高渗含砾砂岩储层敏感性及注入水伤害研究

Research on sensitivity and water damage of high permeability gravel-bearing sandstone reservoirs

本文以西部某油田含砾砂岩储层为例,通过X衍射射线分析、物性测试、扫描电镜及岩心流动实验,从内因和外因两方面对油田注水开发过程中产生的储层伤害进行了研究。研究结果表明,研究区块具有较高临界盐度、中等偏弱水敏和弱速敏特征。在经过不同处理程度的注入水伤害评价实验中,将注入水驱替实验前后岩心的扫描电镜照片进行对比,发现储层中敏感性矿物的形态和分布变化不大,对渗流通道影响较小,认为储层伤害主要是来自注入水中的较高的悬浮物含量。建议该油藏在注水开发过程中,应提高注入水处理工艺水平,严格控制注入水中的悬浮物含量,从而减小储层伤害,改善注水开发效果。

In this paper, the formation damage caused by water injection during the process of water flooding is studied by X-ray diffraction analysis, physical property test, scanning elec- tron microscope and core flow experiments. The results show that the reservoir has high criti- cal salinity, moderate weak water sensitivity and weak velocity characteristics. In the experi- mental evaluation of formation damage of injected water with different degree of treatment, the scanning electron microscopy photos of the core was compared before and after core flow ex- periments. It was found that the morphology and distribution of the sensitive minerals in the reservoir changed little and had little effect on the seepage channel. It is considered that the reservoir damage is mainly from the injection of water in the higher suspended solids content. It is suggested that the water injection process should be improved during the development of water injection, and the content of suspended solid in water should be strictly controlled, so as to reduce reservoir damage and improve water iniection development effect.