2.0 nm to the competitive adsorption of CH and CO in terms of the CH recovery and residual CH and CO 4 2 4 4 2 adsorption after the displacement. The results showed that the micropores have different contributions to the CH recovery depending on the pore size, CO ratio, temperature, and pressure. The pores below 0.61 nm make 4 2 no contribution to CH recovery, but the 0.55 - 0.60 nm pores are beneficial for CO storage. The 0.65 - 0.70 nm 4 2 pores show the highest CH storage capacity and a high selectivity for CO . As a result, the CH recovery 4 2 4 reaches the maximum and is not affected by CO ratio. Besides, the pores above 1.3 nm provide little to the CH 2 4 recovery at lower pressures, and the injected CO ratio changes the optimum pore size in terms of the maximum 2 CH recovery. The pore size for the maximum CH recovery decreases slightly with the increase of pressure. In 4 4 addition, the CH recovery density is higher at lower temperatures due to higher preadsorption of CH and 4 4 lower residual CH capacity. Furthermore, the distribution of the adsorbed CH and CO after the displacement 4 4 2 showed that the residual CH distribution is not affected by the injected CO and is randomly located among the 4 2 adsorbed CO molecules. 2

Zhang, H., Huang, H., Li, Z., Liu, M., 2020. Comparative study between sequential solvent-extraction and multiple isothermal stages pyrolysis: A case study on Eocene Shahejie Formation shales, Dongying Depression, East China. Fuel 263, 116591.

http://www.sciencedirect.com/science/article/pii/S0016236119319453 Chemical and thermal extractions were performed on a suite of 23 shale core samples, from the Eocene Shahejie Formation of the Dongying Depression, East China, to investigate the Oil-In-Place of shales and the difference among various assessment approaches. The novel multiple isothermal stages (MIS) pyrolysis AAPG European Regional Conference &Exhibition. [Romero-Sarmiento et al., Lisbon; 2015] derives four peaks characterizing the light, light to medium, heavier- and non- hydrocarbons, and the pyrolyzed hydrocarbon (i.e., hydrocarbons derived from thermal decomposition of kerogen), respectively. Compared with standard Rock-Eval pyrolysis on OIP estimation, the MIS pyrolysis provides more specific information concerning gross compositions and physical status of oils, which reduces the impact of the frequently-occurred carryover effect to n a certain extent. Systematic variations of molecular compositions especially the light vs. heavy -alkanes have been elucidated. The mobile oil estimated from MIS pyrolysates is very close to solvent extractable oils (i.e., bitumen). Abnormal increase of pyrolysis hydrocarbons after initial extraction is attributed to the mineral matrix effect. This study demonstrated discrepancies between various approaches in assessment of thermo-vaporizable and pyrolysis hydrocarbons within shale reservoirs and triggered a re-understanding on the application of pyrolysis parameters in shale oil systems.

Zhang, H., Jiang, Y., Zhou, K., Fu, Y., Zhong, Z., Zhang, X., Qi, L., Wang, Z., Jiang, Z., 2019. Connectivity of pores in shale reservoirs and its implications for the development of shale gas: A case study of the Lower Silurian Longmaxi Formation in the southern Sichuan Basin. Natural Gas Industry 39, 22-31.

http://oversea.cnki.net/kcms/detail/detail.aspx?dbCode=cjfd&QueryID=20&CurRec=5&filename=TRQG20191 2005&dbname=CJFDAUTO In Chinese. The unconnected gas-bearing pores in shale gas reservoirs may be transformed into "potential recoverable pores" after largescale hydraulic fracturing. However, the mainstream pore classification methods of shale gas reservoirs, do not take the unconnected pores into account, which impacts the evaluation accuracy of reservoir pore effectiveness. To solve this problem, this paper took the shale of Lower Silurian Longmaxi Formation in the southern Sichuan Basin as the research object to carry out experiments on core porosity, centrifugal + gradual drying NMR after saturated with brine and NMR freeze-thaw using plunger samples and fragmented samples to analyze the volume, main development location and main pore size distribution range of unconnected pores. Then, the pore systems were classified, and the lower limit of effective pore size of connected gas-bearing pores was determined. Finally, the total pore effectiveness of shale gas reservoirs was evaluated, and the influence of unconnected pores on the development of shale gas was discussed. And the following research results were obtained. First, there are a large number of unconnected pores in the shale gas reservoirs of the study area, accounting for 30.23%. Most of them are mainly developed in organic matters and a few are developed in clay minerals. The distribution of pore size ranges from 5 nm to 30 nm. Second, T cut- 2 off value of clay bound water in the shale gas reservoirs of the study area is 0.26 ms, whose corresponding pore