水驱砂岩油藏优势渗流通道识别

Identification of preferential percolation path for water flooding sandstone reservoir

砂岩油藏经过长期注水开发后,通常形成水驱优势渗流通道,使得油井含水快速上升,注入水无效循环严重,油藏开发效果逐渐变差。基于储层物性变化规律和开发动态特征,分析了水驱砂岩油藏优势渗流通道的形成机理及优势通道形成原因。以南堡1-29断块为例,以注采井组为单元,以综合判别参数为主,计算注采井组间的水驱流场,利用Rdos栅状数值模拟和开发动态特征,划分出三类水驱优势渗流通道模式,结合示踪剂分析结果确定优势渗流通道的发育层位,并对主要渗流层进行了优势渗流通道的识别和描述,为制定油藏挖潜对策提供了重要参考依据。

After long-term water flooding development,the preferential percolation path of waterflooding has been usually formed in sandstone reservoirs.As a result,the water cut of oil wells rises rapidly,the ineffective recycling of injected water is serious,and the development effect of the oil reservoir becomes worse gradually.Based on the change rule of reservoir physical properties and development dynamic characteristics,it was analyzed the formation mechanism and reason for the preferential percolation path in the waterflooding sandstone reservoir.Taken the injection-production well group in Nanpu 1-29 fault-block as a unit,mainly based on comprehensive discriminant parameters,it was calculated the waterflooding flow field between injection and production wells.Based on the dynamic development characteristics and Rdos grid numerical simulation,three preferential percolation path modes of waterflooding were classified.The developmental horizon of the preferential percolation path was determined by the tracer analysis.In addition,the identification and description of the preferential percolation path of the main seepage layer can provide an important reference for the development of the oil reservoir exploration strategy.