Study on the influence of non-temperature factors on the migration path of organic carbon and evolution characteristics of pore permeability parameters of organic-rich shale under supercritical water in situ conversion

In this study, a non-isothermal heating reactor was used to simulate the hydrocarbon generation process of 1–4 cm sized medium-and low-maturity organic-rich shale under the action of supercritical water. The results show that the increase in pressure had a negative effect on the utilization of organic carbon in shale. As the pressure increased, the overall conversion efficiency of organic carbon decreased. Although higher pressure inhibited both oil and gas production, the inhibition of the gas production process was more significant. The effect of reaction time on oil and gas production differed in stages. Over a 4-h reaction period, the oil and gas production rates gradually increased with longer reaction times, with oil production showing a stronger promotion effect. Beyond 4 h, further extension of reaction time mainly promoted gas production. The increase in pressure and reaction time had opposite effects on the pore structure parameters of shale. Higher pressure led to a decrease in these parameters, while longer reaction times resulted in improved and expanded parameters.