Application of novel hydrophobically modified polybetaines based on alkylaminocrotonates and methacrylic acid as pour point depressants and ASP flooding agent

A series of hydrophobically modified polymeric betaines (HMPB) were synthesized from alkylaminocrotonates and methacrylic acid, analyzed by methods of GPC, potentiometric titration and DSC and applied as pour point depressants (PPD) to high paraffinic crude oils of Western Kazakhstan. The efficiency of paraffin inhibition with the help of HMPB was evaluated in static and dynamic conditions. The physicochemical properties of the Mangyshlak oil and the Buzachi–Mangyshlak oil mixture (67:33 vol%) were determined. Paraffins were found to form gelled networks in the Mangyshlak oil and Buzachi–Mangyshlak oil mixture within the fractions of hydrocarbons with lengths of C 12 –C 17 and C 13 –C 16 . The results of testing the HMPB as PPD in the model tank and oil pipeline showed that, at a concentration of polymeric additives of 500 ppm and at an injection temperature of 60 °C, the quantity of precipitated asphaltene–resin–paraffin depositions was significantly reduced. The efficiency of HMPB bearing C 16 H 33 groups was tested as a prototype alkaline–surfactant–polymer flooding agent on the heavy oil of the Karazhanbas oilfield.