特低渗油藏注水时机对开发的影响

Influence of water injection timing on development in ultra-low permeability reservoirs

注水时机对油田的开发效果有着很重要的影响,研究确定特低渗透油藏注水时机,对延长油田高产稳产时间以及提高油藏采收率都十分必要。本文着重利用矿场资料统计的方法,对鄂尔多斯盆地已开发不同类型油藏的注水时机与产量变化关系、采出程度和含水关系、地层压力和产液量关系等进行了统计分析,总结出该类油藏的开发特征,同时简单分析了其机理。通过研究发现,特低渗透油藏不同的注水时机,开发效果迥然;安塞油田早期、同期、滞后和未受效四种情况,初期稳产阶段产量比例为4.27:2.3:1.87:1。因此,对于特低渗透油藏的开发应认真研究适宜的注水时机,尽可能实施早期注水。

The water injection timing is very important for development effect of an oilfield. The research of water injection timing of ultra-low permeability reservoir is necessary to prolong the period of high production and stabilized production or to enhance the recovery ratio. This article analyzes the relationships of water injection timing and production changes, degree of reserves recovery and water content, reservoir pressure and liquid producing capacity by using the statistical method on different types of developed reservoirs in Ordos Basin. Then we get the development characteristics of this kind of reservoirs. We also study the mechanism in this article. The study result indicates that the development effect would be different if the water injection timing is different. For the early stage, same stage, late stage and non-response waterflooding of Ansai Oilfield, the stabilized production ratio of the initial period is 4.27 ： 2.3 ： 1.87 ： 1. We should study the water injection timing and implement the early stage waterflooding as early as possible for the development of extremely-low permeability reservoirs.