南堡2号潜山注氮气提高采收率研究

Enhancing Oil Recovery Ratio by N 2 Injection in Nanpu No.2 Buried Hill

为了提高南堡2号潜山高含水油藏采收率,在剩余油研究的基础上,通过室内实验与数值模拟相结合,探索2号潜山注氮气提高采收率合理注入方式和注入参数。研究显示:南堡2号潜山注氮气能有效降低地层油黏度和密度,改善地层油流动性;氮气对地层油膨胀能力有限;合理注入方式为气水交替驱,合理注入参数为气水比1∶1。矿场实验揭示,当出现气窜迹象时,采用多段塞小剂量气水交替注入可有效防止气窜,是提高南堡2号潜山油藏采收率的有效方式。目前,通过实施注氮气,NP23-P2013井组累计增油3 200 t,投入产出比1∶3.6。

To enhance oil recovery ratio of the oil reservoir with high water cut in Nanpu No.2 buried hill,based on studies of remaining oil,the reasonable injection mode and injection parameters of N 2 are explored by combination of experimental study and numerical modeling.Research shows that:N 2 injection can reduce the formation oil viscosity and density effectively and improve the liquidity of formation oil;N 2 has limited capacity towards the inflation of formation oil.Reasonable injection mode is water and gas alternate injection,the injection parameter of gas water ratio is 1∶1.The field experiments reveal that multiple-slug and small-mount WAG injection can prevent gas channeling effectively.At present,the accumulative production of NP23-P2013 well group has increased 3200t and the input-output ratio is 1∶3.6.