfields.It is suitable for high water cut and low production fluid production conditions.It has no moving parts and can be used to measure the flow rate of sand wells.