关键词: 耐高温,    ,  水解度,    ,  , 老化时间,    ,  , 第一法向应力差,   ,  , 驱油效果

Abstract: According to the characteristics of physical reservoir properties of the Shuanghe Ⅶ13layer series, such as high formation temperature(96.5 ℃) and low permeability, heatresistant polymer with molecular weight of 2 200×104 which was produced by Henan oilfield was selected to study characterization of polymer and oil displacement efficiency. The degree of hydrolysis，solution viscosity and first normal stress difference were measured at 95 ℃. And core flooding experiments were conducted to evaluate whether heatresistant polymer had good application. The results showed that the hydrolytic degree of heatresistant polymer was increased faster at the early aging, while the growth rate was slowed when the hydrolytic degree reached a certain level and kept the longterm stability in 60 days. The solution viscosity experienced three process in 90 days: first decreased then increased, finally decreased slowly. The viscosity retention ratio was maintained above 80% and the higher the concentration of solution, the better retention ratio. The first normal stress difference also experienced the same process as solution viscosity and retention ratio was maintained above 49%.It illustrated this polymer had good elastic retention ability. The oil displacement experiment showed that the oil flooding efficency was above 24% when injection concentration was 2 000 mg/L and the slug size was 0.5 PV.

Key words: Heatresistant,    ,  Hydrolytic degree,    ,  Aging time,    ,  First normal stress difference,    , Oil displacement efficiency