Synthesis of a water‐soluble chain transfer agent and its application in gel dispersions

Abstract

Pre‐crosslinked gel particles, colloidal dispersion gels, and polymer microspheres are often used as profile‐controlling and flooding agents to displace residual crude oil from formations. The preparation process of these profile‐controlling and flooding agents is complicated. In order to simplify the preparation steps, a water‐soluble chain transfer (RAFT) agent, S,S′‐bis(2‐propionic acid) trithiocarbonate (PATTC), was synthesized, and then, hydrogel dispersions were prepared by one‐pot RAFT polymerization. The structure of PATTC was confirmed by infrared spectroscopy and nuclear magnetic resonance. The effects of reaction conditions on the viscosity and viscosity‐average molecular weight of hydrogel dispersions were explored, the rheology, viscoelasticity, particle size, temperature responsiveness, and salinity responsiveness of hydrogel dispersions were measured, and the seepage properties of hydrogel dispersions in porous medium were analyzed. The results show that at higher shear rates, the polyacrylamide gel dispersions exhibited Newtonian fluid characteristics. Viscoelasticity tests further confirmed that the polyacrylamide gel dispersions were successfully synthesized. The particle size of the hydrogel dispersions is 1–75 μm, its viscosity is less affected by temperature and salinity, and its residual resistance coefficient is higher than that of the polyacrylamide solution under similar apparent viscosity.

An Overview of Polymeric Hydrogel Applications for Sustainable Agriculture

“…Several approaches are used in this polymerization process, including bulk, solution, suspension, and emulsion polymerization [46]. Additionally, there are non-conventional techniques for radical polymerization, like reversible additionfragmentation chain transfer polymerization (RAFT) [54] and atom transfer radical polymerization (ATRP) [55].…”

Effect of Chemical Composition of Metal–Organic Crosslinker on the Properties of Fracturing Fluid in High-Temperature Reservoir

“…Although B crosslinkers have the ability to crosslink effectively with guar and their fracturing fluid possesses good shear resistance, they have limited high-temperature resistance, and their coordination bond with guar gum will break at 140 °C [ 19 , 20 ]. In comparison, Zr crosslinkers are a good choice for high-temperature conditions; however, the disadvantage of fracturing fluids formed with commercial zirconium crosslinkers is poor shear resistance [ 21 , 22 , 23 ]. Therefore, it is necessary to use matched components to control the release rate of metal ions from the crosslinkers, thereby delaying the crosslinking of the polymer and crosslinker until the fracturing fluid passes through the high-shear environment [ 24 , 25 ].…”

Fundamental Studies on Fluids-Independent Regenerative Nanocomposite Hydrogels for Fracture Treatments of Conformance Control

“…Polymeric hydrogels such as in situ gels and granular hydrogels have been used for the treatment of fractures and fissures since the fluid loss and productivity reduction posed technical challenges during enhanced oil recovery and drilling operations. − For instance, the reservoir fluids potentially threaten the safety of personnel and equipment in drilling operations. , However, pilot tests of in situ gels to treat large-size fractures in the past two decades demonstrated their limitations of intrinsic mechanical weakness due to low concentrations of polymer precursors . High viscosity and uncontrolled gelation of the current in situ gels led to injectivity difficulty and low plugging efficiency .…”