Study On The Oilfield Injection Water Online Detection System Using Scattering And Fluorescence

We usually use underground injection water in the oilfield to ensure the pressure of the oil layer.The content of suspended solids(SS)and oil determine the injection character of water and the life span of the system,playing a key role in oil production.This paper is supported by the project of “The research and experiment of oilfield injection water online measuring device” from Sinopec,owing to design a small and precise device for the oilfield injection water measurement.By researching on the optical character of SS and oil particles,the paper worked out the approach of underwater scattering combined with surface fluorescence and established online measuring system to accomplish the experiment.The paper finally accomplished the data acquirement and method verification in the laboratory.The main points are as follows:1.Compared measuring methods of SS and oil separately,define the underwater scattering method for SS and surface fluorescence method for oil based on the requirement of online detecting and the optical character of particles.2.Modelled the two methods based on Mie scattering theory and UV fluorescence effect.The modeling process has taken the indirect impact of absorption and scattering from SS,oil and water molecule into consideration,simulated the influence made by the change of parameters such as particle diameter,wavelength,optical length etc.,finishing the experimental verification of the underwater scattering method and the surface fluorescence method.3.Proposed the comprehensive method called “fluorescence first,scattering later” by discussing the influence between SS and oil measurement.4.Designed the optical structure and parameters properly according to the small size requirement of oilfield pipes.Researched on the errors and optimization of the optical structure.5.Designed and debugged the hardware circuits,chose proper devices.Proposed the basic structure of the photoelectric detection module and the specific designing approaches,such as feedback stabilized circuits and small signal processing circuits.Analyzed photoelectric noise and ways to increase SNR.6.Established the oilfield injection water measuring platform,collecting the measuring data and analyzing the error under the laboratory circumstance.The result proved that the oilfield injection water detecting method is feasible and the system meets the preliminary requirement of injection water measurement.