Abstract: In order to solve the technical problem of injected fluid channeling in offshore oilfields,the basic performance evaluation of plugging agent,core hole plugging rate and the large⁃scale dominant channel treatment experiment of "plugging + profile control" oil increase and precipitation effect was carried out in Bohai reservoir. The results show that the blocking rate of blocking agent for large⁃scale dominant channel is higher than 90%,which indicates that it can meet the technical requirements of blocking large⁃scale dominant channel in Bohai reservoir.Combining the large⁃scale dominant channel plugging technology with chemical profile control and flooding technology,the dual effects of macro and micro fluid flow diversion can be obtained,and the effect of oil increase and precipitation is very obvious.Compared with hydrophobically associating polymer solution,although the viscosity of Cr3+ polymer gel is relatively low,the polymer molecular aggregates in Cr3+ polymer gel have "intramolecular" cross⁃linking structure characteristics,and have better compatibility with reservoir pores,which can establish an effective displacement pressure gradient in deep core,resulting in better fluid diversion effect and larger recovery.

Key words: Reservoir in Bohai, Large size advantage channel, Blocking agent, Steming ratio, Shunt rate, Recovery efficiency, Mechanism analysis

摘要： 为解决海上油田注入液窜流技术难题，以渤海油藏为研究对象，开展了封堵剂基本性能评价、岩心孔眼封堵率和封堵+调驱增油降水效果的大尺寸优势通道治理实验研究。结果表明，封堵剂对大尺寸优势通道的封堵率高于90%，说明它可以满足渤海储层内大尺寸优势通道封堵技术要求。将大尺寸优势通道封堵技术与化学调驱技术相结合，可以获得宏观和微观液流转向双重效应，增油降水效果十分明显。与疏水缔合聚合物溶液相比较，尽管Cr3+聚合物凝胶黏度较低，但由于Cr3+聚合物凝胶内聚合物分子聚集体具有“分子内”交联结构特征，与储层孔隙配伍性较好，能够在岩心深部建立起有效驱替压力梯度，因而液流转向效果较好，采收率增幅较大。

关键词: 渤海油藏, 大尺寸优势通道, 封堵剂, 封堵率, 分流率, 采收率, 机理分析