A heterostructured PAN–PPy/ZnO nanofibrous membrane with superhydrophilicity/underwater superoleophobicity and regeneration capacity to efficiently and quickly remediate the complex oily sewage system.

Owing to the harsh downhole environments, poor dispersion of silica at high salinity and high temperature can severely restrict its application as the nano-plugging agent in shale gas exploitation. The objective of this study is to improve salt tolerance and thermal stability of silica. Herein, silica was successfully functionalized with an anionic polymer (p SPMA) by SI-ATRP (surface-initiated atom transfer radical polymerization), named SiO₂-g-SPMA. The grafted pSPMA brushes on silica provided sufficient electrostatic repulsion and steric repulsion for stabilizing silica in a harsh environment. The modified silica (SiO₂-g-SPMA) had excellent colloidal stability at salinities up to 5.43 M NaCl (saturated brine) and standard API brine (8 wt% NaCl + 2 wt% CaCl₂) for 30 days at room temperature. Simultaneously, the SiO₂-g-SPMA was stable at 170 °C for 24 h as well as stable in weakly alkali environment. Furthermore, the plugging performance of SiO₂-g-SPMA in water-based drilling fluids for low permeate reservoir reached to 78.25% when adding a small amount of 0.5 wt% SiO₂-g-SPMA, which effectively hindered the water invasion into formation and protected the reservoir.

A hyperbranched polyamine was synthesized by self‐condensing vinyl polymerization with divinyl sulfone, N‐phenyl‐p‐phenylenediamine, by A₂+ approach. The hyperbranched polyamine was characterized by FT‐IR, TGA, and phase analysis light scanning. Average grain diameter of hyperbranched polyamine was 36.7 nm. Hyperbranched polyamine has good thermal stability. Hyperbranched polyamine (HBPA) was employed successfully as nanoplugging agent in oil‐based drilling fluid system, which could plug nanopore formation in shale formation. HBPA has a little effect on rheological properties of oil‐based drilling fluid and the FL_APIand FL_HTHPdecreased dramatically with an increase of hyperbranched polyamine. Emulsion‐breaking voltage has a slight increase, which is beneficial to maintain stability of oil‐based drilling fluid. When the HBPA concentration is greater than 1 wt%, plugging rate of oil‐based drilling fluid for artificial core is close to 100% and the permeability recovery value can reach 99.7% after adding 1 wt% HBPA, which prove that HBPA has an excellent plugging performance.

Shale gas as green and clean energy is attracting more interest. However, shale hydration and swelling have become the major challenges using water‐based drilling fluids, replacing oil‐based drilling fluids, for developing shale gas. In this work, a low molecular weight branched polyamine (NETS) as clay swelling inhibitor was synthesized. The NETS performed excellent inhibition property by linear expansion experiments and cuttings hot‐rolling recovery. The inhibition mechanism of NETS was investigated using X‐ray diffraction, fourier transform infrared spectroscopy, cation exchange capacity, X‐ray photoelectron spectroscopy, scanning electron microscopy, and zeta potential. The results show that the NETS can adsorb on Na‐Mt, decrease the basal spacing of wet Na‐Mt from 1.91 to 1.43 nm, and replace majority sodium ions from interlayer of Na‐Mt. However, replaceability of sodium ions and inhibition of water molecules of ethylenediamine are worse than NETS. These indicate that the primary amines of NETS had strong interaction with Na‐Mt, tensed clay layers and decrease the basal spacing. The combination of long hydrophobic chain and primary amines makes NETS to adsorb on surface of Na‐Mt, intercalate into interlayer of Na‐Mt with tilted monolayer arrangement, and replace sodium ions. The more the number of primary amine groups, the better the inhibition performance. Therefore, NETS has a great potential to be an outstanding shale inhibitor of water‐based drilling fluids in the future.

Metal–organic frameworks (MOFs) for persulfate-based Fenton-like processes have attracted tremendous attention nowadays. However, the low utilization of active sites and poor stability of MOFs still impede their practical application. In this work, we demonstrate a unique photo Fenton-like catalyst with confined ultrasmall MOF nanoparticles anchored on a 3D-graphene network, which is fabricated through a simple confined thermal pulverization method. The ultrasmall Co–Fe MOF nanoparticles with confined structure endowed this catalyst with highly exposed active sites as well as excellent stability. It can maintain high degradation efficiency via visible light-assisted peroxymonosulfate (PMS) activation in a broad pH range from 1–13. Electron spin resonance (ESR) technology reveals that both radical and nonradical processes are involved in this process, and the broad pH adaptability of this system is due to the stable generation of ˙OH, SO₄˙⁻, ˙O₂ ⁻, and ¹O₂ under these pH conditions. This study provides new perspectives for the development of highly efficient and harsh environment-adaptive MOF-based Fenton-like catalysts.