Thermodynamic Equilibrium of Calcite in Strata Environment and Its Application of Burial Karst Forcasting in Tahe Oil Field, Tarim Basin
详细信息
- 责任者：Ruan Zhuang (State Key Laboratory of Petroleum Resource and Prospecting ; China University of Petroleum ; Beijing 102249 ; China) ; Yu Bingsong
- 刊名：Journal of Jilin University
- 出版年：2011
- 卷期：41(4)
- 关键词：储层预测 ; reservoir prediction ; 埋藏成岩作用 ; burial diagenesis ; 方解石 ; calcite
- 页码：p.1020-1027
- 图表：4 illus., 2 tables, 25 refs.
- 分类号：1003
- 出版序号：664
- issnNo：ISSN1671-5888
- isbnNo：CN22-1343/P
摘要
According to the reaction equilibrium of CaCO3 and activity of Ca2+ in groundwater,the solubility of calcite in different temperatures and pressures could be calculated. The pH value and the temperature of solution are the main factors to control the solubility of calcite. The dissolving tendency of calcite could be judged by the Gibbs free energy. The condition with ΔG<0 in the solution is favorite to dissolution of calcite and that with ΔG>0 is favorite to deposit of calcite. The ΔG of groundwater in thirty-four wells are calculated, Tahe oilfield. The results show that: present groundwater conditions favor the dissolution of calcite, the calcite tends to dissolute more in west and south area. This water-rock reaction theory can be used to quantitative understand the burial karst tendency and support the reservoir evaluaterating.