油藏注水开发后期窜流通道定量识别方法

窜流现象是油藏注水开发后期提高采收率面临的技术难题。为了能够更精确地识别窜流通道的大小,提高水驱采收率,提出了一种利用动态数据定量研究窜流通道的方法。首先根据油井生产动态曲线识别水窜井,然后根据不同组合情况下注采井之间的相关系数来判断窜通关系,最后利用建立的窜通体积与注采量的关系式计算窜通体积。利用该方法对某区块57220井区的57217井进行了系统分析,并进一步分析了整个区块的水窜情况,得到了其窜流通道分布和对应窜通体积。研究发现,水窜的发生不仅仅局限于井组内,还可能发生在不同井组的注采井之间。窜流通道大小的准确确定,可为调堵措施的实施提供依据。 

Quantitative Identification of Breakthrough Channel in Water Flooding Reservoirs at Later Stage

Water breakthrough is one of the main barriers for EOR of reservoirs by water flooding at later stage.In order to enhance oil recovery in water flooding reservoirs,and to identify the breakthrough channels precisely,a method to study the water breakthrough channels quantitatively with dynamic data has been shown in this paper.First,water breakthrough wells can be identified through curves of dynamic data,and then,breakthrough relations can be determined according to the correlation factors between injection and production wells under different conditions.Lastly,breakthrough channel volumes can be obtained by building a model between breakthrough volume and injection-production rates.Well 57217 in Block 57220 in Karamay Oilfield has been analyzed by this method systematically.The distribution of water breakthrough channels of the whole block has been further analyzed and the volumes of the water breakthrough channels have been calculated.According to study,water breakthrough may be found not only inside a well group limitedly,but also can be found between wells in different injection-production well groups.The quantitative identification of water breakthrough channels provided a theoretical basis for measures of formation section control and water shutoff.