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由分子量 3× 10 6～ 5× 10 6、水解度 2 5 %的聚丙烯酰胺 (5～ 6 g/L)、重铬酸钠的氧化还原体系、延缓剂 (10 0～6 0 0mg/L)组成的聚合物强凝胶堵剂 ,可用 pH值 6 .5～ 8、矿化度 <1× 10 5mg/L的水配制 ,温度 2 0～ 75℃范围内成胶时间可在 0 .5～ 8天范围内调节。报道了典型配方实验堵剂液的性能研究结果 :在 5 0℃时 ,在人造砂岩岩心中的成胶时间为 44小时 (由突破压力曲线测得 ) ,岩心封堵率 >99.9%,经注水 5 0PV冲刷后仍不低于 99.8%,突破压力梯度在高渗透率 (87.9μm2 )岩心中不低于 30MPA/m ,在低渗透率 (9.0 μm2 )岩心中较低 ,为 2 3MPA/m ,显示了一定的选择性。在 3支串联高渗透率岩心和 3支串联低渗透率岩心并联而成的非均质模型上 ,在水驱饱和油之后(合层采收率 18.8%) ,依次用实验堵剂封堵第一、第二、第三高渗透岩心后水驱 ,合层采收率分别达到 41.8%,6 1.5 %和 74.8%。由各个岩心和岩心组的采收率得出结论 :封堵深度越大 ,采收率提高幅度越大。讨论了有关的驱油机理。
It is composed of polyacrylamide (5 ~ 6 g / L) with molecular weight 3 × 10 6 ~ 5 × 10 6, degree of hydrolysis 25%, redox system of sodium dichromate, retarding agent (10 0 ~ 600 mg / L ) Composed of a strong gel plugging agent can be pH 6 .5 ~ 8, the degree of mineralization <1 × 105mg / L of water preparation, the temperature range of 20 ~ 75 ℃ gel time can be 0.5 ~ 8 days to adjust the range. The results of the research on the performance of plugging solution of typical formula were reported. The gelling time in artificial sandstone core was 44 hours (measured by the breakthrough pressure curve) at 99 ℃ and the plugging rate of core was> 99.9% The breakthrough pressure gradient is not less than 99.8% after 50PV erosion. The breakthrough pressure gradient is not lower than 30MPA / m in cores with high permeability (87.9μm2) and 23MPA / m in cores with low permeability (9.0μm2) Shows a certain degree of selectivity. In a heterogeneous model with three parallel high permeability cores and three parallel low permeability cores connected in parallel, after the water flooding saturated oil (combined recovery of 18.8%), followed by plugging with experimental blocking agent After the second and third high-permeability cores, the waterflooding and co-layer recovery rates reached 41.8%, 61.5% and 74.8% respectively. It is concluded from the recovery rates of each core and core group that the greater the plugging depth, the greater the increase in recovery. Discussed the relevant oil displacement mechanism.