高含水砂岩油藏降压开采数值模拟研究方法

中高渗砂岩油藏在注水开发高含水后期,利用油藏降压开采作为开采转换方式措施是提高水驱采收率的重要方法,关键是如何依据油藏的静、动态等条件与状况,量化给出降压开采的时机、地层压力降落的程度、含水率与采出程度的相关关系来最大限度的取得最高水驱采收率。在研究与综合分析国内外高含水油田油藏数据的基础上,分别按正韵律、反韵律、复合韵律建立计算模型,设计了42种数模计算方案,并以某油田断块为重点,应用CMG公司的IMEX黑油模拟器,设计并计算研究了26种数模计算方案,取得了一定的研究成果,为研究砂岩油藏高含水后期开发时实施降压开采措施提供了方法与认识,并对断块的生产历史和数值模拟研究计算结果与计算模型的计算结果进行验证比较,结果可以看出两者有很好的可比性。

Numerical Simulation Approach of Blowdown of Sandstone Reservoirs in High Watercut Stage

When medium or high permeability sandstone reservoirs are produced in high water-cut stage,using blowdown as production conversion mode is an important way to increase the recovery ratio of water drive.In order to get the highest oil recovery factor of water drive,the key is how to make sure the opportunity of blowdown,the degree of pressure breakdown and the correlation of water cut and a ratio of total oil produced to OOIP by using the reservoirs' static and dynamic conditions and status.On the base of synthetically analyzing data about high water-cut sandstone reservoir in China and abroad,three geological models of positive rhythm,inverted rhythm,and composite rhythm were established,42 simulation plans were designed.IMEX black oil simulator of CMG Co.was used in some block oilfield,to design and calculate 26 simulation plans.Comparing the results of simulation plans of block with the results of the calculation model,the result showed that they were comparable well.This paper got some research productions,and provided some methods to resolve the problems of developing medium or high permeability sandstone reservoirs in the high water-cut period.