RESUMEN
Nano-Pour point depressants have great potential to improve the low-temperature fluidity of waxy crude oil. This Review reviews the recent research progress of nano-pour point depressants in the field of crude oil pour point reduction. The effect and mechanism of nanocomposite pour point depressants are analyzed; the preparation, modification, and microstructure characterization of nanocomposite pour point depressants are introduced; the three main types of nano-pour point depressants, namely, silicon-based, carbon-based, and magnetic metal-based, are introduced; the results of the current research are outlined; and the challenges of the current research and possible directions of future research are also pointed out. The in-depth analysis of nano-pour point depressants and their potential to improve the low-temperature fluidity of waxy crude oil are reviewed in order to thoroughly analyze the mechanism of nano-pour point depressants and to prepare nano-pour point depressants that are more suitable for reducing crude oil coagulation.
RESUMEN
Matrix-related pores play a significant role in controlling hydrocarbon production in organic-rich shales. Multiple matrix-related pore types of typical marine shales in the Sichuan Basin have been visually investigated and identified by transmission electron microscopy (TEM) on ultra-thin sections and by focused ion beam-scanning electron microscopy (FIBSEM) on polished sections. OM-hosted pores seem universal and range in sizes from below 1 nm to hundreds of nanometers and they are not homogeneously developed and distributed, which is mainly determined by thermal maturity and OM composition. Mineral-hosted pores are defined by mineral frameworks and occur in open spaces related to ductile or rigid grain fabric. The four porous mineral types that occur are clay intrapores, carbonate solvopores, pyrite interpores, and quartz interpores, and they range in size from less than 1 nm to more than several microns. Aggregate-hosted pores are predominantly associated with clay-organic aggregates, pyrite-organic aggregates, clay-pyrite aggregates, and clay-organic-pyrite aggregates. The most common aggregate-hosted pore networks are defined by clay-organic aggregates, and the pores are largely developed between the clay and organic layers and may be the important adsorption spaces for methane. Fracture-related pores include microchannels and microfractures of various sizes and shapes and they could play a key role in providing hydrocarbon migration pathways. FIBSEM and TEM show direct evidence that OM-hosted pores and fracture-related pores contribute more to the effective pore network and the excellent reservoir quality, whereas poor reservoir quality may come from aggregate-hosted pores.
