松辽盆地南部高台子油层成藏动力学

Research on the Hydrocarbon Accumulation Dynamics of Gaotaizi Reservoir in the Southern Songliao Basin

以油气成藏动力学系统研究为核心,在松辽盆地南部油气成藏地质条件分析的基础上,对高台子油层现今流体势进行计算和古流体势恢复。结果表明:高台子油层古—今流体势在大安凹陷—长岭凹陷一带始终为一个高势带;高流体势带构成了盆地南部一级流体分隔槽,流体分隔槽以西流体势等值线形态简单,以东则较复杂。依据流体势场,在中央分隔槽以西划分出1—2个它源(自源)开放成藏动力系统,以东划分出2—3个它源(自源)开放(半封闭)成藏动力系统,每个成藏动力系统构成一个相对独立的汇聚单元。利用油气成藏动力系统分析结果,结合构造沉积演化及储层流体包裹体研究,分析了松辽盆地南部高台子油层的油气充注过程和聚集规律。发育于斜坡区和近凹陷隆起区的各类圈闭,由于流体势梯度大,有利于形成各类油气藏。

Based on the analysis of the geological conditions of hydrocarbon accumulation in the southern Songliao basin,the present fluid potential of Gaotaizi reservoir is calculated and the palaeo-fluid potential is recovered with the hydrocarbon accumulation dynamics systematic research as the core.The results show that the palaeo-present fluid potential of Gaotaizi reservoir is always high in the belt of Daan depression-Changling depression.The high-fluid potential belt constitutes the first-order separation trough in the southern Songliao basin.The fluid potential contours are simple to the west of the separation trough and complex to the east.Based on fluid potential field,1-2 allogenetic（authigenic）open hydrocarbon accumulation dynamic systems are divided in the west of the central separation trough,and 2-3 allogenetic（authigenic）opening （semi-closed） systems are divided in the east.Each hydrocarbon accumulation dynamic system constitutes a relatively independent of the aggregation unit.Applying the hydrocarbon accumulation dynamic system analysis results,combined with tectonic sedimentary evolution and reservoir fluid inclusion studies,the hydrocarbon charging and accumulation in the Gaotaizi reservoir is characterized.The various traps developed in the slope and near-depression uplift are conducive to the formation of various types of oil and gas reservoirs,because of their large fluid potential gradient.