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APPENDIX A Questionnaire to Pipeline Operators on Transporting Diluted Bitumen The following questions were developed by the committee and given to the Canadian Energy Pipeline Association (CEPA) in January 2013. CEPA dis- tributed the questionnaire to member pipeline companies and returned the results in March 2013. Operator responses are indicated in bold text.1 â1. Please provide the following information: a. Total amount of transmission crude oil pipeline mileage: Approx- imately 24,000 b. Mileage dedicated to dilbit service: Approximately 890 c. Mileage in batch service: Approximately 20,530 d. Percentage of barrels transported per day consisting of diluted bitumen: Operator A: 82 percent Operator B: 15 to 65 percent Operator C: 65 percent Operator D: 65 percent Operator E: 28 percent dilbit; 3 percent synbit â2. Please provide the following parameters on the properties of diluted bitumen measured at points of custody transfer or in-line (as appro- priate and available): Table A-1 includes information gathered on a best-effort basis. One operator also reported some data for synbit, and these data were included for reference. In addition, H2S data for a large number of crude oils are available from a âAPI = American Petroleum Institute; CO2 = carbon dioxide; H2S = hydrogen sulfide; KOH = 1 potassium hydroxide; O2 = oxygen; ppm = parts per million; ppmw = parts per million by weight; psi = pounds per square inch; TAN = total acid number. 108
Questionnaire to Pipeline Operators 109 table a-1 Operator Responses to Question 2 Parameter Operator Average Normal Range Extreme High Total BS&W A 0.35 0.25â0.40 0.5 (volume percentage) B 0.21 0.05â0.36 0.36 C 0.18 0.11â0.25 0.5 D 0.26 0.05â0.5 0.5 E (dilbit) 0.28 0.1â0.38 0.5 E (synbit) 0.31 0.28â0.34 0.5 Water share of C 50 40â60 100 BS&W (%) Sediment share of C 50 40â60 100 BS&W (%) Solid content B 0â0.01 (ppmw) Solids particle Not routinely measured in crude oil size (Âµm) H2S (ppmw) B 6.77 0.1â11.1 11.1 C <0.5 10 E <0.5 <0.5 Carbon dioxide (ppm) Not routinely measured in crude oil Oxygen (ppm) Not routinely measured in crude oil Sulfur (weight A 3.8 3.62â3.85 percentage) B 3.3 2.45â4.76 4.8 C 3.8 3.79â3.89 4.0 D 3.7 3.0â4.1 4.1 E (dilbit) 4.0 3.46â4.97 5.2 E (synbit) 3.1 3.04â3.21 3.5 API gravity A 21.5 19.0â23.1 B 20.6 19.3â21.3 C 22.1 21.4â22.2 D 21 19.0â23.3 E (dilbit) 21.5 20.3â21.9 E (synbit) 19.8 19.5â20.1 Reid vapor pressure B 5.1 2.54â7.58 7.58 (psi) C 7 D 8 3â11.8 11.8 E (dilbit) 7.3 5.85â7.79 14.9 E (synbit) 3.1 2.4â3.0 14.9 (continued on next page)
110 Effects of Diluted Bitumen on Crude Oil Transmission Pipelines Operator Responses to Question 2 table a-1 Operator Responses to Question 2 (continued) Parameter Operator Average Normal Range Extreme High TAN (mg KOH/g) A 1 0.85â1.05 B 1.6 1.0â2.17 3.34 C 1.6 1.52â1.64 1.82 D 1.06 0.6â1.9 1.9 E (dilbit) 1.3 0.92â2.49 3.75 E (synbit) 1.6 1.4â2.22 2.5 Transport tempera- A 30 26â34 40 ture (Â°C), transmis- B 10 (winter); 4â29 32 sion pipelines 22 (summer) C 15 5â35 50 D 27 13â43 43 E 17 9.5â22.7 25.4 Flow rate (ft/s) A 4 2.0â6.0 in transmission B 6.56 4.5â7.2 8.2 pipelines C 2.5 0.5â4.7 5.0 D 6.7 4.8â8.2 8.2 E 3.63 3.63 4.04 Pressure (psi) A 930 700â1,200 1,300 in transmission B 600 43.5â1,160 1,440 pipelines C 500 175â1,350 1,440 D 430 50â1,440 1,440 E 750 750 1,095 study performed by Omnicon supported by several pipeline operators. These data were collected by using ASTM D5263 and have been included below for reference (see FigureÂ A-1). â3. How often (e.g., percentage of barrels transported) is specified basic water and sediment (BS&W) exceeded at diluted bitumen initial custody transfer? For dilbit batches, between 0 and 0.6 percent of the barrels transported exceeded specified limits. â4. Is BS&W exceeded more often for diluted bitumen compared with other crude oils transported? Three operators reported no differences. In two cases, dilbit batches did exceed specified limits more often than other crude oils by a small margin of between 0.1 and 0.3 percent.
Questionnaire to Pipeline Operators 111 FIGURE A-1 Supplemental information on H2S content. Note: H2S in crude, measured in liquid phase (ASTM D5263). â5. Do tank storage methods for diluted bitumen differ from those of other crudes to possibly affect level of O2, CO2, water, and other contaminants? No, the storage method is the same as for all crude oil com- modities. Dilbits are generally stored in their own commod- ity group to reduce downgrading. â6. Note any differences in set points for safety and control instrumen- tation for pipelines in diluted bitumen service as opposed to lines in other service: There are no differences. Standards and procedures are in place for control that are generic for all crude oil commodi- ties shipped. The standards and procedures are structured to ensure safe operation regardless of the commodity.
112 Effects of Diluted Bitumen on Crude Oil Transmission Pipelines â7. Note any differences in the frequency of shutdowns, low-flow, and non-turbulent flow conditions while in diluted bitumen service: There are typically no differences that are related to dilbit service. One operator reported a small increase of shutdown frequency due to BS&W exceedance. â8. Note any special surge control equipment and/or vibration moni- tors on pipelines that carry diluted bitumen: No special equipment has been installed specifically to accommodate dilbit. â9. Are drag-reducing agents used for diluted bitumen transportation? If so, does their use differ (more or less?) compared with other crude types? Three of five operators are currently not using drag-reducing agents for dilbit transportation. The use of drag-reducing agents is not specific to dilbit transportation. Their use is based on the operational requirements of a particular pipe- line segment and throughput required. 10. Do pipelines undergo more pressure cycling when in diluted bitu- men service? The operating philosophy and function of a pipeline drive pressure cycling, not the type of product transported. Batching between heavy and light products in the same pipeline may cause additional cycling; however, this is related to the switch in products rather than the prod- ucts themselves. One operator reported that dilbit ser- vice lines cycle less frequently than those in conventional crude oil service. 11. Are pressure cycles measured and monitored for use in fatigue calculations? Three of five operators currently monitor and use pressure cycles in fatigue calculations, and one operator is planning to complete this activity in the future. One operator does not currently complete this activity.
Questionnaire to Pipeline Operators 113 12. Are corrosion inhibitors, including biocides, used for diluted bitu- men shipments? If so, do quantities differ from those used for other crude types? Three of the operators use chemical treatment for bacte- ria or corrosion control in at least some of their pipelines. Chemical treatment requirement is determined by the flow conditions and pipeline condition. When such treatments are required, the volume and quantities are the same as for other crude oil pipelines. 13. Is cleaning required at different intervals for pipelines in diluted bitumen service versus pipelines in other service? The requirement for a cleaning program and cleaning inter- vals are primarily determined by consideration of flow con- ditions and the potential for water and sediment deposition for all crude oil types. No differences in cleaning intervals were reported by any operator. 14. Is the debris from pig cleaning analyzed? If so, note any differences in composition for pipelines in diluted bitumen service? Four of five operators complete testing of debris from pig cleaning, and no differences in composition have been reported for pipelines in dilbit service versus other heavy commodity pipelines. For pipelines in batch service with multiple products including dilbit, it is not possible to dif- ferentiate the sediment collected. 15. Is there any evidence from in-line inspection and/or other corro- sion monitoring activities indicating unusual or unexpected corro- sion locations for lines in diluted bitumen service? Corrosion in heavy-oil pipelines can occur in areas where water or sediment accumulatesâincluding low areas, critical inclines, and overbends. The latter location was unÂ xpected e when it was identified in 2005, but this does not appear to be unique to dilbit pipelines and is common to heavy commodi- ties in general. No unusual or unexpected corrosion loca- tions have been attributed to dilbit service.
114 Effects of Diluted Bitumen on Crude Oil Transmission Pipelines 16. Note any difference in clogging or wear of equipment, such as pumps, for lines in diluted bitumen service: No clogging or unusual wear has been identified for lines in dilbit service. 17. Note any differences in predictive/preventive maintenance prac- tices for lines in dilbit service: No special predictive or preventive maintenance practices are required for dilbit pipelines. 18. More generally, do you have integrity management programs spe- cific to lines in dilbit service? No, dilbit lines are incorporated into overall integrity man- agement programs. In more than 25 years of diluted bitumen service on some pipelines, no unique or more severe threats specific to diluted bitumen service have been observed.