摘要
用压汞法测定了有代表性的榆树林油田储层岩心(Ka≈1×10-3μm2)的微观孔隙结构,构建了喉道半径、孔隙半径、孔喉半径比分布曲线。由所得孔隙结构数据,取喉道半径约1.275μm、Ka约1×10-3μm2的8个岩心进行模拟注水实验。模拟注水为仅含模拟悬浮颗粒(石英砂)的蒸馏水,石英砂的粒径(平均值和分布范围)用滤膜过滤法控制。岩心饱和模拟地层水后注入含一定浓度、一定粒径石英砂的蒸馏水,测岩心水测渗透率损失率。认为渗透率损失率超过30%时地层受到的伤害不可忽视。当石英砂半径上限为0.365μm,石英浓度增加至0.5mg/L时渗透率损失率增大至30%;当石英砂浓度为0.5mg/L,石英砂平均半径增加至0.5μm时渗透率损失率增大至30%。认为Ka为1×10-3μm2的榆树林油田注入水中悬浮颗粒浓度应小于0.5mg/L,粒径应小于1μm。讨论了颗粒堵塞多孔介质的机理。
The microscopic porous structure of a representative Yushulin oil reservoir core of air permeability Ka≈1×10^-3μm^2was determined by using mercury instrusion method and the distribution of throad radius,pore radius,and pore-to-throat radius ratio was constructed. On the basis of porous structural data obtained,8 reservoir cores of throat radius ~1.275 μm and Ka^1×10^-3μm^2were selected for simulation water flooding experiments. The simulation flooding water was distilled water containing quartz sand（QS） as simulation suspended solids and the average particle size and the size distribution of QS were controlled by using membrane filtration method. The experimental cores were saturated by simulation formation water and injected by distilled water with QS of definit concentration and particle size added and the water permeability reduction（WPR） of the cores was determined. A WPR reaching 30% was considered to be an unneglectable formation damage. The WPR rose to 30% when the QS concentration increased to 0.5 mg/L at QS radius ≤0.365 μm or when the QS radius increased to 0.5 μm at QS concentration 0.5 mg/L. It was suggested that the suspended solids concentration should be 〈0.5 mg/L and their particle size —〈1 μm in the flooding water for Yushulin oil reservoir of Ka 1×10^-3μm^2 The mechanisms involved in plugging porous media by solid particles were discussed.
出处
《油田化学》
CAS
CSCD
北大核心
2010年第1期43-46,共4页
Oilfield Chemistry
关键词
低渗透储油层
孔喉结构
注入水
悬浮固体
粒径
粒径分布
堵塞机理
榆树林油田
low permeability oil reservoir
pore-throat structure
flooding water
suspended solids
particle size
size distribution
plugging mechanisms
Yushulin oil field
