Inhibition Of Barite Scale In The Presence Of Hydrate Inhibitors
- Mason B. Tomson (Rice U.) | Amy T. Kan (Rice U.) | Gongmin Fu (Rice U.)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- September 2005
- Document Type
- Journal Paper
- 256 - 266
- 2005. Society of Petroleum Engineers
- 4.2.3 Materials and Corrosion, 4.1.2 Separation and Treating, 4.3.1 Hydrates, 6.5.4 Naturally Occurring Radioactive Materials, 4.3.4 Scale
- 0 in the last 30 days
- 509 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
Large volumes of hydrate inhibitors [e.g., methanol, ethanol, monoethyleneglycol (MEG), and triethylene glycol (TEG) as cosolvent] are added to controlhydrate formation. Such practice has an adverse effect on scale formationbecause the mineral salts are generally less soluble in the cosolvent. Becauseof production from reservoirs, oilfield brines are often close to saturation asthey enter a well; even a small amount of added methanol, ethanol, and so on isoften sufficient to induce various minerals to precipitate, particularly thesparingly soluble minerals (e.g., barite). For example, barite solubility isreduced by as much as 20-fold with 50 wt% methanol.
In this paper, barite nucleation rates were studied over a wide range ofconcentrations, such as Ba2+ (0.5 to 1.8 mm) SO42- (0.5 to 1.8 mm) methanol (0to 40 wt%), MEG (0 to 40 wt%) or TEG (40 wt%). Barite nucleation rate issignificantly accelerated in as little as 5wt% methanol. The barite nucleationrate can be modeled with an equation modified from the classical nucleationtheory in this study. The inhibition of barite by two phosphonate inhibitorsand a polymer inhibitor in the cosolvent/brine solution is more complex. Atlower cosolvent concentrations (<30 wt%), the nucleation inhibition can bepredicted with a previously derived semi-empirical model that mathematicallyseparates the effect of added inhibitors from that of the uninhibited mineralphase. At high methanol (>30 wt%) concentration, barite nucleation may bedifficult to inhibit by scale inhibitors because of high supersaturation andthe tendency of phosphonate to be precipitated as metal salt.
Barium sulfate, BaSO4 scale, is commonly found in oil and gas wells andvarious industrial water treatment systems.It is problematic becauseBaSO4 is difficult to remove once formed.Furthermore, it is oftenenriched with radium as the result of coprecipitation.Therefore, thestudy of precipitation of BaSO4 from supersaturated solution is of bothscientific and practical importance.
|File Size||2 MB||Number of Pages||11|
1. He, S., Oddo, J.E., and Tomson, M.B.: "The nucleation kinetics ofbarium sulfate in NaCl solutions up to 6m and 90°C ," Journal of Colloidand Interface Science (1995) 174, 319.
2. Wojciechowski, K. and Kibalczyc, W.: "Light Scattering Study ofKH2PO4 and BaSO4 Nucleation Process," Journal of Crystal Growth (1986) 76,379.
3. Hartman, P. and Strom, C.S.: "Structural Morphology ofCrystals With the Barite (BaSO4) Structure: A Revision and Extension,"Journal of Crystal Growth (1989) 97, 502.
4. Allan, N.L. et al.: "Calculated Bulk and Surface Properties of Sulfates,"Faraday Discuss.(1993) 95, 273.
5. Liu, S.T. and Nancollas, G.H.: "Scanning ElectronMicroscopic and Kinetic Studies of the Crystallization and Dissolution ofBarium Sulfate Crystals," Journal of Crystal Growth (1976) 33, 11.
6. Kan, A.T., Fu, G., and Tomson, M.B.: "Effect of methanol on carbonateequilibrium and calcite solubility in a gas/methanol/water/salt mixedsystem," Langmuir (2002) 18, 9713.
7. Kan, A.T., Fu, G., and Tomson, M.B.: "Effect of methanol and ethyleneglycol on sulfates and halite scale formation ," Ind. Eng. Chem. Res.(2003) 42, 2399.
8. Kan, A.T. et al.: "Effect ofHydrate Inhibitors on Oilfield Scale Formation and Inhibition," paper SPE74657 presented at the 2002 SPE International Symposium on Oilfield Scale,Aberdeen, 30-31 January.
9. Nikitina, L.V., Grigor'ev, A.I., and Dyatlova, N.M.: "Acid dissociationof nitrilotrimethylphosphonic acid," J. Gen. Chem. USSR (1974) 44.
10. Tikhonova, L.I.: "Complex Formation by Diethylenetriamine -NNN'N'-penta(methylphosphonic) Acid," Russ. J. of Inorg. Chem. (1968) 13, 1384.
11. Tomson, M.B., Kan, A.T., and Oddo, J.E.: "The acid/base and metal complexsolution chemistry of the polyphosphonate, DTPMP versus temperature and ionicstrength," Langmuir (1994) 10, 1442.
12. Xiao, J., Kan, A.T., and Tomson, M.B.: "The acid-base and metal-complexationchemistry of phosphino-polycarboxylic acid under high ionic strength and hightemperature," Langmuir (2001) 17, 4661.
13. Tanford, C.: Physical Chemistry of Macromolecules, John Wiley and Sons,New York City (1967).
14. He, S., Kan, A.T., and Tomson, M.B.: Water Soluble Polymers: SolutionProperties and Applications, Z. Amjad (ed.), Plenum Press, New York City (1997)163-170.
15. He, S.L., Kan, A.T., and Tomson, M.B.: "Mathematical Inhibitor Model forBarium Sulfate Scale Control," Langmuir (1996) 12, 1901.
16. He, S.L. et al.: "A NewInteractive Software for Scale Prediction, Control, and Management," paperSPE 38801 presented at the 1997 SPE Annual Technical Conference and Exhibition,San Antonio, Texas, 5-8 October.
17. He, S.L., Kan, A.T., and Tomson, M.B.: "Inhibition of calciumcarbonate precipitation in NaCl brines from 25 to 90°C ," AppliedGeochemistry (1999) 14, 17.
18. Xiao, J.A., Kan, A.T., and Tomson, M.B.: "Prediction of BaSO4 precipitation inthe presence and absence of a polymeric inhibitor: Phosphino-polycarboxylicacid," Langmuir (2001) 17, 4668.
19. Söhnel, O. and Mullin, J.W.: "Interpretation ofCrystallization Induction Periods," J. Colloid Interface Sci. (1988) 123,43.
20. Eaton, A.D., Clesceri, L.S., and Greenberg, A.E.: Standard Methods forthe Examination of Water and Wastewater, APHA, AWWA, and WPCF, Washington, DC(1998).