Evaluation of the Extraction Method and Characterization of Water-Soluble Organics from Produced Water by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

摘要

An alternative method to extract, quantify, and characterize water-soluble organic (WSO) species in produced water from steam-assisted gravity drainage (SAGD) is evaluated by various techniques. Here, we use a 70:30 mixture of cyclohexane/butyl acetate as the solvent for extraction of WSO species from produced water. The ability of the 70:30 cyclohexane/butyl acetate mixture to efficiendy isolate higher O_x species that are readily identified in production deposits is demonstrated by use of Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometric analysis and fluorescence spectroscopy. These results are compared to industry standard methods that employ extraction with n-hexane and cyclohexane. Results reveal that the 70:30 cyclohexane/butyl acetate solvent system not only extracts more material from produced water than n-hexane or cyclohexane but is also more efficient at extraction of polar species implicated in deposits of interest. Results suggest that a 70:30 cyclohexane/butyl acetate mixture is a better solvent for the quantitative extraction and analysis of WSO in produced water.