| Oil and gas industry is the lifeblood of national economic development,multiphase flow is common in the petroleum industry.Now the research on the flow law of multiphase flow is very extensive at home and abroad,especially in the oil-water two-phase flow measurement,the development of logging tools is mature,and the three-phase flow is complex and changeable.There are many technical problems in this field that need to be solved by scientific researchers and technicians.The three-phase flow measurement is mainly concentrated in the surface measurement,and the surface and downhole conditions are quite different.The surface measurement don't accurately reflect the actual situation of underground fluid,especially the changes of reservoir formation properties.It is very important to accurately measure the content of oil,gas and water three-phase flow in the wellbore for reservoir dynamic monitoring,which paves the way for digital oilfield and intelligent oilfield management in the future.In view of the characteristics of low yield liquid,high water cut and associated gas of downhole fluid in the late development stage of domestic oilfields,the bubble flow with oil and gas as dispersed phase and water as continuous phase is the main research object.A gas-liquid phase separation theory and prototype model based on Jamin effect are proposed in this paper.Through gas-liquid separation method,multiphase flow can be separated in the separation device Each phase is separated through different flow channels to reduce the mutual interference of each phase measurement,so as to solve the problem that the gas is not easy to be measured in real-time underground in the current multiphase flow measurement,which has great interference to oil and water and causes inaccurate oil and water measurement.In this paper,by calculating the pressure of oil gas water three-phase passing through holes with different diameters,the difficulty of oil gas water three-phase passing through holes is judged,and the conditions of gas-liquid separation are analyzed.The gas-liquid separation model is established by numerical simulation technology,and the grid is divided and the design parameters are optimized.By analyzing the gas-liquid separation under different flow and content,the structure model is optimized.Combined with the three-phase flow laboratory conditions,a reasonable separation device prototype is designed,and the multi-phase flow chamber experiment is carried out to verify the feasibility of gas-liquid separation effect and the multi-phase flow measurement effect.The research results indicate that the separation device can realize the gas-liquid separation of low multiphase flow in vertical wells,the separation effect of multiphase flow is obvious,the separation interface of each phase is clear,which verifies the feasibility of the gas-liquid separation method in the separation device,the gas-liquid separation efficiency is high,and the design purpose is achieved.The hole's parameter set in the prototype have obvious effect on gas-liquid separation,which verifies the reasonable application of Jamin effect in the device.In order to improve the measurement accuracy of gas and reduce the interference of gas to oil-water measurement,it is helpful to ensure the measurement accuracy of oil-water two-phase flow. |
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