W低阻油藏高不动水饱和度的成因及对低阻油层的影响

W油藏Z1油组为高孔低渗低阻油藏,低阻油层的地质成因复杂多样。该文针对Z油组的储层发育特征,统计了储层的不动水饱和度,分析了低阻层段Z1油组的高不动水饱和度的成因,以及不动水饱和度与油层电阻率的关系。通过研究发现,形成低阻层段Z1油组高不动水饱和度主要原因是储层细颗粒含量高,储层孔隙结构差、细微孔喉体积百分数高,以及岩石的亲水性。地层电阻率随着不动水饱和度的增高而降低。因此,高不动水饱和度是影响W油藏Z1油组低阻的重要原因之一。

GENESIS OF HIGH IMMOBILE WATER SATURATION IN THE W LOW RESISTIVITY RESERVOIRS AND ITS INFLUENCE ON THE LOW RESISTIVITY RESERVOIR

The reservoir of Z1 oil group in W Oilfield has low resistance,high porosity and low permeability.The low resistivity of the reservoir was caused by many geological reasons.In this paper,for the reservoir characteristics of Z oil group,statistics of the reservoir of immobile water saturation has been done,and the genesis of high immobile water saturation in the Z1 oil group in the W Low resistivity reservoirs,as well as the relationship between the immobile water saturation and reservoir resistivity has also been studied.Through the study,in low resistivity layer segment of Z1 oil group,it is found that the main reasons forming a highly immobile water saturation are high levels of fine particles of the reservoir,Poor pore structure of reservoir,Slightly higher percentage of fine pore and throat volume,and the rock hydrophilic.The formation resistivity increases as immobile water saturation decreases.Therefore,high immobile water saturation is one of the important reasons affecting the low resistivity of the Z1 oil group in the W oil reservoir.