A New Type Of Water-mixed Flowmeter Design And Flow Field Fistribution Law Research

Oil mixing with water is a common oil and gas gathering and transportation process.The amount of water mixed has a significant impact on the safe operation of the gathering system and the energy consumption of the system.If the amount of mixed water is too large,the energy consumption of the system will increase;if the amount of mixed water is too small,the operation safety of the gathering and transportation system will decrease.In actual production,the amount of water mixed is mainly achieved by manipulating the water mixing valve based on experience,which is difficult to measure effectively.For most of the built measuring rooms,since the initial design does not take into account the flow measurement of water mixing,the remaining space is narrow,and it is difficult to install traditional flowmeters such as electromagnetic flowmeters and vortex flowmeters.In addition,due to the huge difference between the amount of mixed water and the amount of hot wash water,the traditional flowmeter is difficult to meet the measurement problem with a large flow range.In view of this situation,considering the requirements of narrow installation space and wide measurement range,a new differential pressure type water mixing flowmeter was designed.The main contents are as follows:An L-type differential pressure flowmeter is designed,and the internal flow field pressure and velocity distribution at different flow rates are simulated,and the influencing factors and changing trends of the outflow coefficient are analyzed.Due to the fixed throttle aperture,the flow range of the flow meter is relatively small.When the flow rate reaches 25m3 / h,the pressure upper limit of the differential pressure sensor has been reached.In the water-mixed oil collection process,the flow rate during hot washing and cleaning of wax is often higher than 30m3 / h.At this time,the differential pressure sensor will be damaged,resulting in unreliable flow measurement results,and further structural improvement is required.Based on the L-type differential pressure flowmeter,in order to meet the flow measurement requirements under the conditions of small flow mixing water and large flow hot wash,its structure has been improved,and a tower flowmeter has been designed.The internal structure of the flowmeter is mainly composed of throat pipe,shunt tower and spring.When the flow rate is small,the compression amount of the spring is small,and the flow area between the diverter tower and the throat is small.In the case of a small flow rate that cannot be measured by an ordinary orifice flowmeter,a measurable differential pressure will be generated,and the sensitivity will be higher;When it is large,under pressure,the spring compresses,the diverter tower retreats,the fluid flow area increases,and the pressure difference of the pressure measuring tube will not increase too high,which can prevent the problem of damage to the differential pressure sensor caused by excessive flow.The flow field distribution law of the newly designed tower flowmeter is numerically simulated,the distribution law of internal flow field under different flow rates is analyzed,and the feasibility of the application of the new flowmeter under the conditions of small flow mixing water and large flow hot washing is verified.Sex.On this basis,in order to further improve the measurement reliability,the key structural parameters of the flowmeter,the angle of the distribution tower,the diameter of the throat pipe and the length of the throat pipe were optimized by numerical simulation.Using the calibrated water flow device provided by the Quality and Technical Supervision Bureau of Daqing Oilfield Co.,Ltd.,the tower L-type flowmeter was calibrated by the static mass method,and the functional relationship between flow rate and pressure difference was established to verify the reliability of the numerical simulation..In the process of water mixing measurement,the mixed medium is sewage.For the polymer flooding block,the sewage also contains polymers,which causes its viscosity to be higher than that of clean water.Big deviation.In response to this problem,the influence of viscosity on the measurement results was analyzed,and a flow correction method was given.