Abstract

Spectroscopic methods of analysis have been developed for the determination of treating chemicals in oilfield water systems.

Part 1 describes a xenon flash photometer (XFP) that was designed for on-line measurements under harsh, oilfield conditions. The instrumentation is capable of absorption and fluorescence measurements in the ultraviolet and visible spectral ranges. Chemicals are determined by virtue of their ability to absorb or emit light at characteristic wavelengths. Light signals are carried between a central photometric console and remote analysis sites by fiber optic cables, eliminating the need for troublesome flow-through cells. Aspects of instrument design, drift compensation, and calibration methodology are discussed. Laboratory and field data are presented.

Part 2 describes the potential of short-wave ultraviolet spectroscopy for the simultaneous determination of multiple treating chemicals in supply water. Absorption measurements at wavelengths between 190 and 250 nm are shown to yield part-per-million sensitivity for a wide range of chemical products. The severe spectral overlap, which has previously limited the analytical utility of this portion of the spectrum, is overcome by multivariate calibration. Using this technique, a scale and corrosion inhibitor were simultaneously determined from a single spectrum with approximately 2% relative error.