Multi parameter and Novel Technologies for Detection of Crude Oil in Seawater

Transcription

1 Multi parameter and Novel Technologies for Detection of Crude Oil in Seawater MTS Subsea Leak Detection Symposium Ian Walsh Director of Science, Sea Bird Scientific November, 2014

2 Previous Work Wave tank simulations for improved oil spill research monitoring: Multichannel fluorescence, insights into oil dynamics, and novel in situ sensors P.G. Coble, C. Koch, M. Abercrombie, I. D. Walsh, R.N. Conmy, K. Lee, A.M. Wood IN SITU TRACKING OF OIL FROM THE DEEPWATER HORIZON OIL SPILL USING SPECTRAL FLUORESCENCE Corey Koch, 1 Paula Coble, 2 Leslie Slasor, 3 Joseph Needoba, 3 Andrew Barnard, 1 Scott Pegau 4 Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site; Geophys. Res. Lett., 37, L20602, doi: /2010gl Diercks, A. R., R. C. Highsmith, V. L.. Asper, D. Joung, Z. Zhou, L. Guo, A. M. Shiller, S. B. Joye, A. P. Teske, N. L. Guinasso Jr., T. L. Wade, and S. E. Lohrenz (2010): The Fluorescence Intensity Ratio (FIR): A New Way of Assessing the Efficiency of Oil Dispersion. J.B.C. Bugden1, P.E.Kepkay2 and B.D. Johnson2

3 Crude Oil Detection Deep Water Horizon response Deep Water Horizon lessons Spectral Fluorescence Oil Fluorescence response model DUV Instrumentation

4 Water Column Sampling CTD Rosette with O2 sensor and Transmissometer R/V Pelican 12 Niskin bottles O sensor 2 WET Labs c Star Transmissometer Sea Bird Model 911 CTD Conductivity Depth Temperature SBE 43 DO

5 DWH Profiles Pelican Site nm SW Site nm SW

6 DWH Sections

7 CDOM Fluorescence and PAH samples from depths greater than 800 m Omission of the highest PAH value still resulted in a significant correlation with an r 2 value of 0.731

8 Map View

9 In situ tracking JAG_Report_1_BrooksMcCall_Final_June20 Right: WL ECO (370/460 nm) and neat LA Sweet crude oil. Left: Visible Oil fluorescence

10 What causes oil to Fluoresce? Polycyclic aromatic hydrocarbons Highly toxic to aquatic life, known carcinogens Fluorescence signatures shift due to alkylation and energy transfer effects Fluorescence correlated to API gravity, viscosity, aromaticity Oil in water forms: neat (slick), emulsion/colloid (mousse, dispersion), dissolved hydrocarbons Weathering can transform signals Photo: Dave Martin/AP

11 Excitation Emission Matrix Spectra Incrementally change excitation wavelength and measure entire emission spectrum Provide fingerprint of steady state fluorescence EX EM

12 Excitation Emission Matrix Spectra Oil has distinct fluorescence regions compared to CDOM Oil Fluorescence varies with sample site and depth aging and associated tranformations EX

13 Experimental Data ES&T Conmy et al 2014 Figure 1. Fluorescence EEM of chemically dispersed fresh MC252 oil (4 ppm) concentration in a EXP DIL. Center Wavelengths (CWL) of Chelsea Technologies Group AQUAtrackas ExEm239/360 and ExEm239/440 ( ), Turner Designs Cyclops ExEm320/510 ( ), and WET Labs, Inc. ECO ExEm370/460 ( ) along with the fluorescence intensity ratio (FIR = ExEm280/340: 280/445; ) are overlaid for reference

14 Experimental Data ES&T Conmy et al 2014 Fluorescence intensity of the ECO and AQUA239/360 nm sensors exposed to chemically dispersed MC252 crude oil during EXPADD within the wave tank.

15 Oil Fluorescence response model Fluorescence intensity minimum per unit mass Fluorescence spectral response maximum red shift Fluorescence intensity increasing per unit mass Fluorescence spectral response decreasing red shift increasing blue

16 Experimental Data

17 Experimental Data

18 New Instrument MCOMS MCOMS fdom has 4 7 x resolution of ECO CDOM MCOMS dynamic wide range technology makes saturation highly unlikely