GUO Xinyang (1983-), male, Ph.D., Senior Experimentalist. E-mail: gdayang@163.com
For the degradation of oil well set-cement under CO2 sequestration condition, the thermodynamic conditions of pure minerals related to hydration products degradation were determined based on the equilibrium constant theory, and the resistance difference was investigated. The mass change of hydration products was simulated based on the Gibbs free energy minimization principle. The results show that the order of degradation resistance of related pure minerals or end members is 4Mg(OH)2·2Al(OH)3·3H2O, 0.83CaO·0.67SiO2·1.83H2O, 0.67CaO·SiO2·1.5H2O, 6CaO·Al2O3·3SO4·32H2O, 6CaO·Al2O3·3SO4·30H2O, 1.33CaO·SiO2·2.17H2O, 3CaO·0.5Al2O3·0.5Fe2O3·0.84SiO2·4.32H2O, 3CaO·Fe2O3·0.84SiO2·4.32H2O, 1.5CaO·0.67SiO2·2.5H2O, Ca(OH)2. The order of mass decrease in set-cement degradation process is Ca(OH)2, calcium silicate hydrate solid solution, Si-hydrogarnet solid solution, ettringite solid solution, and M4AH10. The number of moles and the proportion of end member minerals changes and the quality of solid solution decreases, but the change is inconsistent with its relative degradation resistance.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |