鄂尔多斯盆地低渗砂岩油藏面临着严重欠注、增注措施有效期短等问题，这些因素共同导致了油藏水驱开发效果较差。为了提高欠注井注入能力，根据鄂尔多斯盆地西部欠注严重区块的地质、注入水质等资料，分析了欠注严重区的整体注入情况，探讨了地质与注入水质对欠注的影响规律，选取了两大类、9项影响注水效果的因素，基于Spearman（斯皮尔曼）相关性分析法计算了欠注程度与各影响因素的相关系数。结果表明：注入水质与地层的相互作用具有积累效应，在长期注水过程中导致注入压力逐渐升高，进而影响油藏注入量。以鄂尔多斯盆地西部长8段采出水回注区为例，相关系数为悬浮物含量>含油量>中值孔喉半径>变异系数>悬浮物粒径。通过分析相关性及现场数据，针对性提出了欠注治理建议，以改善注水效果。

Low-permeability sandstone reservoirs in the Ordos Basin face significant challenges, such as severe water injection deficiencies and short effective durations of enhanced injection measures, leading to poor water flooding development performance. To improve the injection capacity of deficient wells, geological and injection water quality data from severely deficient areas in the western Ordos Basin were analyzed. The overall injection situation of these areas was examined, and the influence of geological factors and injection water quality on injection deficiencies was explored. Nine factors affecting water injection effectiveness were selected, divided into two major categories. Using the Spearman correlation analysis method, the correlation coefficients between injection deficiencies and these factors were calculated. Results indicated that the interaction between injection water quality and formations exhibited cumulative effects, leading to a gradual increase in injection pressure during prolonged water injection, ultimately reducing reservoir injection rates. Taking the Chang-8 reservoir re-injection area in the western Ordos Basin as an example, the correlation coefficients ranked as follows suspended solids content > oil content > median pore throat radius > variation coefficient > suspended particle size. Based on correlation analysis and field data, targeted recommendations for mitigating injection deficiencies were proposed to improve water injection performance.