注水开发中濮城油田储集层性质变化的研究

Variations of Reservoir Properties During Walerflooding in Pucheng Oilfield

濮城油田主要产层已进入高含水及特高含水阶段。储集层在注入水的长期冲洗下 ,孔隙度大、渗透率高的地层 ,注水后孔隙度、渗透率都将增大 ;而岩性致密的储层 ,注水后孔隙度、渗透率基本保持不变或略有下降。随着水洗程度的增加 ,砂岩颗粒表面的粘土被水冲掉或冲散 ,颗粒表面光滑 ,岩石表面润湿性由亲油向亲水方向转化。长期受注入水的冲刷 ,相渗透率曲线表现出两相流跨度较小 ,水相渗透率急剧上升的特点。储集层在注水开发过程中 ,水沿着高渗透带推进是很明显的规律 。

The productive reservoir in Pucheng oilfield is in the periods of high and super high water cut Under the conditions of prolonged washing in reservoir, porosity and permeability increase in a high porosity and high permeability reservoir after water injection; the porosity and permeability remain constant or decrease slightly after water injection in a tight reservoir With the increase of flushing, clay on the surface of sandstone grains is washed away or scattered Wettability on rock surface can change from oil wet to water wet Facies permeability curve presents that the span of two phase flow is low and water facies permeability rises up quickly because of prolonged flushing in water injection During the waterflooding, water drives along the high permeability zone of reservoirs obviously, resulting in the zone watered out