辽河油田高3618区块火线预测及注采参数优化

Fire Front Prediction and Injection⁃Production Parameter Optimization for Block Gao 3618,Liaohe Oilfield

辽河油田高升稠油油藏高3618区块受储集层强非均质性、井间干扰、孔喉堵塞等影响,火线推进不均匀,火驱效益低,为此,通过火驱物理模拟实验,明确原油不同氧化阶段的温度界限,利用阿伦尼乌斯方程修正动力学参数,在基础井网上建立井间连通性模型,定量表征注采井间连通程度。并用高温气体示踪剂模拟方法验证连通性模型合理性,两者结合表征火线的运移轨迹,拟合精度提高到85%。通过数值模拟方法优化注采参数来调控火线,减缓气窜,增大了火驱波及系数,提高了原油采收率。如I5-0151C2井与I51-156井初始日注气量均为10000 m^(3),I5-0158C井为10500 m^(3),注气井月增注气量3000 m^(3),水平井定液量100 m^(3)/d,参数优化后能够有效维持火线均匀推进,火驱波及系数扩大了8.74%,采收率提高了6.37%。

Affected by factors such as reservoir heterogeneity,well interference and pore blockage,the fire front advances unevenly,and results in unsatisfactory fire flooding development of the Block Gao 3618 in Gaosheng heavy oil reservoir of Liaohe oilfield.Therefore,physical experiments on simulating fire flooding process were carried out to understand the temperature limit of crude oil in different oxidation stages,kinetic parameters were revised using the Arrhenius equation,and a well connectivity model was established on the basic well pattern to quantitatively characterize the connectivity between injection and production wells.The rationality of the connectivity model was verified through hightemperature gas tracer simulation.The physical experiments and the model were joined together to characterize the moving trajectory of the fire front,making the fitting accuracy increase to 85%.After optimizing the injectionproduction parameters based on numerical simulation,the fire front was controlled,gas channeling was slowed down,the fire flooding sweep coefficient was increased and the oil recovery was enhanced.For example,the initial gas injection rate is 10,000 m^(3)/d for Well I5-0151C2 and Well I51-156,and 10,500 m^(3)/d for Well I5-0158C.Supposing that the monthly increase of gas injection is 3,000 m^(3)/d,and horizontal wells produces at a fixed rate of 100 m^(3)/d,the fire front can advance evenly after parameter optimization,the sweep coefficient can increase by 8.74%,and the recovery can increase by 6.37%.