Log Evaluation Method for Adsorbed Gas Amount in Deep Shale Based on Modified BET Multilayer Adsorption Model
Gas content is a key index of shale reservoir evaluation. The gas content is influenced by the coupling of temperature and pressure. Especially under high formation pressure, it's difficult to accurately predict the adsorbed gas amount of shale reservoirs. Regarding the methane adsorption characteristics in deep shale gas reservoirs under high-temperature and high-pressure condition, a modified BET multi-layer adsorption model is derived. A set of log evaluation methods for adsorbed gas amount of deep shale reservoirs has been established. By applying this method to evaluate the gas content of deep shale reservoirs in southern Sichuan basin, the results show that the adsorbed gas amount calculated by modified BET multi-layer adsorption model is more in line with the actual geological conditions. Combined with the free gas volume corresponding the depth, the total gas content of shale is calculated by this method, and the result is accurate and consistent with that obtained by on-site pressure maintaining coring. The evaluation method of adsorbed gas amount based on the modified BET multi-layer adsorption model has good adaptability in deep shale gas blocks in southern Sichuan basin, and provides strong technical support for geological dessert evaluation and resource potential analysis of deep shale.
Sichuan basinadsorbed gas amountisothermal adsorption experiment,BET adsorptiongas content
万方数据
维普
