油气田开发措施效果定量评价的累计产量曲线法——以渤海湾盆地雁翎油田注氮气试验区为例

Cumulative production curve method for the quantitative evaluation on the effect of oilfield development measures:A case study of the nitrogen injection pilot in Yanling oilfield,Bohai Bay Basin

为了定量评价油气田开发措施的效果,以Arps产量递减理论为基础,推导出累计产量与生产时间的乘积Npt与生产时间t的直线关系式,建立了定量评价开发措施效果的累计产量曲线方法。以雁翎油田注氮气试验区为例,计算了注氮气前后的可采储量,通过可采储量的变化,定量评价了注氮气对开发生产的实际效果。递减曲线晚期形态的相似性分析表明,该方法不受递减类型限制,Npt-t的关系曲线在开发晚期均趋于一条直线。累计产量曲线法不仅适用于单井,也不受油藏和气藏类型的限制。配合导数曲线进行诊断,不仅反映了Npt-t直线段斜率的微观变化,而且反映了开发中可采储量的变化以及储量动用的过程。利用累计产量曲线法对雁北注氮气试验区进行单井定量评价,结果表明:注氮气使位于潜山腰部的油井产能明显增加,顶部油井产能降低,注氮气对边部油井产能影响较小。

To evaluate the effect of oilfleld development measures quantitatively, based on the theory of Arps production decline, this study deduced a linear relation between the product of cumulative production with production time （Npt） and production time （t）, and established the cumulative production curve method for quantitative evaluation on the effect of development measures. The nitrogen injection pilot in Yanling oilfield was taken as an example to calculate the recoverable reserves before and after the nitrogen injection, and through the variation of recoverable reserves, the effect of the nitrogen injection on actual production was quantitatively evaluated. Similarity analysis of decline curve shape in the late period shows that the method is not restricted by decline types and the relationship curve between Npt and t in the late development is always tending to a straight line. The cumulative production curve method is not only suitable for single wells but also not restricted by reservoir types. Combined with derivative curve in diagnosis, it reflects the microscopic variations of the slope in the straight line segment and the variations of recoverable reserves and the process of reserve producing. The single wells in the ~anbei nitrogen injection pilot were evaluated quantitatively using the cumulative production curve method , the results show that： the nitrogen injection causes obvious productivity increase of the oil wells in the hillside of the buried hill, productivity decrease of the oil wells at the top of buried hill, and little influence on the productivity ofoil wells in the margins of burial hill.