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Deep carbonate rocks are characterized by strong heterogeneity and fracture and cavity development, which have important influence on the storage and seepage capacity of reservoirs. To comprehensively characterize the developmental characteristics of the reservoir body in the intra–platform reservoir of the fourth member of the Dengying Formation in the Anyue gas field, this study employed a multiscale pore–throat structure characterization method that combines physical property analysis, core surface observation, cast thin section observation, a nuclear magnetic resonance (NMR) test, and CT scanning analysis. The results reveal that the primary storage spaces in the intra–platform reservoirs consist of inter–crystalline pores and small cavities (<2 mm), with thick throats and fractures serving as the primary flow channels. The rock density is lower in areas where solution fractures and cavities are developed, and the fractures and cavities are generally distributed in clusters. Notably, the intra–platform reservoir of the fourth member of the Dengying Formation is characterized by low asphaltene content. The presence of fractures in fracture–cavity type cores can reduce seepage resistance in the near–fracture area and enhance the drainage efficiency of small pores, as observed in the NMR test combined with centrifugation. In the centrifugal experiments, the increase in centrifugal force had the most significant impact on drainage efficiency, with the highest efficiency being 25.82% for cavity–type cores and the lowest being 6.39% for pore–type cores. Furthermore, by integrating the results of cast thin section and NMR test, the cavity–type reservoirs were further classified into two categories: dissolved cavity storage type and dissolved pore storage type. This study clarifies the storage and seepage characteristics of dissolved–pore storage reservoirs, which are challenging to develop but have high development potential. With reasonable surface operation measures, these reservoirs can provide important support for stable production in the middle and late stages of intra–platform reservoir development. [ABSTRACT FROM AUTHOR]

Controlling the extent of water invasion in the reservoir and mitigating its detrimental effects on gas well production and natural gas recovery have long been a challenging task in the efficient development of strongly heterogeneous edge water gas reservoirs. To elucidate the edge water invasion mechanism of strongly heterogeneous carbonate gas reservoirs, this study investigates the pore throat characteristics and fluid mobility from both qualitative and quantitative aspects, leveraging natural core observations, cast thin sections, scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) tests with centrifuge experiments. A core-scale edge water invasion simulation experiment was conducted under online NMR monitoring to examine the dynamic gas production characteristics of the three types of reservoirs during the water invasion process and to elucidate the formation mechanism and distribution pattern of water-sealed gas. Research findings indicate that carbonate reservoirs typically exhibit a diverse range of pore types, including various types of fractures and cavities. Fractures significantly enhance reservoir connectivity, thereby increasing fluid mobility, but also lead to strong non-uniform water invasion. In contrast, cavities substantially improve the storage capacity of the reservoir and can retard the advancement of the water invasion front, thereby alleviating the adverse effects of water invasion. The ultimate recovery rates of fracture-type, cavity-type, and fracture-cavity cores in the water invasion simulation experiment were 29.81%, 64.87%, and 53.03%, respectively. Premature water breakthroughs in the reservoir can result in a large number of gases in matrix pores and even cavities being sealed by formation water, rendering them unrecoverable, which seriously impacts the gas recovery rate of the reservoir. [ABSTRACT FROM AUTHOR]

The post-radiation effect of three kinds of disposable medical protective clothing made of polyethylene terephthalate/polyurethane (PET/PU), polypropylene/polyethylene (PP/PE), and polyethylene (PE) after radiation sterilization and the effects of radiation on the properties of protective clothing were investigated. The changes in surface morphology, hydrophilicity, mechanical properties, and free radicals of medical protective clothing materials after radiation sterilization were systematically studied using scanning electron microscopy (SEM) and electron spin resonance (ESR) spectroscopy, and by examining the surface contact angle and tensile properties at break. The results showed that the surface morphology of protective clothing made of PET/PU, PP/PE, and PE undergoes no obvious change after γ-ray irradiation. However, the hydrophobicity of the surfaces—whose contact angles were reduced by 2.8%, 7.9%, and 17.8%, respectively—decreased. γ-ray irradiation has little effect on the tensile properties of PET/PU at the sterilizing dose (≤ 50 kGy). On the other hand, the tensile breaking strength and elongation at break of PP/PE and PE protective clothing decreased with the increasing absorbed doses. The signal intensity of free radicals produced by PP/PE and PE protective clothing increased with the absorbed dose and the concentration of free radicals decreased rapidly with the storage time and tended to stabilize after one month.

It is challenging to endow poly(methyl methacrylate) (PMMA) with good dielectric properties and UV absorption capacity while simultaneously overcoming its poor heat resistance. Herein, we report for the first time a novel organic–inorganic hybrid (PMMA‐HBPSi) derived from methyl methacrylate (MMA) and hyperbranched polysiloxane (HBPSi) fabricated via γ‐radiation curing. The typical properties (thermal stability, optical characteristics, and dielectric properties) of the hybrids were systematically investigated and discussed. The results demonstrated that the incorporation of HBPSi into the PMMA resin not only increased the thermal resistance, dimensional stability, and dielectric properties but also remarkably reduced the UV transmittance. Specifically, in comparison with pure PMMA, the initial degradation temperature (Tdi) of PMMA‐HBPSi increased by 31°C, with no phase transition occurred in a temperature range of 60–230°C, thus illustrating a significant improvement in the glass‐transition temperature. Moreover, the thermal expansion coefficient decreased by 86.9% at temperatures exceeding 118°C. The UV transmittance of PMMA was also found to decrease by 80% at 295 nm after the introduction of HBPSi. These attractive features of PMMA‐HBPSi demonstrate that the new approach proposed here is suitable for developing high‐performance organic glasses for optical, aviation, and electronic applications. [ABSTRACT FROM AUTHOR]

Heat‐resistant, highly surface‐hardened, and transparent composites of poly(methylmethacrylate) (PMMA) play a significant role in modern devices. However, conventional PMMA‐based composites with high nanoparticle loadings often compromise transparency for high surface hardness and heat resistance due to nanoparticle aggregation and poor interfacial compatibility. In this work, we successfully fabricated an exceptional composite (MSiO2/PMMA composites) with high transparency, superior heat resistance, and high surface hardness using γ‐ray irradiation‐induced polymerization of methyl methacrylate (MMA) containing uniformly dispersed SiO2 that was modified by 3‐methacryloxypropyl trimethoxysilane and trimethylchlorosilane. Specific silanes were utilized for polarity regulation to reduce the agglomeration of SiO2 nanoparticles and improve compatibility with MMA. Compared to pure PMMA, the 40‐MSiO2/PMMA composite sample exhibited significantly improved thermal stability in terms of the temperature at 10% weight loss (T10%), glass transition temperature (Tg), and decreased coefficient of thermal expansion (CTE). Furthermore, this composite achieves a very high surface hardness (pencil hardness of 6H versus H for pure PMMA) while maintaining transparency similar to PMMA. These MSiO2/PMMA composites open up new avenues to enhance the performance and durability of materials used in various industries such as electronics, optics, automotive, and aerospace. [ABSTRACT FROM AUTHOR]