松辽盆地红岗背斜油气的差异聚集

The Differential Hydrocarbon Accumulation in Long-Axis Anticline of Honggang Field,Songliao Basin

油气的重力分异作用使油气呈现出有规律的分布,一般高部位的构造圈闭为气藏,低部位的构造圈闭为油藏。但也有低部位构造圈闭为气藏而高部位构造圈闭为油藏的相反的情况,其原理为油气的差异聚集,国外有许多典型的实例。在松辽盆地红岗长轴背斜三个次级高点上,大量的试油结果证实,高台子油层Ⅲ砂岩组G13小层低部位的红131圈闭为气藏,较高部位的红7圈闭为油气藏,红16圈闭只含水。油气水的分布出现相反的现象。在详细分析其构造、储集层特征的基础上,认为G13小层具备油气差异聚集的基本条件,其油气分布能够用油气差异聚集原理进行很好地解释,是油气差异聚集的结果。红岗背斜G13小层是油气差异聚集原理的一个比较典型的实例。

The regular distribution of oil,gas and water due to gravitational differentiation tends to the fact that a gas reservoir forms in structural trap at higher part,while an oil reservoir in structural trap at lower part.However,there exist gas reservoir in trap at lower part and oil reservoir in trap at higher part due to differential hydrocarbon accumulation.Many typical cases have indicated this abroad.In long-axis anticline of Honggang field in Songliao basin,it is indicated from formation tests that Hong-131trap belongs to a gas reservoir which lies in lower sub-layer G13of Gaotaizi sand layer-III,Hong-7trap is an oil-gas reser-voir at higher part,and in Hong-16trap merely contains water which lies at the top.Based on detailed analyses of the structural and reservoir characteristics,it is shown that the basic conditions fordifferential hydrocarbon accumulation could appear in layer G13and can be used for well interpreting its oil-gas distribution.So the sub-layer G13is found to be as a first and typical case of the differential hydrocarbon accumulation in China.