The Use of PPCA in Scale-Inhibitor Precipitation Squeezes: Solubility, Inhibition Efficiency, and Molecular-Weight Effects
- Nazia M. Farooqui (Heriot-Watt University) | Ken S. Sorbie (Heriot-Watt University)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- August 2016
- Document Type
- Journal Paper
- 258 - 269
- 2016.Society of Petroleum Engineers
- Ca_PPCA precipitate complex, Molecular Weight Distribution, PPCA, Precipitate polymer model, Polymeric Scale inhibitor
- 1 in the last 30 days
- 238 since 2007
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Phosphino polycarboxylic acid (PPCA) is an industry standard polymeric scale inhibitor (SI) that is often applied as a precipitation-squeeze treatment. In this phase-separated process, PPCA forms a sparingly soluble complex with calcium ions. We show that the solubility of the precipitated complex is rather different than the stock (“as supplied”) PPCA. We examined important properties such as its inhibition efficiency (IE) and its response in assay [by inductively coupled plasma (ICP) spectroscopy or wet-chemical methods], which are all understood in terms of the molecular-weight distributions (MWDs) of the various species involved in the precipitation squeeze.
Our findings on the MWD effects have relevance not just in determining the concentration of the polymer in the return curve (PPCA), but also in its ability to prevent scale formation (i.e., its IE in the PPCA return curve), and they have implications for how the process should be modeled correctly. We study the MWDs of PPCA in great detail along with the solubility behavior of the PPCA_Ca complex, which plays an important role in precipitation-squeeze treatments. We describe several novel findings on the solubility of the (PPCA_Ca) complex system. Specifically, the precipitated complex was isolated and its solubility was determined experimentally in various brine compositions and as a function of temperature. MWDs were determined for the various fractions of PPCA. The solubility of the precipitated PPCA_Ca complex becomes lower as it is exposed to successive fresh supernatant brine, and the behavior is very unlike that expected from a “solubility product” model. However, by being able to carry out MWD experiments on the various PPCA species, a fairly complete understanding is being generated. This has led to the proposal of the “stripping” model of dissolution for the precipitated complex of PPCA.
We believe that these results are the most detailed to be published in the literature on the PPCA system and that they are of particular significance and application for all polymeric SI precipitation-squeeze treatments. The relevance of these results for field precipitation-squeeze treatments is also discussed.
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Amjad, Z. and Masler, W. 1985. The Inhibition of Calcium Sulfate Dihydrate Crystal Growth by Polyacrylates and the Influence of Molecular Weight. Presented at Corrosion 85, Boston, Massachusetts, USA, 25–29 March. NACE-85-357.
Andrei, M. and Malandrino, A. 2003. Comparative Coreflood Studies for Precipitation and Adsorption Squeeze with PPCA as the Scale Inhibitor. Petroleum Science and Technology 21 (7–8): 1295–1315. http://dx.doi.org/10.1081/LFT-120018174.
Boak, L. S. and Sorbie, K. S. 2010. New Developments in the Analysis of Scale Inhibitors. SPE Prod & Oper 25 (4): 533–544. SPE-130401-PA. http://dx.doi.org/10.2118/130401-PA.
Breen, P. J., Diel, B. N., and Downs, H. H. 1990. Correlation of Scale Inhibitor With Adsorption Thermodynamics and Performance in Inhibition of Barium Sulfate in Low-pH Environments. Presented at the SPE Annual Technical Conference and Exhibition, New Orleans, 23–26 September. SPE-20688-MS. http://dx.doi.org/10.2118/20688-MS.
Browning, F. H. and Fogler, H. S. 1995. Precipitation and Dissolution of Calcium Phosphonates for the Enhancement of Squeeze Lifetimes. SPE Prod & Fac 10 (3): 144–150. SPE-25164-PA. http://dx.doi.org/10.2118/25164-PA.
Dubay, M. R. 2011. The Molecular Weight Effects of Poly(acrylic acid) on Calcium Carbonate Inhibition in the Kraft Pulping Process. PhD dissertation, University of Minesota.
Ebbing, D. D. and Wrighton, M. S. 1996. General Chemistry, fifth edition. Houghton Mifflin Company.
Farooqui, N. M. and Sorbie, K. S. 2013. Phase Behaviour of Polyphosphino Carboxylic Acid (PPCA) Scale Inhibitor for Application in Precipitation Squeeze Treatments. Presented at RSC Conference–Chemistry in the Oil Industry XIII: Oilfield Chemistry–New Frontiers, Manchester, UK, 4–6 November.
Farooqui, N. M. and Sorbie, K. S. 2014. Oilfield Scale Inhibitors for Application in Precipitation Squeeze Treatments: Solubility of the Ca_PPCA Complex. Presented at the SPE International Oilfield Scale Cnference and Exhibition, Aberdeen, UK, 14–15 May. SPE-169792-MS. http://dx.doi.org/10.2118/169792-MS.
Farooqui, N. M., Sorbie, K. S., Grice, A., Haddleton, D. 2014. Polyphosphino Carboxylic Acid (PPCA) Scale Inhibitor for Application in Precipitation Squeeze Treatments: the Effect of Molecular Weight Distribution. Presented at CORROSION 2014, San Antonio, Texas, USA, 9–13 March. NACE-2014-4100.
Fleming, N., Bourne, H. M., Strachan, C. J. et al. 2001. Development of an Ecofriendly Scale Inhibitor for Harsh Scaling Environments. Presented at the SPE International Symposium on Oilfield Chemistry, Houston, 13–16 February. SPE-65040-MS. http://dx.doi.org/10.2118/65040-MS.
Graham, G. M., Boak, L. S., and Sorbie, K. S. 2003. The Influence of Formation Calcium and Magnesium on the Effectiveness of Generically Different Barium Sulphate Oilfield Scale Inhibitors. SPE Prod & Fac 18 (1): 28–44. SPE-81825-PA. http://dx.doi.org/10.2118/81825-PA.
Graham, G. M. and Sorbie, K. S. 1994. The Effect of Molecular Weight on the Adsorption/Desorption Characteristics of Polymeric Scale Inhibitors on Silica Sand and in Sandstone Cores. Presented at CORROSION 94. Baltimore, Maryland, USA, 28 February–4 March.
Graham, G. M. and Sorbie, K. S. 1995. Examination of the Change in Returning Molecular Weight Obtained During Inhibition Squeeze Treatments Using Polyacrylate Based Inhibitors. Presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, USA, 14–17 February. SPE-29000-MS. http://dx.doi.org/10.2118/29000-MS.
Hills, E. J., Graham, G. M., Langlois, B. et al. 2005. Molecular Weight and Compositional Controls on the Performance of Polymeric Scale Inhibitors–A mechanistic Interpretation. Proc., NIF 16th International Oilfield Chemicals Symposium, Geilo, Norway, 13–15 March.
Ibrahim, J. M., Sorbie, K. S., and Boak, L. B. 2012. Coupled Adsorption/Precipitation Experiments: 1. Static Results. Presented at the SPE International Conference on Oilfield Scale, Aberdeen, UK, 30–31 May. SPE-155109-MS. http://dx.doi.org/10.2118/155109-MS.
Jordan, M. M., Sorbie, K. S., Yuan, M. D. et al. 1995. Static and Dynamic Adsorption of Phosphonate and Polymeric Scale Inhibitors Onto Reservoir Core From Laboratory Tests to Field Application. Presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, USA, 14–17 February. SPE-29002-MS. http://dx.doi.org/10.2118/29002-MS.
Kahrwad, M., Sorbie, K. S., Boak, L. S. 2008. Coupled Adsorption/Precipitation Of Scale Inhibitors: Experimental Results and Modelling. Presented at the SPE International Oilfield Scale Conference, Aberdeen, UK, 28–29 May. SPE-114108-MS. http://dx.doi.org/10.2118/114108-MS.
Kelland, M. A. 2009. Production Chemicals for the Oil and Gas Industry. Boca Raton, Florida: CRC Press.
Malandrino, A., Yuan, M. D., Sorbie, K. S. et al. 1995. Mechansitic Study and Modelling of Precipitation Scale Inhibitor Squeeze Processes. Presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, USA, 14–17 February. SPE-29001-MS. http://dx.doi.org/10.2118/29001-MS.
Rabaioli, M. R. and Lockhart, T. P. 1995. Solubility and Phase Behaviour of Polyacrylate Scale Inhibitors and Their Implications for Precipitation Squeeze Treatment. Presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, USA, 14–17 February. SPE-28998-MS. http://dx.doi.org/10.2118/28998-MS.
Rabaioli, M. R. and Lockhart, T. P. 1996. Solubility and Phase Behaviour of Polyacrylate Scale Inhibitors. Journal of Petroleum Science and Engineering 15 (2–4): 115–126. http://dx.doi.org/10.1016/0920-4105(96)00008-3.
Shaw, S. S., Sorbie, K. S., Boak. L. S. 2012. The Effects of Barium Sulfate Saturation Ratio, Calcium, and Magnesium on the Inhibition Efficiency: Part II Polymeric Scale Inhibitors. SPE Prod. & Oper 27 (4): 390–403. SPE-130374-PA. http://dx.doi.org/10.2118/130374-PA.
Sorbie, K. S. 2012. A Simple Model of Precipitation Squeeze Treatments. Presented at the SPE International Conference on Oilfield Scale, Aberdeen, UK, 30–31 May. SPE-155111-MS. http://dx.doi.org/10.2118/155111-MS.