优势渗流通道对动态特征及剩余油影响研究

Influence of dominant seepage channels on dynamic characteristics and remaining oil

渤海X油田由于平面、纵向矛盾不断加剧,形成优势渗流通道,存在注入水无效循环现象。为解决此问题,提高油田开发效果,本文利用数值模拟分析优势渗流通道的形成对动态开发特征及剩余油分布规律的影响。研究结果为,形成优势渗流通道后注入端表现为注入压力下降、注水量上升吸水剖面严重不均;采出端表现为井底压力升高、产液量产水量急剧上升、水淹严重;反韵律油藏底部剩余油更加富集;正韵律油藏顶部剩余油更加富集;渗透率级差较大时,底部剩余油富集;渗透率级差较小时,重力作用明显,顶部剩余油富集。正韵律储层不论级差大小,均为顶部层段剩余油富集;注水井与采液强度较高的油井之间形成优势渗流通道,注入水沿优势渗流通道无效循环,剩余油在采液强度小的油井富集。

Due to the increasing horizontal and vertical contradictions in Bohai X oilfield,the dominant seepage channel is formed,and the phenomenon of ineffective injection water circulation exists.In order to solve this problem and improve the development effect of oilfield,numerical simulation is used to analyze the influence of the formation of dominant seepage channel on dynamic development characteristics and remaining oil distribution.The results show that the injection pressure decreases and the water injection increases at the injection end after the formation of the dominant seepage channel,and the water injection profile is seriously uneven.At the production end,the bottom pressure is increased,the liquid production and water production are sharply increased,and the water flooding is serious.The remaining oil at the bottom of the reverse rhythm reservoir is more abundant,the remaining oil at the top of the positive rhythm reservoir is more abundant.When the permeability difference is large,the remaining oil at the bottom is rich.When the permeability difference is small,the gravity effect is obvious and the remaining oil at the top is enriched.In positive rhythm reservoir,the residual oil is enriched in the bottom zone regardless of the gradient.The dominant seepage channel is formed between the water injection well and the oil well with high production strength,and the injected water circulates ineffectively along the dominant seepage channel,and the remaining oil is enriched in the oil well with low production strength.