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Despite the abundance of shale-oil and tight-oil reserves in the Fengcheng Formation within the Mahu Sag, exploration and development efforts for both types of reservoir are still in their early stages. A comprehensive examination and comparison of the pore structures of these reservoirs can establish rational classification and evaluation criteria. However, there is a dearth of comparative analyses focusing on the pore structures of shale-oil and tight-oil reservoirs within the Fengcheng Formation. This study addresses this gap by systematically analyzing and comparing the pore structures of these reservoirs using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), low-temperature nitrogen adsorption, and mercury intrusion capillary pressure experiments (MICP). The results show that the shale oil within the Fengcheng Formation exhibits a higher content of carbonic acid compared to the tight-oil samples. Furthermore, it demonstrates smaller displacement pressure and median pressure, a larger sorting coefficient, and superior permeability in contrast to tight oil. Notably, the shale oil within the Fengcheng Formation is characterized by abundant striated layer structures and micro-fractures, which significantly contribute to the microstructural disparities between shale-oil and tight-oil reservoirs. These differences in microstructures between shale oil and tight oil within the Fengcheng Formation in the Mahu Sag region delineate distinct criteria for evaluating sweet spots in shale-oil and tight-oil reservoirs. [ABSTRACT FROM AUTHOR]

Microstructure characteristics of OGFC (open graded friction course) asphalt mixture are closely related to the mechanical behavior. To study the microstructure influence mechanism to mechanical behavior of OGFC asphalt mixture, the digital image processing technology is used to process the specimen's fault images and obtain the microstructure parameters of the OGFC asphalt mixture with different gradation. At the same time, the microstructure influence on mechanical behavior of OGFC asphalt mixture is explored by using the Grey correlation theory based on the experimental results of mechanical performance and the microstructure parameters. The influence of four key sieve passing percentage (1.18, 2.36, 4.75, and 9.5 mm) on the microstructure was discussed by using the Grey correlation theory, and the influence mechanism to mechanical behavior of OGFC asphalt mixture was further revealed. The results show that with the increase of air void content, the total void area, the equivalent pore diameter, and the number of big voids (here, 'big' means voids with an area greater than 10 [mm.sup.2]) increase, the length of void and corresponding void area increase synchronously, the drainage performance is enhanced, and the mechanical performance is decreased. With the increase of nominal maximum particle size, the average area of single void, the percentage of number of big voids, and the equivalent diameter increase, and the drainage performance, anti-skidding performance, and mechanical performance of pavement are enhanced. It is considered that the key sieve passing percentage affects the mechanical behavior by influencing the microstructure of asphalt mixtures. The influence degree of microstructure parameters on mechanical behavior and the influence degree of the key sieve passing percentage on microstructure parameters were obtained. The research results have a certain reference value for the optimization of mechanical behavior of OGFC asphalt mixture. Key words: open graded friction course (OGFC) asphalt mixture, mechanical behavior, microstructure, influence mechanism, Grey correlation analysis. Les caracteristiques de microstructure du melange d'asphalte a couche de frottement a texture ouverte (CFTO) sont etroitement liees au comportement mecanique. Afin d'etudier le mecanisme de l'incidence de la microstructure sur le comportement mecanique du melange d'asphalte a CFTO, la technologie numerique de traitement d'images est utilisee pour traiter les images de defauts de l'echantillon et obtenir les parametres de microstructure du melange d'asphalte a CFTO avec differente granularite. En meme temps, l'incidence de la microstructure sur le comportement mecanique du melange d'asphalte a CFTO est exploree en utilisant la theorie de correlation grise reposant sur les resultats experimentaux de la performance mecanique et les parametres de microstructure. L'incidence de quatre taux cles de passage au tamis (1,18, 2,36, 4,75 et 9,5 mm) sur la microstructure a ete examinee en utilisant la theorie de correlation grise, et le mecanisme de l'incidence sur le comportement mecanique du melange d'asphalte a CFTO a ete davantage revele. Les resultats montrent qu'avec l'augmentation de la proportion des vides interstitiels, la superficie totale des vides, le diametre de pores equivalent et l'augmentation du nombre de grands vides (defini que 'grand 'signifie la superficie des vides plus grands que 10 [m.sup.2]), la longueur des vides et la surface correspondante des vides augmentent de fa^on synchrone, la capacite de drainage est amelioree mais le rendement mecanique est amoindri. Avec l'augmentation de la taille maximale nominale des particules, la surface moyenne des vides uniques, l'augmentation du pourcentage du nombre de grands vides et du diametre equivalent, la capacite de drainage, les performances d'enduit antiderapant et les performances mecaniques de la chaussee sont ameliorees. On considere que le pourcentage cle de passage au tamis influe sur le comportement mecanique par son incidence sur la microstructure des melanges d'asphalte. Le degre de l'incidence des parametres de microstructure sur le comportement mecanique et le degre d'incidence du pourcentage cle de passage au tamis sur les parametres de microstructure ont ete obtenus. Les resultats de la recherche ont une certaine valeur de reference pour l'optimisation du comportement mecanique du melange d'asphalte a CFTO. [Traduit par la Redaction] Mots-cles : melange d'asphalte a couche de frottement a texture ouverte (CFTO), comportement mecanique, microstructure, mecanisme d'incidence, analyse de correlation grise., 1. Introduction The microstructure of open graded friction course (OGFC) has important influence on its macroscopic mechanical behavior (Wu et al. 2010; Xiao et al. 2010). The microstructure of asphalt [...]

This study investigates the drainage characteristics of different asphalt mixtures in different directions using a new selfmade water seepage test device. Among them, the pavement drainage characteristics of five aggregate gradations were analyzed, which include asphalt concrete (AC-20), stone matrix asphalt (SMA-20), SUPAVE (SUP-20), and open-graded frictional course (OGFC-13 and OGFC-16). In addition, the effect of the void ratio on the drainage characteristics of different asphalt mixtures was analyzed based on the results of the permeability test. Finally, the gray correlation theory was applied to rate the relationship between different sieve passage rates and drainage properties of asphalt mixtures. The results of the study show that the transverse flow is larger than the longitudinal flow and plays a major role in the drainage process. The water volume is negatively correlated with the permeability coefficient of variation (CV). In addition, the permeability CV in all directions shows a gradual decrease with the increase of the permeability coefficient. [ABSTRACT FROM AUTHOR]

The meso-structure of open-graded frictional course (OGFC) can significantly affect the heat transfer characteristics of the asphalt pavement. In this study, a laboratory simulation test device was developed to investigate the effect of aggregate gradations and void ratios on OGFC asphalt pavement heat transfer characteristics. Three aggregate gradations including asphalt concrete, stone mastic asphalt and OGFC were selected for pavement thermal resistance efficiency analysis. In addition, grey correlation theory was used to rate the relationship between different gradation ranges and thermal resistance efficiency. The test results show that this laboratory measurement device provides an effective method for estimating the thermal resistance of asphalt pavements. The OGFC asphalt mixture has the best thermal resistance performance compared to other grades. The air porosity and density have good linear relationship with the average temperature difference increment, and decreasing the density of the asphalt mixture or increasing the air voids content both increase the thermal resistance effect of the pavement. [ABSTRACT FROM AUTHOR]

Reasonable establishment of maintenance prediction mechanism plays an important role in service performance and long-term performance of asphalt pavement. The presented study proposed a comprehensive maintenance evaluation system framework of asphalt pavement based on the full-cycle. Firstly, Pavement maintenance cycle was divided into five stages and three important maintenance opportunities. Secondly, according to the theoretical formula method, the single index of pavement maintenance was studied, and the relationship between single index and service life was established. Combined with the empirical formula method and the measured data method, the evaluation standard of the full-cycle asphalt pavement comprehensive maintenance system was determined. Finally, based on the background of Har-tong expressway, the evaluation standard of comprehensive maintenance system in Heilongjiang Province of China under different maintenance periods was established. The results showed that the full-cycle comprehensive maintenance evaluation system can effectively predict the key nodes of asphalt pavement maintenance. In addition, the relevant maintenance standards can be formulated according to the driving data of different regions, which is helpful to establish an accurate maintenance evaluation system. This is conducive to saving maintenance resources, improving maintenance efficiency, and providing reference for future pavement maintenance construction. [ABSTRACT FROM AUTHOR]