Subsea Dispersant Injection (SSDI) Use, Potential, Challenges and Future R&D Needs

Transcription

1 Subsea Dispersant Injection (SSDI) Use, Potential, Challenges and Future R&D Needs Per Johan Brandvik Senior Scientist & Professor SINTEF - Marine Environmental Technology Trondheim, NORWAY 1

2 Subsurface release WITHOUT dispersant dispersant injection injection Oil droplets surface forming thin oil slick Multi millimeter oil droplets? Multiple 100 micron oil droplets..? Low VOC exposure High VOC exposure Outflow of oil and gas Plume of entrained water, oil and hydrate/gas Smaller Large oil droplets stayes rise vertically longer in (hours) the plume resulting and rise in a slower thick surface (days) slick wider/thinner directly above less persistent the release surface point slick high (reduced VOC exposure emulsification & an & emulsifying/persistent increased natural dispersion) oil slick

3 Subsurface release WITHOUT dispersant dispersant injection injection d 50 = 2.3 mm d 50 = mm Release conditions: D: 0.20 m, 6000 m 3 /day, waxy crude, t: 54 C and GOR: 500

4 Subsurface release WITHOUT dispersant dispersant injection injection Mass balance 100 % Scenario m3/day, GOR GOR 500, 500, m m depth, No SSDI, No No wind 90 % 80 % 70 % 60 % 50 % 40 % 30 % 20 % 10 % d 50 = mm d 50 = 2.3 mm Evaporated Surface Dispersed Cleaned Sediment Stranded Biodegraded Outside Grid 0 % Time (days) Release conditions: D: 0.20 m, 6000 m 3 /day, waxy crude, t: 54 C and GOR: 500

5 Subsurface release WITHOUT dispersant dispersant injection injection d10 dm/s 50 = 2.3 mm 50 = surface wind mm 5 m/s surface wind Release conditions: D: 0.20 m, 6000 m 3 /day, waxy crude, t: 54 C and GOR: 500

6 SSDI R&D program overview Research topics : Release orifice, flow rates & injection techniques Oil properties versus dispersant products Combined releases of oil & gas Deep water release at high pressure (SwRI) Large-scale verifications at Ohmsett (SLRoss) Regulating dispersant dosage Monitoring droplet sizes documenting effectiveness How to screen products, select the best dispersant Next: Verification by a deep water field experiment..?

7 Acknowledgement A significant part of this presentation is based on research initiated by the American Petroleum Institute (API): API D3 JITS on Subsea Dispersant Effectiveness. More details available on: Results also from studies funded by individual oil companies like; BP, Statoil, Wintershall and Lundin and as a part of SINTEFs participation in the GOMRI DROPPS consortium. Thanks also to scientists, technicians & engineers at SINTEF, Ohmsett/MAR, SL Ross and SwRI for dedicated teamwork during these projects.

8 Small-scale releases SINTEF tower basin Click for video Subsea release of oil (Nozzle: 1.5 mm,1.5 L/min), dispersant injection (1% C9500) SINTEF Tower Basin

9 Small-scale releases SINTEF tower basin Click for video Subsea release of oil (Nozzle: 1.5 mm,1.5 L/min), dispersant injection (1% C9500) SINTEF Tower Basin

10 High Pressure (deep water) testing

11 High Pressure testing at SwRI, Texas, USA Hyperbaric chamber (5 x 2.2 m) Testing October 2015: Live oil & gas + Dispersants

12 Oil droplet size Oil droplet sizes at 5 & 1750 meters depth Relative droplet size distribution (Vol. %) Oil Oil alone alone 1 Amb Amb 14 Oil Oil alone alone 1 Amb HP HP Oil DOR alone 1:100 1 HP 1 Amb DOR Oil alone 1:100 1 Amb 12 DOR DOR 1:100 1:100 1 HP Amb DOR DOR 1:100 1:100 1: Amb HP DOR 1:50 Amb 10 DOR 1:50 1 Amb HP High Pressure (1750 m) Ambient Pressure (5 m) Droplet size (microns) Oil droplet sizes (microns) as a function of dispersant treatment and pressure

13 High Pressure (deep water) testing including natural gas and "Live oil"

14 Oil droplet sizes (d 50 ) "Live Oil" & natural gas (constant 175 atm) u = 3.5 m/s u = 4.0 m/s u = 5.4 m/s u = 9.9 m/s Oil droplet sizes as a function of gas void fraction and dispersant injection.

15 Oil droplets size (d50 microns) Oil droplet sizes (d 50 ) "Live Oil" & natural gas (constant 175 atm) Droplets-Exp3a-Live oil1 Droplets-Exp3b-Liveoil1-C9500 Droplets-Exp5a-Liveoil2 Droplets-Exp3a-Live oil1 Droplets-Exp5b-Liveoil2-C9500 Droplets-Exp3b-Liveoil1-C9500 Droplets Droplets-Exp5a-Liveoil2 (modified Weber scaling) Oil alone Droplets Droplets-Exp5b-Liveoil2-C9500 (modified Weber scaling) C Predicted droplet sizes (d 50 ) Modified Weber scaling (Johansen et al., 2013) Set Set gas gas void fraction (Vol%) Oil droplet sizes as a function of gas void fraction and dispersant injection.

16 Oil droplet size "Live Oil" & Natural Gas (5-175 atm) Oil droplet sizes as a function of depth (pressure) and dispersant injection.

17 Large scale testing to create realistic oil droplet sizes

18 Oppskalering av SINTEF's lab-resultater US Bureau of Safety and Environmental Enforcement (BSEE) Facility Ohmsett test tank: Length 200 m, width 20 m, depth 2.5 m and m 3 of sea water.

19 Upscaling to create more realistic oil droplet sizes

20 d 50 µm (Predicted - modified Weber scaling) Modified Weber - Measured vs. Predicted R² = 0, d 50 µm (Measured - SINTEF SilCam) 25 mm 32 mm 50 mm 25 mm - 1% C mm - 1% C mm - 1% C9500 SINTEF TowerBasin How will this work with mixed release of oil & gas..? Droplet size data. Nozzle sizes: mm & Oil flow rates: L/min.

21 How to monitor oil droplets (and gas bubble) sizes? To control: - SSDI effectiveness & - Dispersant dosage

22 The Monitoring Challenge Today Large oil droplets & gas bubbles Medium sized oil droplets Outflow of oil and gas Small oil droplets (a few microns..?) and water soluble components The only measurements available from DWH, measured > 1 km from wellsite..! None of the existing analytical platformas are able to cover the actual range of droplets sizes or detect gas bubbles

23 Options for Subsea Monitoring UV Fluorescence (e.g. Turner C3) Laser diffraction (e.g. LISST-100 or LISST DEEP) Holography (e.g LISST-Holo) Silhouette imaging (SINTEF SilCam) Relative changes in Concentration Particle size and concentration ( microns) Particle size and concentration ( microns) Good in Low concentration Particle shape Particle images Post processing Particle size and conc. ( microns) Good in high conc. Particle shape/type Particle images Oil & Gas differentiation High frame rate Real-time processing

24 UV Fluorescence (Turner C3) Laser diffraction (LISST-100) Holography (LISST-Holo) Silhouette imaging (SINTEF SilCam) ~Relative changes in Concentration Particle size and concentration ( microns) Particle size and concentration ( microns) Good in Low concentration Particle shape Particle images Particle size and concentration ( microns) Good in high concentrations Particle shape Particle images Oil v Gas differentiation High frame rate Progress from a 'line on a graph' to 'seeing' the data Trying to establish a "Intercalibration" study at Ohmsett..!

25 Norwegian oil companies wants to introduce SSDI as an oil spill response method in Norway How to monitor SSDI effectiveness during an subsea operation?

26 Tentative Concept Alt: 1 SilCam ROV Alt: 2 Dispersant delivery from surface/vessel Rising oil & gas plume Dispersant injection wand Dispersant Flow regulator OSSRL "Dispersant manifoil" SINTEF SilCam is to used to: 1. Monitor SSDI Effectiveness 2. Optimize dispersant dosage

27 What is the Technology Readiness level (TRL) for the SSDI injection system? An industry program "motivated" by the Norwegian authorities

28 An Oceaneering & SINTEF technology project Testing Oceaneering dispersant wands (down-scaled). Full-scale testing at dock-side (no oil & dispersants). Should be tested as a part of a future full-scale deep water field trial.

29 Screening SSDI effectiveness How to document that you are stockpiling the best dispersant..?

30 Relative Volume Distribution Bench-scale screening of dispersants for SSDI 16,0 14,0 12,0 oil only 1:1000 1:500 1:250 1% injection 1:100 10,0 1:50 8,0 6,0 4,0 2,0 0, ,2 74,7 63,3 53,7 45,5 38,5 32,7 27,7 23,5 19,9 16,8 14,3 12,1 10,2 8,69 7,36 6,24 5,29 Droplet size (µm) SINTEF MiniTower experiments with different DORs (Simulated Insertion Tool - SIT)

31 Relative shift in Mean Volume Diameter (-) Dispersant SSDI screening Skarfjell (Wintershall) Paraffinic crude 0,0 0,1 0,2 0,3 Corexit 9500 Dasic NS Finasol OSR 52 Superdispersant 25 0,4 0,5 0,6 0,7 0,8 0,9 1,0 oil only 1:1000 1:500 1:250 1:100 1:50 Dispersant to oil ratio SINTEF MiniTower testing (0.5 mm nozzle, 100 ml/min & simulated injection tool)

32 Dispersant effectiveness (IFP%) Relative shift in Mean Volume Diameter (-) Dispersant effectiveness (IFP%) Screening - SSDI vs. Surface application 0,0 0,1 0,2 0,3 Corexit 9500 Dasic NS Finasol OSR 52 Superdispersant 25 Paraffinic Dispersant effectiveness (IFP%) 0,4 60 0,5 50 0,6 0,7 0, ,9 1,0 oil only 1:1000 1:500 1:250 1:100 1:50 Dispersant to oil ratio 0 Corexit 9500 Dasic NS Finasol OSR-52 Finasol OSR-62 Superdispersant 25 Dispersant products Asphaltenic Dispersant effectiveness (IFP%) Corexit 9500 Dasic NS Finasol OSR-52 Finasol OSR-62 Superdispersant 25 Dispersant products

33 Summary SSDI R&D research Status: Modified Weber Scaling is well theoretical funded and extensively calibrated (small-field scale, gas, live oil.). Dispersant injection methods important (lab & field). Depth/pressure not a significant challenge (effectiveness!) What could/should be done more: Representative & relevant NEBA studies Documentation of dispersant effectiveness (SSDI) Verification of injection systems (increase TRLs..?) How to control the needed dispersant dosage? Monitoring capability central for control & documentation A verifying deep water field experiment is needed!