自旋回和异旋回的识别及其在油藏地层对比中的作用

在分析自旋回、异旋回的发育背景、控制因素、存在的级别和范围的基础上,探讨自旋回的识别方法和自旋回对异旋回的改造和影响。结果表明:低频的层序或旋回(1～4级)是受基准面变化产生的异旋回,中频的层序或旋回(5～6级)是受自旋回改造或干扰强烈的异旋回,高频层序或旋回(7级以上)属于自旋回;自旋回一般破坏异旋回的特征,使地层对比变得困难,但可以通过垂直物源方向和平行物源方向的对比剖面相互校对进行识别;特征明显的、分布范围广的事件性沉积(自旋回)可以在小层对比中起到正面作用,在油藏级别的地层对比过程中,由于地震剖面分辨率低,所起的作用很小,必须建立对比模式。

Recognition of auto-cycle and allo-cycle and its role in strata correlation of reservoirs

On the basis of the analysis of the developing background,controlling factors and the scale of auto-cycle and allo-cycle,the recognition method of auto-cycle and the effects and alternation of auto-cycle on allo-cycle were discussed.The results show that the lower frequency scale sequence or cycle(1-4 scale) are allo-cycle produced by base level change,middle frequency scale sequence or cycle(5-6 scale) are allo-cycle reformed or highly effected by auto-cycle,high frequency scale sequence or cycle(higher than 7 scale) are auto-cycle.The characteristics of allo-cycle are frequently destroyed by auto-cycle,which makes it difficult to do correlation according to allo-cycle.But the auto-cycle can be recognized by correlating the correlation profiles which are parallel and perpendicular to the sedimentary source direction.The characterized and widely spread event deposits(auto-cycle) are important to the high frequency scale strata correlation.Because the resolution of seismic profile is lower,its role in the strata correlation of reservoir scale is small,so correlation models are needed to be developed.