有机质类型及演化阶段对泥岩盖层浓度封闭作用的影响

Influence of Organic Type and Its Evolution Stage on Concentration Sealing of Mudstone Caprock

付　广 薛永超 付晓飞

大庆石油学院

Daqing Petroleum Institute , Heilongjiang 151400 , P. R. China

在分析泥岩盖层浓度封闭机制及类型的基础上,研究了含有不同类型有机质的泥岩盖层在不同演化阶段的生油气特征及孔隙水的变化情况,确定了其存在相态,并分析了其在不同演化阶段的浓度封闭作用特征。结果表明:生化阶段和高成熟—过成熟阶段,含腐殖型和含腐泥型有机质的泥岩盖层均具有较强的替代封闭作用;低成熟—成熟阶段早期,2 种类型的泥岩盖层均具弱的替代封闭作用;成熟阶段高峰期—结束,含腐殖型有机质泥岩盖层具强的抑制封闭作用,而含腐泥型有机质泥岩盖层可能具有弱的抑制封闭作用或替代封闭作用。

Based on analysing formation mechanism and types of concentration sealing of mudstone caprock , this article studied the characteristics of oil and gas generation and pore water changes of mudstone caprock with different organic types in different evolution stages , and determined the phase of gas in porosity of mudstone caprock. According to this ,this paper analysed the characteristics of concent ration sealing of mudstone caprock with different organic types in different evolution stages. Considered the mudstone caprocks with sapropelic and humic organic matter own strong replacing sealing ability in biochemical stage and high mature and supermature stage. The mudstone caprock with humic organic matter owns strong rest raining sealing ability f rom high peak to stop period of mature stage. The mudstone caprock with sapropelic organic matter owns weak rest rainng sealing ability or replacing sealing ability.