In recent years, polymers used as thickeners in fracturing fluids tend to pursue a higher molecular weight for better thickening performance. However, these polymers experience mechanical degradation under high shear conditions. To improve the adaptability of polymer fracturing fluids to mechanical shear, a novel hydrophobically associating polymer (HALMP) was developed by enhancing the hydrophobic association action (to improve viscosity and elasticity) while decreasing the molecular weight (to avoid shear degradation and ensure solubility) and characterized by 1H NMR and infrared tests. The calculated molecular weight of HALMP from intrinsic viscosity is 150 × 104 g/mol, and it was concluded that there is strong hydrophobic association in polymer solution from the microscopic structure and macroscopic properties by pyrene fluorescence probe technique, viscoelasticity, and thixotropy tests. Meanwhile, the critical association concentration and the aggregation pattern of polymer molecules in solution were investigated. The shear recovery tests and scanning electron microscopy revealed that the polymer solution contains a dynamic physical crosslinking network that can be “healed” by the intermolecular hydrophobic association action after being sheared. The results also show that HALMP exhibits excellent thickening performance even at a high shear rate. These findings not only demonstrate the feasibility of polymer fracturing fluids with strong association and low molecular weight but also offer alternative methods to prepare high-functional polymers.
This study proposes a kill two birds with one stone strategy to improve the health and safety of pork with high internal phase Pickering emulsions (HIPPEs). HIPPEs improved the pseudoplasticity and viscosity (from 619.3 to 1712 Pa·s at 0.1 s −1 ) of the pork, favoring smooth extrusion and adhesion of the ink. Shear recovery of pork gel increased from 39.20 % to 77.78 % by addition of HIPPEs. HIPPEs enhanced the pork gel viscoelastic properties (K 4 = 341.29, K 5 = 453.11) and yield stress (268.55 Pa). HIPPEs-adjusted pork gel (HPG) has favorable 3D printing, pork aroma, safe swallowing (level 5 food), and high digestibility (80.40 %), demonstrating its potential as a dysphagia diet. HPG reduced the cooking loss of pork (from 30.8 % to 1.9 %), which is suitable for dysphagic patients with reduced salivation. HIPPEs adjusts the properties of pork gel by filling and winding gel networks. These results provide new ideas for the development of special formula foods.
In order to broaden the application of clean fracturing fluid in ultra-high temperature reservoirs, a surfactant gel for high-temperature-resistant clean fracturing fluid was developed with a gemini cationic surfactant as the main agent in this work. As the fracturing fluid, the rheological property, temperature resistance, gel-breaking property, filtration property, shear recovery performance and core damage property of surfactant gel were systematically studied and evaluated. Results showed the viscosity of the system remained at 25.2 mPa·s for 60 min under a shear rate of 170 s−1at 200 °C. The observed core permeability damage rate was only 6.23%, indicating low formation damage after fracturing. Due to micelle self-assembly properties in surfactant gel, the fluid has remarkable shear self-repairability. The filtration and core damage experimental results meet the national industry standard for fracturing fluids. The gel system had simple formulation and excellent properties, which was expected to enrich the application of clean fracturing fluid in ultra-high temperature reservoirs.Keywords:clean fracturing fluid;VES;surfactant gel;rheology behavior;thermal stability
危险品化学品经营许可证（带存储）