稠油油藏注聚主要影响因素实验研究

针对渤海典型稠油油藏的非均质特征,建立内置微电极二维纵向非均质物理模型。通过含油饱和度测量技术进行了稠油油藏注聚主要影响因素实验研究,考察了油藏纵向非均质性、注入速度、注入黏度对聚驱剩余油分布规律及开采效果的影响。实验结果表明:对于纵向非均质稠油油藏,随着渗透率级差增加,注聚效果变差,剩余油主要富集在中、低渗透层。提高注入速度等同提高了注采压差。当压力梯度大于中、低渗透层启动压力梯度以后,才能动用中、低渗透层油。为了增加中、低渗透油层的动用程度,可以考虑适当缩小井距或者通过封堵高渗层,提高中、低渗层注采压差。对于非均质严重的稠油油藏,考虑到油层的实际条件,单纯靠增加体系黏度不能满足流度控制需要,必须通过调、堵等措施才能达到流度控制的目的。

Experimental Study of Main Influence Factors of Polymer Injection in Heavy Oil Reservoir

Aiming at the heterogeneous characteristics of Bohai typical heavy oil reservoir, we built two-dimensional longitudinal heterogeneous physical model where microelectrode is inside. By using oil saturation measurement technology, we study the main influence factors of polymer flooding in heavy oil reservoir. We also study the effect of reservoir vertical heterogeneity, injection rate and polymer viscosity on residual oil distribution and exploitation effect. The experiment results show that: with the increase of permeability, the polymer injection effect becomes worse and residual oil is mainly concentrated in the middle and low permeability reservoir in the longitudinal heterogeneous heavy oil reservoir. In order to make the injection profile more uniform and increase the producing degree in middle and low permeability reservoir, we should try to reduce permeability layer in the profile or adjust injection profile to solve the inner contradiction when combining the layers in the polymer flooding; to improve the injection rate is equivalent to improve injection production pressure difference. When the pressure gradient is greater than the starting pressure gradient in the middle and low permeability reservoir, oil in low permeability layers can be produced. In order to increase producing degree in middle and low permeability reservoirs, we can reduce well spacing or plugging high permeability layer to improve the injection production pressure difference. As for serious heterogeneous reservoir, considering the actual conditions of the reservoir, simply increasing the viscosity of the system cannot meet the need of mobility control, we must achieve the purpose of flow control by profiling, blocking and other measures.