有机质类型及演化特征对页岩气富集规律的影响

页岩气是生成并存储于页岩、泥岩中的一种非常规天然油气,具典型的源储一体特征。页岩气的成藏基本没有"运移""聚集"过程,因此页岩气富集规律成为页岩气研究的重点和难点。结合长宁地区现有勘探开发资料以及近年来页岩气勘探开发取得的新进展,分析有机质特征对页岩气富集规律的影响。页岩气的吸附量与泥页岩的有机质丰度具有明显的正相关关系,有机质丰度是生烃量和生烃强度的重要决定因素;不同的干酪根类型由于显微组分的差异而对页岩气具有不同的吸附能力;高成熟度能使有机质微孔隙增加,也能加快气体的流动,为页岩气的富集提供更多有利空间。

The Impact of Organic Matter Type and Its Evolution Characteristics on the Enrichment Regularity of Shale Gas

Shale gas, a kind of unconventional natural gas, is generated and stored in shale or mudstone, containing source reservoir characteristics.There are no typical features like′gather′and′migration′of conventional petroleum geology in shale gas, so the enrichment regularity of shale gas has been the key point of the research of shale gas. Based on the exploration and development data available in Changning area and the new progress of exploration and development in China recently, this paper focuses on the elaboration of the impact of organic matter characteristics on the enrichment regularity of shale gas.The adsorption of shale gas is positive correlation with organic matter abundance, and the index of organic matter abundance controls the production of the shale gas and the development cracks.Shale gas can be produced during all the time of organic matter evolution, but different kerogen has differ-ent effect on shale gas adsorption ability.High maturity can increase organic micropore and speed up the flow of gas, and can provide more favorable space of the enrichment of shale gas as well.