Heat-Exchanger Deposition in an Inverted Steam-Assisted Gravity Drainage Operation. Part 1. Inorganic and Organic Analyses of Deposit Samples
Bibliographic record
Abstract
Heat-exchanger fouling is a severe operational problem in steam-assisted gravity drainage (SAGD) processes. In an effort to better understand which species are prone to deposit and gain insights into means for mitigating SAGD heat-exchanger deposition, analyses were performed on a series of heat-exchanger deposit samples from an inverted SAGD operation in Canada. Deposit samples were obtained from each of five heat-exchanger banks used in the operation of the facility: exchangers heating the produced raw bitumen reverse emulsion coming from the wells (two exchanger banks in series) and exchangers cooling separated produced water leaving the high-temperature separator (HTS) (three exchanger banks in series). The separated produced water leaving the facility HTS was also analyzed. The analyses focused on determining the overall inorganic and organic elemental compositions, as well as providing general information on the type of chemical species predominately present. The analyses performed on the deposits and solids from the produced water included (1) carbon, hydrogen, and nitrogen analyses, (2) X-ray fluoresence, (3) X-ray diffraction, (4) thermogravimetric analyses, (5) chloroform/methanol/toluene solubilities, and (6) Fourier transform infrared spectroscopy. Ion chromatography and inductively coupled plasma analyses were also run on the water sample. Analyses indicated preferential deposition of particular species and potential causes of deposition in certain exchangers. For the SAGD operation, at that time, a periodic slop-tank recycle containing warm lime softener sludge was indicated as a source of a significant amount of fouling in the heat exchangers handling the produced bitumen reverse emulsion and the initial exchanger cooling separated produced water leaving the HTS. High Mg +2 and Si +4 compositions were detected in these deposits. Magnesium silicates were indicated in Fourier transform infrared spectroscopy analyses. Deposition of additional other sand/silicates was also indicated. For the organic portion of these deposits, significant concentrations of organic acids and organic acid salts were indicated within the deposit hydrocarbons. Although all deposits contained both inorganic and organic components, the deposits in the last two exchangers cooling the produced water were found to be predominately organic. Significant concentrations of organic acids and organic acid salts were also indicated in these deposits. The indications of a significant organic acid/acid salt content led to collaboration work with the National High Magnetic Field Laboratory to study these components in detail. Electrospray ionization Fourier transform ion cyclotron resonance mass spectroscopy work performed at the National High Magnetic Field Laboratory is discussed in the part 2 companion paper (Schaub, T. M.; Jennings, D. W.; Kim, S.; Rodgers, R. P.; Marshall, A. G. Energy Fuels 2007, 21, 185−194) of this series.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".