基于量化参数的储层非均质性分布规律研究——以涠西南凹陷为例

Distribution regularity research of reservoir heterogeneity based on quantitative parameters:a case study of Weixinan Sag

储层非均质性的分布规律是影响油藏天然能量的主要地质因素,如何量化储层非均质性对油田开发的影响,这一直是地质研究者关注的重要问题。文中以涠西南凹陷古近系陆相三角洲为研究对象,利用工区内大量的基础数据,总结了储层非均质性分布规律,确定了储层单砂层厚度和韵律指数中值是表征储层平面及纵向非均质性的主要参数;根据单砂层厚度的差异,建立了储层连通率与注采井距的关系,明确了该区不同三角洲前缘类型的合理注采井距范围;结合储层非均质性主要表征参数,优化了不同油藏类型区域的采收率动态预测公式,计算采收率与实际采收率吻合度达到80%以上。该研究方法现场应用效果较好,可为后续油气田开发井网的调整部署提供依据,具有一定的适用性和推广性。

Distribution regularity of reservoir heterogeneity is the main geological factor affecting natural energy of the reservoir.How to quantify the influence of reservoir heterogeneity on oil field development has always been an important problem concerned by geological researchers.Taking the Paleogene continental delta in Weixinan Sag as the research object,using the large number of basic data in the work area,this paper summarizes the distribution regularity of reservoir heterogeneity,determines that the single sand layer thickness and median rhythm index are the main parameters to characterize horizontal and vertical heterogeneity of the reservoir;according to the difference of single sand layer thickness,the relationship between reservoir connectivity and injection-production well spacing is established,and the reasonable injection-production well spacing range of different delta front types in this area is defined;combined with main characterizations of the reservoir heterogeneity,the dynamic prediction formula of recovery efficiency in different reservoir areas are optimized,and the coincidence degree of calculated recovery efficiency and actual recovery efficiency is over 80%.This research method has good feild application effect,which can provide a basis for the adjustment and deployment of development well pattern,and has certain applicability and generalization.