1 Crude Preheat Management for Challenged and Unconventional Crudes COQA Meeting San Antonio 7 th March 2013 Greg Savage
Increased Fouling Potential From New Crudes 2
3 Energy Management and Fouling Control Overview Fouling problem solving: Evaluate mechanical, operational, and chemical root causes Identify fouling mechanism Select solution Monitor Performance
Observed Fouling Locations in the Crude Unit LOCATION Crude Preheat Exchangers Crude or Vacuum Furnace Gas Oil Loop Resid Exchangers Tower Tray / Packing Asphaltenes Corrosion Inorganic salts Polymer gum Coking
5 MOC Mechanical Operational Chemical Causes WHAT CAUSES FOULING?
6 Mechanical & Operational Causes Poor tank farm practices Incompatible Crude blending Slops containing ash, gums, coke, etc. High skin temperatures or heat fluxes High solids level in crude Poor desalting Other possible causes Low exchanger velocities Chemical additive treatment
Common Fouling Mechanisms Crude Preheats Unconventional Crudes 7 Deposit Asphaltenes Inorganic Solids Polymeric gum Coke Inorganic salts Cause Destabilization of asphaltenes High solids level in unconventional crudes Co-processing reactive streams or chemical additive treatment Dehydrogenation of asphaltenes & PNA s Poor or no desalting, amines
8 MOC HOW DO WE FIND THE ROOT CAUSE?
Root Cause Analysis: Fouling Mechanism 9 Deposit analysis Identify and quantify elemental components Interpret organic and inorganic nature Stream characterization Identify and quantify fouling precursors Fouling simulation and Chemical selection Simulate process fouling (mechanisms) Screen chemicals Together help describe probable fouling mechanisms MOC
10 Deposit Analysis Summary Analysis 80% Eagle Ford 25% Canadian 75% Domestic light Organic Materials 11.0% 95.2% Soluble Organics 5.0% 31% Coke, polymers 6.0% 64.2% Inorganic Materials 89.7% 4% Iron Salts: 40.6% 2.4% Other Salts including Volatile Salts: 49.1% 1.6% Carbon/Hydrogen Mass Ratio 10.0 11.2
11 Bakken Stream Analysis The Bakken Crude is Low in Asphaltenes and Metals High Solid Nos. Low in Aromatics Highly Paraffinic ANALYSIS Al Cu / Fe Ni / V Na / K Ca Mg Solids Acid No. Naphthenic Acid Asphaltenes Aromatic Paraffin Polar Aromatic (NMR) Flashed Crude Oil 0.3 ppm 0.06 / 4.1 ppm 0.61 / 0.22 ppm 4.1 / < 0.2 ppm 0.6 ppm < 0.2 ppm 39 lbs / Mbbls 0.07 mg KOH/g < 0.1 mg KOH/g 0.1 wt% 8.8 wt% 37 wt% 1.4 wt% 14.6 mole%
12 75% Eagle Ford Stream Analysis High solids level made up of inorganic material Analysis Filtered Total Al 0.17 ppm 4.9 ppm Ca 1.4 ppm 15 ppm Cu / Fe 0.16 / 3 ppm 0.21 / 16 ppm Mg < 0.12 ppm 1.6 ppm Ni / V 8 / 22 ppm 8 / 22 ppm Na / K 0.4 / < 0.3 ppm 34 / 1.2 ppm Cl Solids 59 ppm 150 lbs/mbbls Water 0.2 vol % BS&W 0.4 vol %
Laboratory Furnace Fouling Simulation 13 HLPS Test Equipment Bakken fouling
14 Characterization Of Deposit From HLPS Analysis Wt % Fe 18.0 S 17.0 Ca 0.5 C 51.0 H 5.0 N 0.8 Left to Right: Blank, Products A, B, C, D Elemental Maps Iron = red, Sulfur = green, Phosphorus = blue
12 10 8 6 4 2 0 0 8 10 12 14 16 18 20 15 Crude Stability Index (CSI) 20+ years Commencement of Solvent Addition Solvent Dilution Solvent Dilution Flocculation Point Volume of Aliphatic Solvent
Component and Blend CSI indicating Potential Incompatibility
Crude Stability Determination: Blends 28.6 Unconventional blend with few asphaltenes 44.5 22.6 CSI
Assessment of Shale Condensate on Crude Stability Identify blend instability region 100 90 80 Crude Stability Index 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Percentage of WCS in Bakken
Stability Change with Process Temperature
Asphaltene Dispersant Performance using CSI
Intrinsic Stability Analyzer Intrinsic stability S concept as per ASTM D 7157 Simple to operate, user friendly Results obtained in about 20 minutes S = Stability So = Solvency Power of Oil Sa = Asphaltene Solubility
Blending Order Stability Study?
23 Fouling Control Strategies Do nothing Mechanical options Operational options Evaluate chemical solution(s) Understand mechanistic function of products Improved monitoring Field support tools
Tracking treatment performance Midcontinent Domestic with Canadian
25 Tracking treatment performance
26 Acknowledgements Gregg McAteer Laura Copeland Sam Lordo Keith Gawrys Christopher Russell Michael Braden John Garcia Kailash Sawhney Disclaimer: The contents of this document are, to the best of our knowledge, accurate at the date of publication. We shall not be liable for any loss or damage whatsoever resulting from reliance on its contents. All warranties as to fitness for purpose or otherwise (howsoever made or implied) in respect of this publication are excluded.
Questions 27