Application of Solvent-Assisted Dual-Network Hydrogel in Water-Based Drilling Fluid for Lost Circulation Treatment in Fractured Formation.

During oil and gas well construction, lost circulation caused substantial nonoperation time and extra costs, and hydrogel, resilient and environmentally friendly, was one of the major types of material for lost circulation treatment. To migrate the weak bonding and hydrothermal degradation of conventional single network hydrogels, dual network (DN) hydrogel was prepared and immersed in solvents of polyethylene glycol (PEG), ethylene glycol, and glycerol. The swelling of DN gels at different temperatures was studied with water content and swelling rate tests, and the gel structural and morphology was characterized with attenuated total reflectance infrared spectroscopy (ATR-IR) and scanning electron microscopy test.

Multiple Hydrogen Bonding-Assisted High-Strength Hydrogel of Silica/Polyacrylamide Nanocomposite Cross-Linked with Polyethylenimine.

The nanocomposite gel system has been successfully applied as a water shutoff agent to enhance oil recovery (EOR) or for plugging to control lost circulation events. In this study, the silica/polyacrylamide nanocomposite was synthesized via in situ free radical polymerization of acrylamide (AM) monomers in the presence of silica nanoparticles. The composite was cross-linked with polyethylenimine to prepare a high-strength hydrogel.

Identifying interactions of linked irrigated lake-groundwater system by combining hydrodynamic and hydrochemical method.

During the irrigation period, the interactions between the linked lake-groundwater systems are complicated and change. This is because natural and human activities are happening at the same time, which makes it harder to identify the interactions. This study uses data on water level, hydrochemistry, and hydrogen-oxygen stable isotopes to analyze the hydrodynamics, electrical conductivity (EC), isotopic characteristics, and spatial distribution of lake water and groundwater to reveal lake-groundwater interactions.