周期停层在聚驱控水提效中的应用

Application and Effects of Cyclic Shutoff Injection Interval for Controlling Water Cut to Improve Efficiency in Polymer Flooding

聚驱进入后期开发阶段,低渗透率油层动用比例降低,聚合物溶液沿厚油层的底部产生"舌进"现象,油井含水回升速度快。为了有效地控制含水回升,改善注聚后期开采效果,选取5个以注入井为中心的典型井组。对厚油层实施周期停层,利用停层后渗流压力场重新分布,使高低渗透率油层之间产生压差,驱动低渗透率油层剩余油向高渗透率油层流动,提高驱油效率。方案实施后,取得了一定的经济效益。

When polymer flooding comes into late development period, production ratio of low permeability reservoir declines, polymer solution produces phenomenon of 'tongue moving' along the bottom of the thick oil layer and water cut in oil wells increases rapidly. In order to control water cut increasing and improve the polymer flooding effects in late development, cyclic shutoff is implemented in 5 typical injection wells. Redistribution of percolation pressure field is utilized to produce differential pressure between low and high percolation reservoirs and drive residual oil in low permeability reservoir to flow into high permeability reservoir, consequently improve the oil flooding efficiency. After this strategy is implemented, cumulative oil production is increased by 360 tons and economic benefit is produced by 601.26 thousands yuan.