重复压裂新缝起裂位置与油井产量的关系

Relationship between production and initiation location of new fractures in re-fractured well

针对重复压裂不同起裂位置对油井产量的影响问题,采用油藏流动模型和水力裂缝流动模型共同描述系统的流动。提出了针对重复压裂裂缝系统的分析单元,并在采用有限差分法求解系统方程并编制模拟软件的基础上,研究了新缝形成对井网压力分布的影响,并得到了新缝起裂位置对油井产量的影响。研究发现,新缝在不同位置起裂对于井网的压力分布,尤其是裂缝系统附近压力的分布影响很大;新裂缝起裂位置在离开井底10m范围以内,油井累积产量下降较慢,之后下降幅度增加;建议通过工程手段将新缝的起裂位置控制在10m以内。

To investigate the effect of initiation location of new fractures on well production, a reservoir model and a hydraulic fracture model are combined to model the fluid flow after re-fracturing. Based on the analytical unit in the fracture system caused by re-fracturing, and the solution of system equations obtained from finite difference method, this paper investigates the impact of new fractures on pressure distribution within a well network, and that of initiation locations of new fractures on well production. The study shows that different initiation locations of new fractures in re-fracturing have significant impact on pressure distribution, in particular, around a fracture system. Also, the accumulative well production decreases slowly within 10 m range of new fracture initiates at well bottom, while a decreasing rate will be increased when a 10 m range is exceeded. It suggests that the initiation locations of new fractures in re-fracturing be controlled within 10 m range from a well.