Viscoelastic displacement mechanism of fluorescent polymer microspheres based on macroscopic and microscopic displacement experiments

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(4)

Published: April 1, 2025

Polymer microspheres represent a novel oil displacement agent that has demonstrated significant efficacy in oilfields. Recent research indicates the viscoelastic properties of polymer are crucial for displacement. To further elucidate mechanism, series fluorescent microspheres, P(AM-BM-AA-[Br−Flu]), with varying elasticity were synthesized via inverse suspension polymerization, incorporating monomers derived from fluorescein (Br−Flu). The micromorphology and systematically characterized using an infrared spectrometer, scanning electron microscope, inverted fluorescence laser particle size analyzer, rheometer. Through microscopic macroscopic experiments, along microsphere concentration tests, mechanism was investigated. results indicate P(AM-BM-AA-[Br−Flu]) exhibiting green successfully synthesized. By adjusting crosslinker concentration, different elasticities produced. During process, governs their migration mode within pore throats. Microspheres higher exhibit greater sweep efficiency. pushing carrying effect on residual droplets, positive pressure breakthrough resulting trapping, blind-end collectively enhance efficiency microspheres. From force analysis perspective, plays pivotal role improving both These findings provide experimental support understanding mechanisms developing new microsphere-based agents.

Language: Английский

Calcium Precipitates as Novel Agents for Controlling Steam Channeling in Steam Injection Processes for Heavy Oil Recovery

Processes, Journal Year: 2025, Volume and Issue: 13(5), P. 1319 - 1319

Published: April 25, 2025

Unconventional heavy oil reservoirs are particularly susceptible to steam breakthrough, which significantly reduces crude production. Profile control is a crucial strategy used for stabilizing production and minimizing costs in these reservoirs. Conventional plugging agent systems the thermal recovery of currently fail meet high-temperature, high-strength, deep profile requirements this process. Precipitation-type calcium salt blocking agents demonstrate long-term stability at 300 °C concentrations up 250,000 mg/L, making them highly effective channeling blockage during injection stages recovery. This study proposes two types precipitation-type agents: CaSO4 CaCO3 crystals. The precipitation behavior was investigated, their dynamic growth patterns were examined. sulfate exhibits slower crystal rate, allowing single-solution injection, while carbonate precipitates rapidly, requiring dual-solution injection. Both incorporate scale inhibitors delay crystals, aids control. Through microscopic visualization experiments, micro-blocking characteristics within pores compared, elucidating positions precipitated salts under porous conditions. Calcium crystals preferentially precipitate block larger pore channels, whereas more evenly distributed throughout reducing reservoir’s heterogeneity. final single-core displacement experiment demonstrated sealing properties systems. developed exhibit excellent performance.

Language: Английский