On-Line Monitoring Technology of Residual Concentration of Corrosion Inhibitor inOil-Field Produced Fluid and Its Application

An on-site detection method of corrosion inhibitor concentration in oil and gas fields and a mobile on-line analyzer are introduced. The analyzer uses ultraviolet (UV) spectroscopy and chromogenic agent technology to measure the residual concentration of corrosion inhibitor in oilfield produced liquid. The instrument uses a long-life pulsed xenon lamp as the light source, and the monochromator is a diffraction grating. The ultraviolet light is introduced into the flow colorimetric cell through the grating, and the transmitted light is introduced into the photodiode array (PDA) through the optical fiber. Under the control of microprocessor, the analyzer can perform rapid UV spectral scanning and residual corrosion inhibitor concentration measurement on oilfield produced fluid. In order to prevent the residual oil in the sewage from polluting the flow colorimetric tank, the front end of the monitor uses a filter column for preliminary oil-water separation. After the separation, the fluid is automatically pressed into the flow colorimetric tank by a peristaltic pump for UV spectral analysis. The absorbance-concentration standard curve was established in advance, and then the residual concentration of the corrosion inhibitor in the water was calculated from the absorbance of the running water.