滨里海盆地S区块三叠系油藏类型及成藏模式

Reservoir types and hydrocarbon accumulation models of Triassic formation in S block of pre-Caspian basin

受盐隆上拱和构造运动影响,滨里海盆地S区块三叠系在纵向上不同层位发育不同类型的圈闭,形成相应不同类型的油藏:上三叠统主要形成盐顶断鼻、断块油气藏和岩性油气藏,中三叠统主要形成盐檐油气藏和盐边遮挡油气藏,下三叠统主要形成地层超覆油气藏。中三叠统是三叠系最有利的成藏层位:埋藏适中、保存条件好、储层发育且物性较理想、圈闭类型多且与盐下油气生成与运移的时空匹配较合理。在三叠系5种成藏模式中,中三叠统盐檐油气藏成藏模式对油气勘探最具有指导意义。

Different trap types are formed in the different strata of Triassic in the S Block of pre-Caspian basin impacted by the up-lift of the salt swell and the movement of tectonic, resulting in different reservoirs. Faulted noses, block reservoirs and lithologic res-ervoirs on the top of the salt swell are the main reservoirs in the upper Triassic. Salt eave reservoirs and salt rim screened reservoirs are the main reservoirs in the middle Triassic. Stratigraphic overlap reservoirs are the main reservoirs in the lower Triassic. The middle Triassic is the most favorable horizon for hydrocarbon accumulation for the moderate depth, good preservation conditions, developed reservoirs and good properties, while with trap variety and reasonable match in the time and space with the oil generation and migration from the pre-salt strata. The salt eave hydrocarbon accumulation model of the middle Triassic is the best for oil ex-ploration out of the 5 models of the Triassic.