| Today,with the rapid economic development,my country’s demand for oil is also increasing.At present,the continuous exploitation of crude oil has led to the middle and late stage of the exploitation of most domestic onshore oil fields.In this stage,the oil wells are mostly exploited by water injection and pressurization.The water injection in the oil wells makes the three phases of oil,gas and water widely exist in the oil wells,as well as the phenomenon of high water cut and low oil production caused by longterm water injection.In order to reduce the oil production cost and formulate a reasonable oil production scheme,the development of oil,gas and water three-phase flowmeter is urgently needed for crude oil production.The three phases of oil,gas and water will be affected by temperature,pressure,flow rate,oil quality,water quality and the composition of each phase during the flow in the pipe,resulting in complex and changeable flow patterns,and it is very difficult to detect the relevant parameters of each phase.At present,there are still few threephase flowmeters actually used in oil wells,and the three-phase flowmeters used in most oil wells are separated flowmeters.This kind of flowmeter covers a large area,has high cost,is difficult to maintain,and is difficult to realize real-time online measurement.This paper takes the three-phase oil,gas and water with near-laminar flow,low flow rate and high water content as the main research object,and designs a flow metering device that can be installed on the oil pipeline and does not require threephase separation.This device adopts a measurement scheme combining multiple sensors such as capacitive sensor,differential pressure sensor,and flow rate sensor.The capacitive sensor measures the proportion of water phase,and the differential pressure sensor measures the proportion of oil phase.At the same time,the gas phase proportion is obtained.The flow rate sensor measures the fluid flow rate and realizes the measurement of each phase flow through the proportion and flow rate of each phase.Through computer software simulation and combined with the specific experimental results in the laboratory,the design and verification of this measurement scheme are completed,including the structural design of the capacitive sensor,the selection of the differential pressure sensor and the structural design of the flow rate sensor.The device uses STM32F429IGT6 as the main control chip to design the hardware circuit of the control system,designs the hardware detection modules of each sensor around the main control system,and designs the software programs corresponding to each hardware part.Finally,the three-phase experiments of oil,gas and water are carried out in the laboratory.The experimental results show that the measurement results reach the expected goal when the three-phase flow is in the state of low velocity and near laminar flow.The measurement plan will provide evaluation data for the production management of oil wells,realize cost reduction and efficiency increase and scientific management of oilfield production,and has the advantages of low cost,no radioactivity,real-time online measurement,and easy installation and maintenance,etc. |
