Mass Spectrometric Calibration for Real -Time Hydrocarbon Detection

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. However, development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids is always a challenging issue because of lack of a robust, quick and effectively selective instrument and method. The primary goal of this research is to understand reasons of such discrepancies in results between “good” spectra, and “poor” ones. The objectives are thus to identify the detection issues, calibrate and QA/QC the instruments, and analyze the results in lab settings. In this study, we used two mass spectrometers (loaned by Halliburton to LSU) to develop a more selective and precise method to quantitatively analyze low level lighter analytes like lighter hydrocarbon (C1- C6) with masses \u3c75m/z at concentrations (10, 15, 100 & 500ppm). In addition, heavier hydrocarbons and non-hydrocarbons were also detected. The C1 to C10 compounds and other gases had m/z ranging from 2 to 200. Our results suggest that using methane 15, ethane 26, propane 41, butane 43, pentane 73 and hexane 87 base masses can help detect these hydrocarbon components from gas streams in live well fluids. The mass spectrometers worked well and had good spectrometric resolutions and detection for some samples, however, the systems appeared to have issues with detection, spectra deconvolution, and quantification of analytes at lower concentrations