Thermodynamic Calculation of Feldspar Dissolution and Its Significance on Research of Clastic Reservoir
详细信息
- 责任者：Huang Keke (State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation ; Institute of Sedimentary Geology ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Huang Sijing
- 刊名：Geological Bulletin of China
- 出版年：2009
- 卷期：28(4)
- 关键词：碎屑岩储集层 ; clastic reservoirs ; 长石族 ; feldspar group
- 页码：p.474-482
- 图表：2 illus., 3 tables, 20 refs.
- 分类号：1003
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
摘要
Based on the calculation of Gibbs free energy increment (ΔG)for the reactions involved dissolution of three end-members of feldspar (K-feldspar, albite and anorthite) to form kaolinite or illite. The thermodynamic characteristic of these processes under dif-ferent conditions of temperatures and pressures has been explored in this paper. The results indicate that K-feldspar, albite and anorthite conversion to kaolinite and illite respectively are all spontaneous reaction in diagenesis environment. The minimum of Gibbs free energy increment and high positive temperature effects involved in anorthite dissolution reaction demonstrated that it is most instable and is more easily to be decomposed under low tempterature. K-feldspar dissolution reaction shows the maximum Gibbs free energy increment and strong negative temperature dependence, which shows higher stabitity and high temperature solubility of K-feldspar. Albite dissolution reaction with moderate increment of Gibbs free energy is not affected obviously by temperature.