基于储层时变的水驱优势通道治理对策

Control Strategies for Dominant Channels of Water Flooding Based on Time-varying Characteristics of Reservoirs

海上某水驱油藏存在明显的水驱优势通道。水驱优势通道的形成,宏观上是流固耦合作用的结果,微观上主要表现为岩石骨架结构、孔喉半径及连通性等特征参数的变化。通过非线性拟合建立渗透率及相渗曲线端点与水驱通量的时变关系,并耦合到模型中,建立物性随时间变化的油藏物性时变模型。在此基础上,开展井间水驱优势通道治理对策研究,提出调剖段塞封堵优势通道、组合段塞深度调剖封堵多级优势通道、组合段塞深度调剖后有效接替驱替三种治理方式,并应用于矿场实践。结果表明,针对油通比低于0.001m-1的水驱优势通道区域,三项对策均可达到一定的治理效果。以调剖治理优势通道,建议首要封堵中部优势通道,并在保证经济性的条件下适当扩大封堵范围。针对不同级别优势通道的组合段塞深度调剖治理方式,相比单段塞调剖效果更优。治理优势通道后有效的接替驱替方式是发挥封窜潜力的关键,采用组合段塞深度调剖后转调驱,可达到相对最优的优势通道治理效果。

There are obvious dominant channels of water flooding in a certain offshore water flooding reservoir.The formation of dominant channels of water flooding is the result of fluid-solid coupling macroscopically and mainly behaves as changes in characteristic parameters such as rock skeleton structure,pore throat radius,and connectivity microscopically.The time-varying relationship between the permeability,the endpoints of relative permeability curves,and the water flooding flux is established through nonlinear fitting.It is coupled to the model,and a time-varying model of reservoir physical properties that changes with time is established.On this basis,we researched control strategies for the inter-well dominant channels of water flooding and pro-posed three ways:slugs during profile control block the dominant channels,depth profile control with combined slugs blocks multi-level dominant channels and effective replacement after depth profile control with combined slugs.They are applied to field practice.The results show that all three countermeasures can achieve certain effects in dominant channel areas of water flooding where the oil-to-flux ratio is lower than 0.001m-1.To control the dominant channels through profile control,it is recommended to first block the dominant channels in the middle part,and appropriately expand the blocking range while ensuring economy.The method of depth profile control with the combined slug for the dominant channels in different levels has a better effect than the profile control with a single slug.Effective successive displacement after controlling the dominant channels is the key to having the potential to block channels.Displacement after deep profile control with combined slug can achieve relatively optimal management results for the dominant channels.