关键词: 盆地模拟, 成岩史, 蒙皂石向伊利石转化, 热反应方程, 溶解沉淀方程, 数值模型

Abstract: There are two numerical models for theory analysis of smectite-illite transformation at present in the world, including the first-order thermal reaction equation and the dissolution-precipitation equation. The first-order thermal reaction equation has been widely introduced into basin modeling. This equation adopted the law of mass action, but did not completely follow the compound reaction. The thermal parameters were only related to temperature and burial time over 250℃. The dissolution-precipitation equation followed the compound reaction and was based on the mechanism of smectite dissolution in free pore water and subsequent precipitation of illite. This equation was related to not only temperature and burial time but also to the variety of rock matrix and pore fluid during sedimentary compaction. On the basis of the works of pioneer contributors, the dissolution-precipitation equation was improved and used in basin modeling. The corresponding module was programmed and successfully applied to several basins. The theory and practice proved that the dissolution-precipitation equation is better than the first-order thermal reaction equation.

Key words: basin modeling, diagenetic history, smectite-illite transformation, thermal reaction equation, dissolution-precipitation equation, numerical model