CO2和CH4的转化与气田的关系之我见

长期以来，在石油地质研究领域对CO₂与CH₄的转化关系及其转化成因尚无统一的定论。一般只将CO₂作为生油还原环境的参数指标之一。因此在油气田勘探研究中，常将CO₂在储存空间的保存完好性作为判定生、储油气层保存完好性的指标，这样CO₂在油气田勘探阶段中仅作为寻找油气藏的一个线索。但在如下几种条件：①存在CO₂催化剂（触媒剂）；②存在H₂及H₂的化合物；③具备一定的温度和压力条件；④处于特定的保存条件下，则CO₂可以转化为CH₄及烃类，或者CH₄及烃类能够转化为CO₂。由此认为，CO₂可作为勘探开发大气田的指示气体，而且在发现有高含量和高产量的CO₂气井地区内，有可能勘探到丰富的天然气资源。

A POINT VIEW ON THE RELATIONSHIP BETWEEN GAS FIELD AND THE TRANSFORMATION OF CARBON DIOXIDE(CO2) AND METHANE (CH4)

There are not consistent opinions on how and why CO2 or CH4 was transformed each other in the field of petroleum geologic studies up till now. Because CO2 is usually regarded as one of indexes for restoring crude oil environment, in exploratory studies in oil and gas fields, whether CO2 is found to be kept well or not in the reservoirs can indicate if the generating and accumulating formations were kept in good condition. That is to say, CO2 is only taken as one of major clues for discovering oil and gas reservoirs at the exploration stage of oil and gas fields. CO2 can be transformed into CH4 or some other hydrocarbons, and vice versa, under these conditions as follows: ①catalyst, ②H2 or hydride, ③certain temperature and pressure, and ④good sealing environment. This paper suggests that CO2 should be regarded as an indicating gas for exploring and developing large gas fields, rich natural gas resource should be explored and discovered in those areas where high content or high production of CO2 is found in those gas wells.