Stability of Biopolymer and Partially Hydrolyzed Polyacrylamide in Presence of H2S and Oxygen
- Mohammed Taha Al-Murayri (KOC) | Dawood Sulaiman Kamal (KOC) | Jose Gregorio Garcia (KOC) | Naser Al-Tameemi (KOC) | Jonathan Driver (UEORS) | Richard Hernandez (UEORS) | Robert Fortenberry (UEORS) | Christopher Britton (UEORS)
- Document ID
- Society of Petroleum Engineers
- SPE Annual Technical Conference and Exhibition, 24-26 September, Dallas, Texas, USA
- Publication Date
- Document Type
- Conference Paper
- 2018. Society of Petroleum Engineers
- Biopolymer, Oxygen, H2S, Polymer Stability, Acrylamide
- 13 in the last 30 days
- 212 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 8.50|
|SPE Non-Member Price:||USD 25.00|
There are many oil reservoirs worldwide with substantial amount of H2S but otherwise very favorable conditions for polymer flooding such as low temperature, high permeability, and moderate to high oil viscosity. However, there is a legitimate concern about the chemical stability of polymers when there is dissolved oxygen in the injection water or injection facility and its high concentrations of H2S in the reservoir.
Several synthetic polymers and biopolymers were selected for stability testing under a wide range of conditions. We focused on identifying the concentration limits for co-presence of H2S and oxygen for which the synthetic and biopolymers are stable for an extended period, using different, widely available brine compositions. Experiments were conducted with and without standard polymer protection packages to evaluate their effects on stability and degradation under sour conditions. Viscosity of polymer solutions with varying concentrations of H2S and oxygen were measured and compared with the oxygen free or H2S free solution viscosities for a period of 6 months. Several methods of safely introducing H2S to the polymer solution were investigated and compared.
The laboratory results indicated that biopolymers were stable at all the concentrations of oxygen and H2S concentrations studied. Three synthetic polymers tested showed some degradation in the presence of oxygen and H2S but were stable when either species is absent. The results indicated that oxygen is the limiting reagent in the degradation reaction with partially hydrolyzed polyacrylamide (HPAM) polymers under normal reservoir conditions.
We observed little-to-no difference in degradation between samples with 10 or 100 ppm H2S at 500 ppb oxygen concentration, so H2S is not the limiting reagent under these conditions. Additionally, HPAM exposed to 10 ppm H2S and intermediate levels of oxygen (~0.5 ppm) only partially degrades, while samples exposed to H2S and ambient oxygen completely degrade. We anticipate these results will be useful for operators evaluating the potential of polymer flooding in sour reservoirs to follow a stricter polymer preparation at the surface facility to minimize oxygen concenration.
|File Size||1 MB||Number of Pages||10|
Burger, E. D., Jenneman, G. E., & Carroll, J. J. (2013, April 8). On the Partitioning of Hydrogen Sulfide in Oilfield Systems. Society of Petroleum Engineers. doi:10.2118/164067-MS
Davison, P., & Mentzer, E. (1982, June 1). Polymer Flooding in North Sea Reservoirs. Society of Petroleum Engineers. doi:10.2118/9300-PA
Jensen, T., Kadhum, M., Kozlowicz, B., Sumner, E. S., Malsam, J., Muhammed, F., & Ravikiran, R. (2018, April 14). Chemical EOR Under Harsh Conditions: Scleroglucan As A Viable Commercial Solution. Society of Petroleum Engineers. doi:10.2118/190216-MS
Jouenne, S., Klimenko, A., & Levitt, D. (2016, April 11). Polymer Flooding: Establishing Specifications for Dissolved Oxygen and Iron in Injection Water. Society of Petroleum Engineers. doi:10.2118/179614-MS
Levitt, D. B., Slaughter, W., Pope, G., & Jouenne, S. (2011, June 1). The Effect of Redox Potential and Metal Solubility on Oxidative Polymer Degradation. Society of Petroleum Engineers. doi:10.2118/129890-PA
Kalpakci, B., Arf, T. G., Barker, J. W., Krupa, A. S., Morgan, J. C., & Neira, R. D. (1990, January 1). The Low-Tension Polymer Flood Approach to Cost-Effective Chemical EOR. Society of Petroleum Engineers. doi:10.2118/20220-MS
Khorrami, P., & Radke, C. J. (1988, February 1). A Random Scission Model for Chemical Degradation of Polymer Solutions. Society of Petroleum Engineers. doi:10.2118/15197-PA
Ramsden, D.K. & McKay, K. (1986). The degradation of polyacrylamide in aqueous solution induced by chemically generated hydroxyl radicals: Part II—Autoxidation of Fe2+. Polymer Degradation and Stability. 15. 15–31. 10.1016/0141-3910(86)90003-0.
Seright, R. S., & Skjevrak, I. (2014, April 12). Effect of Dissolved Iron and Oxygen on Stability of HPAM Polymers. Society of Petroleum Engineers. doi:10.2118/169030-MS
Yang, S. H., & Treiber, L. E. (1985, January 1). Chemical Stability of Polyacrylamide Under Simulated Field Conditions. Society of Petroleum Engineers. doi:10.2118/14232-MS
Zentz, Frederic & Verchère, Jean-François & Muller, Guy. (1992). Thermal denaturation and degradation of schizophyllan. Carbohydrate Polymers. 17. 289–297. 10.1016/0144-8617(92)90172-M.