Y油田低渗透油藏高含水阶段提高采收率研究

Study on Enhanced Oil Recovery in High Water-cut Stage of Low Permeability Reservoir in Y Oilfield

低渗透砂岩油藏储量丰富,约占全国储量的2/3以上,开发潜力巨大。该类油藏具有孔渗条件差、储层非均质性强、吸水能力差等特点,开发后期油藏进入高含水阶段,存在水驱效果差、开发难度大、采收率较低等问题,因此亟需探究提高采收率的有效手段。以Y油田低渗透油藏为例,在地质模型和精细油藏描述的基础上,通过生产动态分析和剩余油表征,针对全区水驱储量控制程度低、油井含水高、注采井网不完善的问题,提出了精细注水、注气和水气交替等措施。通过数值模拟方法,对比不同措施的开发效果,优选最佳方案,预测实施调整方案15年后,全区采收率提高12%。该研究成果可为低渗透砂岩油藏高含水期的高效开发提供参考依据和借鉴。

Abundant reserves are possessed by low permeability sandstone reservoirs in China,accounting for over two-thirds of the national total,indicating substantial development potential.These reservoirs are characterized by poor porosity and permeability,strong reservoir heterogeneity,and low water imbibition capacity.During the later stages of development,reservoirs frequently enter a high water-cut phase,leading to challenges such as poor water flooding efficiency,increased development complexity,and lower recovery rates.Consequently,there is an urgent need to explore effective methods to enhance the recovery factor.The low-permeability reservoirs in Y Oilfield were taken as a case study in this research.Based on geological modeling and detailed reservoir characterization,through production dynamic analysis and residual oil assessment,challenges such as low control over water-flooded reserves,high water-cut in oil wells,and incomplete injection-production well networks were being addressed,measures including precise water flooding,gas injection,and alternating water and gas injection were proposed.Through the numerical simulation methods,the developmental effects of different measures were compared,the optimal scheme was selected,and it was predicted that,after implementing the adjusted plan for 15 years,the recovery factor of whole area could be increased by 12%.The research findings serve as a reference and a valuable resource for the efficient development of low-permeability sandstone reservoirs during the high water-cut phase.