SYNTHESIS AND LABORATORY EVALUATION OF A TYPE OF THICKENER HAT-1 FOR HYDROPHOBIC ASSOCIATION FRACTURING FLUID

摘要

Based on aqueous solution polymerisation, a hydrophobic association fracturing fluid thickener (HAT-1) was synthesised by using acrylamide (AM), acrylic acid (AA), 2-acrylamide-2-methylpropanesulphonic acid (AMPS) and N-dodecyl acrylamide (N-DAM) as raw materials. The factors that influenced synthetic process of HAT-1 were investigated and the optimum synthetic conditions were obtained as follows: reaction temperature -70 degrees C, polymerisation time -4 h, total monomer amount -25%, initiator amount -0.03% (compared to total monomer amount), pH value of the reaction system -8, monomer molar ratio of AM, AA, AMPS, N-DAM -80:15:4:1. Laboratory evaluation shows that HAT-1 fracturing fluid system has better performances on heat resistance, shear resistance, sand-carrying capability and gel-breaking property. Residue content of HAT-1 broken fluid is lower than regular fracturing fluid, could satisfy the fracturing operation requirement for the reservoirs below 90 degrees C.