Multiparametric Flow-Through Measuring Complex for Express Control of Oil Quality Using a Proton Magnetic Resonance Relaxometry Method

The paper discusses the problems arising during quality control of the raw materials (e.g., borehole fluid, crude oil, and oil–water emulsions) in the processes of their production, conditioning for transport, and processing. It is shown, that the existing means of express control of oil quality have low accuracy and insufficient speed of measuring oil characteristics. To ensure the quality of oil and purity of the separated ballast water, their additional purification is necessary. To perform the express control of oil characteristics (properties) during its production, conditioning and transportation, a proton magnetic resonance relaxometer and a multiparametric flow-through measuring complex with a representative sampling system have been developed. A method of nuclear (proton) magnetic resonance relaxometry, configuration and functioning algorithm of the measuring complex, as well as the structure and operation of the proton magnetic resonance relaxometer are described. Equations describing technical, electromagnetic, and circuit parameters of the relaxometer have been obtained. The relaxometer underwent metrological testing as part of the measuring complex during express control of the properties of oil samples. The following measurement errors of the characteristics of borehole fluid, crude oil, oil–water emulsions, and ballast water separated from oil were obtained: ±1% (relative error) for water content in oil in the range from 0 to 100%; ±0.2 mg/L for salt concentration in water in the range from 0 to 10 g/L; ±0.3% (relative error) for sulfur content in oil in the range from 0.1 to 8.0 abs.%; ±1.47 kg/m3 for oil density in the extended range from 700 to 1100 kg/m3; and ±0.13 mm2/s for kinematic viscosity of oil in the range from 0 to 350 mm2/s. The oil samples were characterized using analytical laboratory techniques. The introduced measuring complex enables data verification based on several parameters obtained using proton magnetic resonance relaxometry. The developed flow-through measuring complex can be used when controlling a multifunctional automated digital smart well, as well as equipment for separating water from the oil–water emulsions and treating produced water.