Optimization of Preparation of Amphiphilic Polymer as High Temperature Retarder and Intelligent Control of Thickening Time of Cement Slurry by Response Surface Methodology

Cementing in long sealing section of deep well is faced with the problem of long thickening time in high temperature section and long solidification time in low temperature section. Based on the concept of molecular structure activity changes during the formation/dissociation of amphiphilic polymer self-assembly structure. AMPS, unsaturated carboxylic acid (PA) and cationic monomer (CM) are used to synthesis a temperature responsive intelligent retarder TRIR by RAFT polymerization. Response surface methodology was used to optimize the synthetic process conditions of the polymer. The optimal process conditions were determined as follows: monomer concentration 28.7%, initiator dosage 0.6%, synthesis temperature 50 ℃, and reaction pH 4.5. The structure and thermal stability of the polymer were characterized by infrared spectroscopy and thermogravimetric analysis, and its retarding performance was evaluated. The results show that TRIR has excellent temperature resistance, the thickening time at 200 ℃ can reach 356 min under 4.0% (liquid) dosage, and the retarding property is significantly enhanced with the temperature rise in the range of 120～180 ℃. The thermal response polymer proposed in this paper can provide a new idea for the development of intelligent polymer in the future petrochemical field.