改性淀粉接枝共聚堵剂成胶性能研究

为研究非均质性油藏条件下堵剂的成胶性能,室内使用自主研制的纵向非均质二维长岩心模型和常规的单管与并联填砂管对改性淀粉接枝共聚堵剂进行了研究。结果表明:堵剂配方为5%改性淀粉+5%丙烯酰胺+0.05%交联剂+0.1%引发剂时的注入性良好,对高渗、中渗和低渗填砂管的封堵能力良好,封堵率分别为99.2%、97.1%和91.0%;选择性较好,优先进入高渗透层进行封堵,并随着渗透率级差的增加,注入选择性增强;对长岩心模型水驱形成的大孔道进行了有效的封堵,使得中低渗潜力储层得到充分的动用,高渗、中渗和低渗储层的水驱采收率分别增加2.2%、3.3%和5.6%,最终采收率提高11.1%;耐冲刷能力强。该堵剂成胶性能良好,适用于非均质性稠油油藏。

Gel Performance of Modified Starch Graft Copolymer Shutoff Agent

In order to obtain the gel performance on the condition of reservoir with heterogeneity, modified starch graft copolymer plugging agent was studied using conventional single sand pipe, parallel sand pipes and independently developed two-dimensional vertical heterogeneous long-core model. The experiment results showed that the plugging agent consisted of 5% modified starch, 5% acryl amide, 0.05% cross-linking agent and 0.1% initiator had good injectivity. The plugging rate of plugging agent to high permeability, media permeability and low permeability sand pipes was 99.2%, 97.1% and 91.0% respectively, showing good plugging ability. The plugging agent had good injection selectivity which preferred to plug high permeability layer. With the increase of permeability contrast, the injection selectivity improved. The plugging agent effectively plugged large channel of heterogeneous long-core model caused by water flooding. The medium and low permeability reservoirs had been fully utilized. The water flooding recovery efficiency of high permeability, medium permeability and low permeability reservoir increased by 2.2%, 3.3% and 5.6%, respectively, and the ultimate recovery rate increased by 11.1%. Finally, it had strong washing resistance ability. The plugging agent had good gel performance, which could be applied to heterogeneous heavy oil reservoir.