基于双径向流模型的产能计算及射孔优化技术

Productivity calculation method of perforated vertical well based on dual radial flow model and perforation optimization

应用等值渗流阻力法和双径向流模型,分射穿污染带与未射穿污染带两种情况,推导出各向同性油藏射孔直井的产能公式,考虑了孔深、孔密、孔径、相位、压实带、污染带等因素对产能的影响。在此基础上,根据各向异性油藏渗流理论,得到各向异性油藏射孔直井产能公式。利用推导的公式对射孔直井产能进行参数敏感性分析,结果表明:射孔直井产能随着孔深、孔径、孔密、相位、垂向渗透率等参数的增大而增大,随着压实带厚度和压实程度的增大而减小;各参数在射穿污染带时的敏感性小于未射穿污染带时的敏感性;孔深、孔密、压实程度、垂向渗透率对产能的影响比较大。工程设计时,应优先考虑孔深、孔密,并避免压实损害程度过高,矿场应用时,结合储层物性特征和作业实际需求,选用合适的射孔器材,形成一套具有针对性的射孔优化技术。

Based on the dual radial flow model, this paper used equivalent flowing resistance method to presents productivity formulas of perforated vertical well in isotropic reservoir for two cases, damaged-zone penetrated and partially penetrated.The effects of perforation length, shot density, perforation diameter, phasing, crushed zone and damaged zone on the perforation performance are considered.On this basis, the productivity formulas of perforated vertical well in anisotropic reservoir are obtained using the principle of fluid mechanics in anisotropic reservoir.Based on the derived formulas, sensitivity analysis on the performance of perforated vertical well is conducted with the results showing that the productivity of perforated well increases with perforation length, shot density, perforation diameter, phasing and vertical permeability while decreases with crushed zone thickness and compaction damage degree.Parameters with damages-zone penetrated are less sensitive than partially penetrated.The perforation length, shot density, compaction damage degree and vertical permeability have great influence on reservoir productivity.Priority should be given to the perforation length, shot density, and avoid excessive high compaction damage degree while engineering design.In real practice,consider formation properties and operation needs,choosing the proper perforation tools and optimize to be a specific technology.