Preparation and rheological properties of acrylamide-based penta-polymer for ultra-high temperature fracturing fluid

Abstract

In this study, a penta-polymer PADAAN is prepared with acrylamide (AM) as the main chain material, acrylic acid (AA) as the carboxyl monomer, N-vinylpyrrolidone (NVP) as the temperature resistant monomer, N, N-dimethylacrylamide (DMAM) as the cross-linking monomer and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as the salt resistant monomer. Firstly, the best proportions of the monomers are determined, and then the rheological properties and microstructure of the polymer solution itself are studied. The 0.6 wt% PADAAN solution has a wide linear elastic region and it has good viscoelasticity and has good research value in its use as a fracturing fluid-based solution; The time required for restructuring the system structure is short and the spatial structure recovery ability is strong; The temperature resistance experiment of the fracturing fluid system (0.6 wt% PADAAN thickener base solution, 1 wt% cross-linking agent FAC-24,0.5 wt% pH regulator HAC20, 0.8 wt% FAT composited ratio deoxidizer, 0.2 wt% methanol)formulated by thickener found that the viscosity retention values of PADAAN are greater than 50mPa·s at 255 ℃, 265 ℃ and 275 ℃ respectively. In general, the new penta-polymer studied in this study can be used as a thickener for ultra-high temperature fracturing fluid with temperature resistance above 275 °C, which not only provides a reference for subsequent rheological studies of temperature-resistant polymers, but also has broad application potential in the field of hydraulic fracturing in oil and gas fields.