沉积岩中无机CO2热模拟实验研究

结合三水盆地的地质特点，分析了无机CO₂热模拟实验研究的可能性，进行了不同条件下的模拟试验和相关的分析测试，提出了无机CO₂生成量和转化率的概念和计算方法。从实验结果来看：含有一定量碳酸盐矿物的沉积岩，在一定温度下可转化形成相当数量的无机CO₂，无机CO₂转化率越高，岩石中碳酸盐矿物越容易转化生成无机CO₂；相同热成熟度条件下，Ⅱ型干酪根生成有机CO₂的量较Ⅲ型的少；CO₂中碳同位素与CO₂的成因密切相关，随有机质热成熟度的增加，同种类型有机质生成的有机CO₂相对富集¹³C；无机CO₂较有机CO₂的碳同位素明显富集¹³C，随水介质的pH值降低，无机CO₂气含量、模拟温度及时间的增加，无机CO₂相对富集¹³C。实验研究结果为CO₂成因研究及其资源评价提供了实验依据。

A RESEARCH ON THE INORGANIC CARBON DIOXIDE FROM ROCK BY THERMAL SIMULATION EXPERIMENTS

Combining with the geological characteristics of Sanshui basin, the author analyses the possibility to do thermal simulation experiments of inorganic carbon dioxide, has done many experiments under different conditions and relative determinations, gives the concepts of yield quantity and conversion rate of inorganic carbon dioxide in sedimentary rocks and works out the method to calculate them . The experimental results show: the sedimentary rocks that contain carbonate minerals can convert into a number of inorganic carbon dioxide, the higher the conversion rate of inorganic carbon dioxide is, the easier the carbonate minerals in the sedimentary rock convert. Under the same thermal maturity, the quantity of organic carbon dioxide yielded in kerogen of style Ⅱ is smaller than that yielded in kerogen of style Ⅲ. There is a close relation between the carbon isotope and origin of carbon dioxide. Along with the increase of thermal maturity of organic matter, the ¹³C is getting more and more in organic carbon dioxide yielded by the same style organic matter. The ¹³C in inorganic carbon dioxide is enriched obviously than that in organic carbon dioxide. The ¹³C in inorganic carbon dioxide is enriched as the pH of water added in the experiment decreases and the content of inorganic carbon dioxide in the yielded gas, the experimental temperature and time increase. All these experimental results give proofs of simulation experiments for the research on the origin of carbon dioxide and its resources evaluation.