Study On Terahertz Spectra Of High-water-cut Crude Oil Based On 3D Printing Technology

Geological conditions in China are very complicated,oil field development depends on water injection.The major mining period for proven recoverable reserves in China is the high water cut stage,and changes to ultra-high water cut stage gradually.Thus,the evaluation of water content in crude oil is of significance to petroleum exploration and transportation.Terahertz(THz)wave is sensitive to the fluctuations in dipole moment of the water.However,due to the strong absorption of water in THz range,it is difficult to determine the high water content using THz spectrum with the common sampler.In this research,aiming at the technical problems in the terahertz study of high water cut crude oil,a sub-millimeter 3D printing sampler suitable was designed and manufactured.We tested the samplers with different sizes and printing parameters.Based on the test results,the design scheme was optimized and the optimal solution was obtained.The 3D printing samplers were detected using terahertz technology,and an error analysis method for 3D printing technology was established.The results shows the average error of the entity is 2.47%,and the average error of the gap is 0.96%.Micron-grade samplers for THz detection were designed and manufactured using additive manufacturing(AM)technology.Oil-water mixtures with water content from1.8% to 90.6% were measured with THz-TDS system using the sample cells.A detailed analysis was performed about the relationship between the THz parameters and high water content over 60%.The results suggest that the combination of THz spectroscopy and AM technique is effective for water content evaluation in crude oil,which can be further applied as a new technical selection in petroleum industry.