酒东油田注入水对岩心渗透率的损害率实验

酒东油田注水井近井地带易堵塞，严重影响了该油田的采收率。为了研究酒东油田注水井堵塞原因，对其注入水主要水质指标进行了测试分析，并通过岩心驱替实验量化分析了注入水水质指标对岩心渗透率的损害程度。首先，采用单因素分析法开展了注入水矿化度、悬浮物含量、悬浮物粒径、含油量对岩心渗透率的损害率实验，然后根据单因素实验结果设计正交实验，通过正交实验研究了矿化度、悬浮物含量、悬浮物粒径、含油量协同作用对岩心渗透率的损害率，并对正交实验后的岩心进行扫描电镜分析，进一步明确了注入水对岩心的损害情况。由正交实验结果可知，悬浮物含量对岩心渗透率的损害程度最大，其次是悬浮物粒径和矿化度百分比，含油量对岩心渗透率的损害程度最小。当模拟注入水矿化度百分比90%、悬浮物含量8 mg/L、悬浮物粒径2 μm、含油量6 mg/L时，岩心的渗透率损害率最低。

Experimental study on the core permeability damage rate resulted from the injected water of the Jiudong Oilfield

In the Jiudong Oilfield, the immediate vicinity of water injection well tends to suffer blockage, which seriously impact the recovery factor of the oilfield. In order to investigate the reasons for the formation of the blockage in the water injection wells of the Jiudong Oilfield, the main water quality indexes of the injected water were tested and analyzed, and the core permeability damage degree resulted from the water quality indexes of injected water was quantitatively analyzed by conducting core displacement tests. Firstly, the core permeability damage rates resulted from the salinity, content of suspended matter, particle size of suspended matter and oil content of injected water were tested by means of the single-factor analysis method. Then, the orthogonal experiment was designed based on the single-factor test results. In the orthogonal experiment, the core permeability damage rate caused by the synergetic effect of salinity, content of suspended matter, particle size of suspended matter and oil content was analyzed. In addition, the cores experiencing the orthogonal experiment were analyzed under scanning electron microscope to further clarify the damage of injected water to the cores. The orthogonal experimental results show that the core permeability damage degree resulted from the content of suspended matter is the highest, which is followed by the particle size of suspended matter and the salinity, and that from the oil content is the lowest. And the core permeability damage rate is the minimum when the salinity of the simulated injected water is 90%, the content of suspended matter is 8 mg/L, the particle size of suspended matter is 2 μm and the oil content is 6 mg/L.