Enbridge System and Commodities. Ashok Anand Director, Petroleum Quality October 9th 2012

Transcription

1 Enbridge System and Commodities Ashok Anand Director, Petroleum Quality October 9th 2012

2 Enbridge Liquids Pipelines History and System Information Began operation in 1950 s ~ 2.2 MMbpd (2012) > 15,000 miles of pipe ~ 400,000 mile-years experience in crude service 1955 first heavy oils moved 1 st oilsand synthetic in 1968 Topped 100kbpd dilbit 1986 Dilbit volumes increasing Enbridge expects to continue being a major carrier of oil sands products in the future 2

3 Enbridge Mainline Schematic Overall Tariff Specifications Temperature <38 deg C RVP < 103 kpa S&W <= 0.5% Density < 940kg/m3 or 19 API Viscosity < 350cSt 3

4 Enbridge Crude Types Group ID Crude Name Group ID Crude Name Heavy AHS Albian Heavy Synthetic Medium M Midale Blend ARB Albian Resid Blend BR Bow River High Sour MJT Moose Jaw Tops CL Cold Lake SHE Sour Heavy Edmonton F Fosterton SO Mixed Blend Sour LLB Lloydminster Hardisty Light Sour LSB Light Sour Blend LLK Lloydminster Kerrobert BSO BP Caven Sweet/Sour SC Smiley Coleville Heavy SLE Sour Light Edmonton WCB Western Canadian Blend Sweet SW Mixed Blend Sweet WCS Western Canadian Select UHC U.S. Sweet WH Wabasca Heavy Light Synthetic CNS CNRL Synthetic Blend Heavy Low Resid AVB Albian Vacuum Gas Oil Blend HSB Husky Synthetic Blend *OSH Suncor H NSA Newgrade Synthetic Blend Heavy High TAN Dil-Bit AMH Albian Muskeg River Heavy *OSA Suncor-A AWB Access Heavy Blend OSC Suncor-C *BHB Borealis Heavy Blend PAS Premium Albian Synthetic *CDB Cenovus Christina Lake Dil-Bit *PSC Long Lake Synthetic Blend PH Peace Heavy SPX Shell Synthetic *SCB Statoil Cheecham Blend SSX Shell Synthetic Light SH Seal Heavy *SYN Syncrude Heavy High TAN Syn-bit *CSB Christina Lake Syn-Bit Condensate CRW Condensate Blend *MKH MacKay River Heavy *OSN Suncor - N *PSH Long Lake Heavy Blend *SHB Surmont Heavy Blend Caroline Condensate CCA Caroline Condensate Cracked Crude *OCC Suncor Cracked C OSJ Suncor - J *OSS Suncor S Sarnia Special SSS Sarnia Special Blend PBS Pine Bend Special * Commodity moves on Athabasca System 5

5 The Quality Matrix Number & Type Some crude properties limit use by some refineries: Eg. TAN, total sulphur, olefins, heavy Enbridge monitors the quality of products at both injection and delivery locations (custody transfer points) Operations are optimized to limit mixing of incompatible crudes CRUDE TYPE MATRIX - THE QUALITY PROCESS Heavy -TAN Heavy Medium Sour Sweet Synthetic Condensate Heavy -TAN Heavy Medium Sour Sweet Synthetic Condensate The above numbers rank the order (as a guideline) that should be follow ed w hen changing from crude types. One being first choice. Seven being the last choice. When making sequence decisions betw een crudes of the same type(heavy-heavy).reference the crude prices for best choice. 5 5

6 Activities to maintain crude quality Enbridge controls quality of delivered crude in the following ways. In the Pipe: Manage Interface - number, type, size, cut Line Splits: Like Commodities in segregated lines Line Rates: Turbulent flow to minimize interface sizes Batch Pigs: In laminar flow lines to minimize interface sizes Batch Sizes: Minimum 60KB, Multiples batch trains Batch Sequence; Based on least contamination risk Batch Cuts (Interfaces): Mid point based on density In the Tank Tank Bottoms Crossing Tank Selection Tank Service Change 6 6

7 Corrosivity Considerations Corrosivity of crude is very low (dil-bit included) Enbridge experience shows heavy oils are more likely to present internal corrosion than other crude types Sediment consideration incorporated into PRCI ICDA report (2005) Review of corroded locations indicated sediment deposition at unexpected locations (overbends) Enbridge has been working with industry leaders to develop better models In-house susceptibility model based on NACE SP0208 precepts Model considers water transport as surrogate for solids transport Incorporates viscosity, density, diameter, S&W and velocity Chemical/bacterial factors are all conservatively assumed present Enbridge is collaborating with many industry partners: AITF, CanMet, GE Water and Process Technology, Champion Chemicals, Broadsword Engineering, and very involved in NACE, PRCI, IPC, and ASME Developing ASTM G205 towards standard classification Working on NACE TM0172 adaptation for uninhibited products Working on sediment transportation models 7

8 Corrosivity Considerations Corrosion is a function of corrosivity and exposure duration Enbridge experience indicates exposure is far more significant than relative corrosivity (virtually all crudes are inhibitory) Work by Battelle: comparing TAN, S, sediment, and salt to WTI is arbitrary and could potentially misdirect effort from more important factors: Every complex problem has at least one simple, INCORRECT solution Effort must be allocated appropriately (exposure/corrosivity) Slight variations in corrosivity are expected to provide slight augmentation to exposure based susceptibility models Variation in corrosion rate is exactly what effective, mature integrity management programs are intended to manage Effective integrity management = safe pipe 8

9 Enbridge Corrosion Model Development Original model subjective operations review All factors being equal, past performance is best indicator of future performance Qualitative analysis Procedure was adapted through the use of relevant metrics Annualized flow, product spectrum, prior internal corrosion indications Consideration of potential non-hydrocarbon components broadly considered Semi-quantitative analysis (quantitative factors considered qualitatively) Current iteration uses actual hourly SCADA operational data Leverage what we know: Water accumulation models are well established Sediment models are less well understood We have a wealth of operational experience to draw upon Continue exploration of sediment deposition models Engaged CFD modeling experts and try to demonstrate and support what we know to be true (based on operational experience) Use water transport models as surrogate for solids 9

10 Example analysis - Provides quantitative assessment of water holdup - Can be used (consistently) as surrogate for solids - Considers effect of high Froude flow (fluid pigging) 10

11 Future Modeling Developments 10X reduction in near wall velocity in heavy products vs. light, exacerbated by overbends. This explains majority of Enbridge internal corrosion experience. 11

12 Internal Corrosion Management Internal Corrosion Control Process Safety: minimize amount of potential corrodents (Enbridge s limit is 0.5% by volume). Transmission quality crudes generally non-corrosive. Modeling: Assess susceptibility for corrosion to occur (flowrate, temperature, product density). Majority of Enbridge research is aimed at accumulation models (sediment) Enbridge also developing corrosion test methods Mitigation: Use regular cleaning and/or inhibition on pipelines identified as susceptible to water or solids accumulation Monitoring: Strategic use of ILI to evaluate pipe condition prior to integrity threats. All pipelines in mainline system are smart piggable Frequency of ILI is segment specific Use continuous monitors where additional information is desired, where practical Use combination (alternating) inspection technologies to offset limitations of any single technology Maintain: Perform repairs as required to maintain pipeline fitness for purpose. Demonstrated effectiveness: Enbridge has never had an in-service internal corrosion release on it s piggable mainline system (three possible releases, less than 11 bbls total volume spilt). 12