玛湖凹陷斜坡区浅层油气地质条件及勘探潜力

Geological conditions and exploration potential of shallow oil and gas in slope area of Mahu Sag,Junggar Basin

准噶尔盆地玛湖凹陷斜坡区浅层(T2k-J)具有较大勘探潜力,为了研究其油气地质条件和成藏有利区的分布规律,开展了大量的录井、测井和岩心资料分析,基于三维地震资料解释,对斜坡区浅层进行了综合地质评价。结果表明:①玛湖凹陷斜坡区克拉玛依组、白碱滩组、八道湾组和三工河组等4套目的层的储层规模大,埋藏浅,物性好,具备形成集群式分布的岩性油气藏的条件;②研究区储盖组合配置较好,纵向上相互叠置,为集群式分布的岩性油气藏奠定了良好的储盖组合条件;③斜坡区断裂的发育为斜坡区浅层油藏提供了良好的油气运移通道;④研究区断块或断层-岩性圈闭均具有集群式分布的特征,且空间上叠置连片分布,成圈条件优越。浅层与深层油气富集区表现为"接力成藏"特征,具有一定继承性。该研究成果对玛湖凹陷斜坡区浅层的油气勘探具有指导作用。

Shallow layer(T2k-J)in the slope area of Mahu Sag in Junggar Basin has great exploration potential.In order to study the geological conditions of oil and gas and the distribution law of favorable area for reservoir formation,a large number of analyses of mud-logging,wire-logging and core data were carried out.Based on3 D seismic data interpretation,the shallow layers in the slope area were comprehensively evaluated.The results show that:(1)The reservoirs of Karamay Formation,Baijiantan Formation,Badaowan Formation and Sangonghe Formation in the slope area of Mahu Sag are characterized by large scale,shallow burial,good physical properties,and have the conditions to form lithologic reservoirs with cluster distribution.(2)The reservoir cap assemblage in the study area is well configured and vertically overlapped,which lays a good reservoir cap assemblage condition for lithologic reservoirs with cluster distribution.(3)The development of faults in the slope area provides a good oil-gas migration channel for shallow reservoirs in the slope area.(4)Fault blocks or fault lithologic traps in the study area have the characteristics of cluster distribution,and they are overlapped and contiguous in space,with superior conditions for trap forming.The shallow and deep oil and gas enrichment zones are characterized by"relay accumulation"and have certain inheritance.The research results have a guiding role for shallow exploration in the slope area of Mahu Sag.