基于渗流屏障的底水油藏精细注水研究与应用

Research and Application of Fine Water Injection in Bottom Water Reservoirs Based on Seepage Barriers

针对底水稠油油藏注入水在正韵律作用下驱油效果差、大部分注入水无效循环等问题,对影响底水油藏注入水驱油的原因进行了分析,创新性地提出了依托隔夹层层内分段注水的底水油藏注水新模式,并利用数值模拟、正交设计及多元回归等方法对各层各段注水量进行了优化。结果表明,影响底水油藏注入水驱油效果差的原因主要是隔夹层上部和下部吸水量极度不均,引起注采井间或水平井跟趾端驱油效果差;层内分段注水实现了稠油底水油藏从“注水保压”向“注水驱油”的转变。现场试验井组增油效果明显,日增油20 m 3/d,实现了底水油藏注入水驱油,将底水油藏注水由“注够水”转变为“有效注水”。

Aiming at improving the poor water flooding effect of the heavy oil reservoir with bottom water,and solving problems of invalid water injection cycle,the reasons of water displacing oil injection effects on reservoir are analyzed,and the innovation in the new reservoir water injection mode is put forward for the first time by using numerical simulation,orthogonal design and multiple regression,based on isolation layer clamp sub injection.The method was optimized for each layer of each water injection.The results show that the poor effect of water flooding in oil reservoir with bottom water injection is mainly due to the fact that the upper and lower water absorption was extremely uneven,which resulted in the effect difference between wells or horizontal wells with toe displacement.Heavy oil reservoir with bottom water is transformed from the“water pressure”to“water flooding”in the sub injection.The oil increasing effect is obvious in the field test well group,reaching daily oil 20 m 3/d,which realized water flooding of the bottom water reservoir,changing the water bottom water reservoir from“enough water injection”to“water injection”.This innovatinginjection mode has an important guiding significance in the injected water flooding reservoir with bottom water,which will also stabilize oil control water and make a great contribution.