Study on preparation and properties of polyurethane modified epoxy resin lotion cementing slurry

Abstract

To solve the problems of poor cementing quality and weak consolidation performance of deep-water shallow cementing cement, a low-temperature curable polyurethane-modified epoxy resin lotion (WER) was prepared with epoxy resin and polyurethane as raw materials, and its hydrophilic groups (carboxyl and ether bonds) were self-emulsified. The results show that the viscosity of WER lotion is maintained between 100-200mPa · s at 25 ℃ -60 ℃, and it has a high slurry stability and an apparent viscosity lower than 300mPa · s when used as a flexible admixture of cement slurry. When 15% WER lotion is added, the filtrate loss of cement slurry is less than 40mL, and the thickening transition time is less than 16min, which can effectively prevent gas channeling. In addition, the low-temperature mechanical properties of WER lotion cement paste have been significantly improved. Its compressive strength has increased by 42.4% and 44.5% in 3d and 7d compared with neat cement paste, while its elastic modulus has decreased by 34.1% and 42.4%, respectively, showing excellent toughening effect, which will be conducive to improving the consolidation effect on shallow weak formations and enhancing the cementing performance between casings and formations.