Three-layer core/shell latex particles with various shell crosslinking level and shell thickness were prepared by multistep emulsion polymerization, and the hollow latex particles with different morphologies were then...Three-layer core/shell latex particles with various shell crosslinking level and shell thickness were prepared by multistep emulsion polymerization, and the hollow latex particles with different morphologies were then obtained after alkali post-treatment. Influences of divinyl benzene （DVB） content and the core/shell mass ratio on emulsion polymerization and particle morphology were investigated. Results showed that with the increase of DVB content, the percentage of total amount of --COOH on the particle surface and free in aqueous phase （PSFa） decreased, and the morphology of the post-treated particles underwent evolution from cracked, intact hollow to deficient swelling structure. Decreasing the core/shell mass ratio could not only make more carboxyl groups encapsulated by the shell, but also increase the shell resistance to the swelling of the core. The uniform hollow latex particles with intact morphology were obtained when the DVB content was 3.54 wt% and the core/shell mass ratio was 1/6.展开更多
页岩油气地层微孔隙发育,滤液侵入地层易引起泥岩水化膨胀,导致井壁失稳,传统封堵剂难以有效封堵页岩微孔隙。以纳米SiO2为核,甲基丙烯酸甲酯和丙烯酸甲酯作为“壳层”,引入多官能团单体增强“壳层”材料力学性能与抗温性能,采用乳液聚...页岩油气地层微孔隙发育,滤液侵入地层易引起泥岩水化膨胀,导致井壁失稳,传统封堵剂难以有效封堵页岩微孔隙。以纳米SiO2为核,甲基丙烯酸甲酯和丙烯酸甲酯作为“壳层”,引入多官能团单体增强“壳层”材料力学性能与抗温性能,采用乳液聚合方法制备了核壳结构纳米封堵剂SMNR-2,利用红外光谱、粒度分析、微观电镜以及热重分析等实验对SMNR-2开展了表征及性能评价,结果表明,SMNR-2粒度为100~800 nm,D50为409.3 nm,在350℃范围内表现出较好的热稳定性。SMNR-2与水基钻井液配伍性较好,160℃高温高压失水可降至6.2 m L左右,页岩压力传递实验表明,SMNR-2可进入页岩微孔隙进行封堵,封堵降滤失效果优于国外同类产品,该纳米封堵剂在威荣页岩长水平井应用效果良好。展开更多
文摘Three-layer core/shell latex particles with various shell crosslinking level and shell thickness were prepared by multistep emulsion polymerization, and the hollow latex particles with different morphologies were then obtained after alkali post-treatment. Influences of divinyl benzene （DVB） content and the core/shell mass ratio on emulsion polymerization and particle morphology were investigated. Results showed that with the increase of DVB content, the percentage of total amount of --COOH on the particle surface and free in aqueous phase （PSFa） decreased, and the morphology of the post-treated particles underwent evolution from cracked, intact hollow to deficient swelling structure. Decreasing the core/shell mass ratio could not only make more carboxyl groups encapsulated by the shell, but also increase the shell resistance to the swelling of the core. The uniform hollow latex particles with intact morphology were obtained when the DVB content was 3.54 wt% and the core/shell mass ratio was 1/6.
文摘页岩油气地层微孔隙发育,滤液侵入地层易引起泥岩水化膨胀,导致井壁失稳,传统封堵剂难以有效封堵页岩微孔隙。以纳米SiO2为核,甲基丙烯酸甲酯和丙烯酸甲酯作为“壳层”,引入多官能团单体增强“壳层”材料力学性能与抗温性能,采用乳液聚合方法制备了核壳结构纳米封堵剂SMNR-2,利用红外光谱、粒度分析、微观电镜以及热重分析等实验对SMNR-2开展了表征及性能评价,结果表明,SMNR-2粒度为100~800 nm,D50为409.3 nm,在350℃范围内表现出较好的热稳定性。SMNR-2与水基钻井液配伍性较好,160℃高温高压失水可降至6.2 m L左右,页岩压力传递实验表明,SMNR-2可进入页岩微孔隙进行封堵,封堵降滤失效果优于国外同类产品,该纳米封堵剂在威荣页岩长水平井应用效果良好。
