Abstract:

Based on analyses of the cores，casting thin sections，porosity and permeability data as well as log data，this work summarises the carbonate reservoir characteristics of the Triassic Feixianguan Formation in Longgang Gas Field，Sichuan Basin.The research shows porous and permeable reservoirs are mainly dolostones，especially oolite dolostone，which are preliminary considered to be formed by dolomitization short after deposition(supposedly dorag dolomitization).Combined with regional geology data，the research suggests that the relative sea level fell in oscillation during the Feixianguan Age，which had important control on early stage dolomitization and two cycles of dolomitization formed in the perpendicular direction: each lower part of the Member 2 and 3 of Feixianguan Formation，where reservoirs with high quality developed.

Key words: Sichuan Basin, Longgang Gas Field, Feixianguan Formation, dolostone, diagenesis

摘要：

根据岩心、岩石铸体薄片、岩石物性分析化验资料并结合测井资料，对四川盆地龙岗气田三叠系飞仙关组碳酸盐岩储集层特征进行了研究。结果表明，研究区飞仙关组孔隙较发育、物性较好、能作为优质储集层的基本上都是白云岩类，尤其是鲕粒白云岩。初步认为这类鲕粒白云岩的形成主要与早期白云化作用（可能为混合水白云化）有关。结合区域地质背景，认为飞仙关期相对海平面呈振荡下降，其对早期白云化有重要控制作用，并在垂向上形成飞三1、飞二1两个白云化旋回，而优质储集层主要发育于这两个旋回中。

关键词: 四川盆地, 龙岗气田, 飞仙关组, 白云岩, 成岩作用

CLC Number: 

• TE122.2