二类油层聚驱注入相对分子质量匹配关系研究

研究了目标油层在水聚干扰相对较为严重的情况下，不同井组分别注入中、高相对分子量聚合物以后，依据现场资料分析总结出井组周围油井的见效情况、含水率变化、阶段采出程度，得到了二类油层井组合适的参数，以保证注入的聚合物的质量以及注入聚合物的效果，从而极大地提高采收率以及目标区块的开发效益。结果表明，该油层更适合注入1 200~1 600万相对分子量的聚合物，黏度应在30~50 mPa?s；在背景条件相近的情况下，中分更适合动用薄差油层，使该二类油层高聚合物质量浓度驱含水率下降幅度大，增加产油量的效果非常好，采取该技术可以提高采收率，较常规聚合物质量浓度高10%以上。

Study on the Matching Relationship of Molecular Weight in Polymer Flooding for Type II Reservoir

This article mainly discusses the target reservoir after injection of medium and high molecular weight polymer into different well groups under the condition of relatively serious water accumulation interference. Based on the analysis of field data, the effectiveness, water cut change and stage recovery degree of oil wells around the well group are summarized. The appropriate parameter setting for the second oil reservoir well group are obtained to ensure the quality and the effect of the injected polymer, thereby greatly improving the recovery rate and the development benefit of the target block. The results show that the oil layer is more suitable for injecting 1 200~1 600 million molecular weight polymers, and the viscosity should be in the range of 30~50 mPa?s; in the case of similar background conditions, the medium fraction is more suitable for the use of thin?difference oil layers, the high concentration of water in Class II oil reservoirs has a large decline in water cut, and the effect of increasing oil production is very good. The adoption of this technology can increase oil recovery, which is more than 10 percentage points higher than the conventional concentration.