Self-assembly networks of wormlike micelles and hydrophobically modified polyacrylamide with high performance in fracturing fluid application

Abstract

Dynamic rheology and steady shear viscosity of an aqueous salt solution of 2 wt% viscoelastic gemini surfactant 1,2-N,N′-bis (dimethyloctadecyl) ethene ammonium bromide and its mixture with low molecular weight hydrophobically modified polyacrylamide (HMPAM) were investigated. The solution of surfactant in the presence of potassium chloride exhibited typical Maxwellian fluid behavior with a single stress relaxation time, indicating the formation of transient networks of entangled wormlike micelles (WLMs). Polymer profoundly affected the rheological properties of WLMs.The WLMs/HMPAM system demonstrated higher plateau modulus and zero-shear viscosity than the single WLMs system by self-assembling into common networks which was identified by scanning electron microscopy morphology. In contrast to the WLMs system, the WLMs/ HMPAM system exhibited better temperature and shear resistance while retaining complete responsiveness to hydrocarbons. Based on the fracturing fluid application evaluation, the WLMs/HMPAM system had an applicable temperature, which was 30°C higher than the WLMs system, and the core damage rate showed that the WLMs/HMPAM system was very promising in clean fracturing fluid application.

Self‐assembly properties of ultra‐long‐chain gemini surfactant with high performance in a fracturing fluid application

“…As discussed previously, the C25‐6‐C25 system with KCl can self‐assemble in intensive networks compared with the pure C25‐6‐C25 solution. SEM morphologies demonstrate that the addition of KCl profoundly promotes the formation of a three‐dimensional network structure, which could explain why the C25‐6‐C25/KCl system is more resistant to shear and can maintain a high level of viscosity at 100 and 110 °C . Meanwhile, the viscosity of pure C25‐6‐C25 solution is similar to that of water at 100 and 110 °C.…”

“…SEM morphologies demonstrate that the addition of KCl profoundly promotes the formation of a threedimensional network structure, which could explain why the C25-6-C25/KCl system is more resistant to shear and can maintain a high level of viscosity at 100 and 110 8C. 15 Meanwhile, the viscosity of pure C25-6-C25 solution is similar to that of water at 100 and 110 8C. The structure in Figure 8(b) and the motion of C25-6-C25 could explain this phenomenon.…”

“…11 To our best knowledge, the VES system's viscoelastic resistance to high temperature and high shearing is due to forming transient networks by self-assembly and entanglement processes of the surfactants. 15,16 Gemini surfactants usually self-aggregate at lower concentrations and display superior surface-active behaviors and rheological properties compared with their corresponding monomeric surfactants. 17,18 For this reason, we designed a gemini surfactant that displayed improved viscoelasticity and degradation ability and could be obtained from a low-cost feedstock.…”

CO2‐switchable polymeric vesicle‐network structure transition induced by a hairpin‐line molecular configuration conversion

“…The polymeric vesicles exhibited some advantages over other conventional artificial vesicles, such as better durability, wider designability, and without using of organic solvents . The remarkable rheological property change of water triggered by the wormlike micelles have found significant application in the enhanced oil recovery and the fracturing operation of oil fields …”

“…11,12 The remarkable rheological property change of water triggered by the wormlike micelles have found significant application in the enhanced oil recovery and the fracturing operation of oil fields. 13,14 Stimuli-responsive assemblies are attracting more and more attention because they can undergo reversible changes (such as phase inversion, shape variation, and systemic assembly and disassembly) in response to the external stimuli such as pH value, temperature, light, reducing or oxidizing agents, and even voltage. [15][16][17][18][19] In comparison with these external stimuli, CO 2 is a new attractive trigger for stimuli-responsive materials due to its availability, cost-efficiency and benign nature.…”