聚驱后SDCM-1/聚合物二元复合体系提高采收率研究

SDCM-1/HPAM Surfactant/Polymer Combinational Flooding Fluid for Further Enhanced Oil Recovery after Polymer Flood Finished

表面活性剂SDCM-1为天然羧酸盐的氧乙烯基化产物。用矿化度4.5 g/L的矿化水配制的SDCM-1溶液,与孤岛河滩区原油之间的最低界面张力(70℃),在SDCM-1浓度大于1.0 g/L时达到10-4mN/m数量级。2.0 g/LSDCM-1+1.6 g/L HPAM溶液黏度超过原油黏度(70℃),与原油间的界面张力(70℃)在56 min时可降至稳定的最低值3.2×10-3mN/m,此即为所选二元复合驱配方。在岩心驱油实验中,水驱后、注聚后(1.6 mg/L,0.3 PV)、注二元复合体系(0.3 PV)并水驱后采收率分别为42.31%,5.21%,18.07%。在平板夹砂模型上采用相同工艺驱油,按所摄图像驱替面积测算各驱替液波及体积,注入水为51%,聚合物为48%,0.1、0.2、0.3 PV二元复合体系分别为54%、60%、64%,后续注入水为68%;用软件计算的水驱、注聚后、二元复合驱并水驱采收率,分别为44%,8%,16%。该体系是可用于聚驱后油藏的高效表聚二元复合驱油体系。

Surfaetant SDCM-1 is an ethoxylated product of natural carboxylate SDC. The minimum dynamic interracial tension （IFT） at 70℃ between SDCM-1 solution in formation water of TDS = 4.5 g/L and crude oil of Hetan, Gudao, decreases down below 1×10^-3 mN/m at SDCM-1 concentration 〉1.0 g/L. The visoasity at 70℃ of 2.0 g/L SDCM-1 ＋ 1.6 g/L HPAM solution is higher than that of the crude oil and the IFT at 70℃ between the solution and the crude oil decreases down to a steady minimum of 3.2×10^-3 InN/m in 56 rain. It is the SP combinational flooding fluid chosen. In a core flooding experiment, oil recovery of 42. 13 %, 5.21%, and 18.07 % is observed after water flood finished, polymer slug of concentration 1.6 g/L and size 0.3 PV injected, and SP combinational slug of size 0.3 PV injected and successive water flood finished. A core flooding experiment is conducted on a planar sand packed model with the same injection procedures, the percentage volume sweeped by every flooding fluid is determined by measuring the area flooded on recorded photos, being of 51% for flooding water, 48% for 0.3 PV polymer, 54%, 60%, and 64% for 0.1, 0.2, and 0.3 PV SP combinational solution, respectively, and 68% for terminal flooding water and the oil recovery calculated with the help of a software program is of 44% for water flood, 8% for polymer flood just after polymer slug injected, and 16% for SP combinational flood with successive water flood finished. The flooding fluid under study is a high effective SP flooding system suitable for polymer flooded oil reservoirs.