雾化/泡沫钻井用两性聚合物防塌剂WPZY-1的研制

以阳离子单体(YD-1)、丙烯酸(AA)、丙烯酰胺和烷基取代丙烯酰胺为原料,过硫酸铵和亚硫酸氢钠(质量比1∶1)为引发剂,合成了一种雾化/泡沫钻井用两性聚合物防塌剂WPZY-1,考察了该剂抑制防塌性能。以单体总量计,引发剂、AA和YD-1最佳加量分别为0.5%~1.0%、3%~5%和5%~10%。性能评价结果表明,WPZY-1吸附能力强、抑制防塌性能好。饱和吸附量达100.98 mg/g。0.5%WPZY-1溶液48 h二次页岩相对回收率为99.3%,岩心24 h膨胀量为1.58 mm,人造岩心浸泡10 d后形状规则完整,无明显裂纹及剥落掉块现象。WPZY-1与雾化/泡沫钻井流体处理剂的配伍性良好,可有效提高抑制防塌性能,延长井壁稳定时间,满足高出水地层的应用需求。

Research and Development of Amphoteric Polymer Anti-Sloughing Agent WPZY-1 for Mist/Foam Drilling

An amphoteric polymer anti-sloughing agent named WPZY-1 used in air-mist/foam drilling was synthesized using cationic monomer (YD-1), acrylic acid, acrylamide and alkyl substituted acrylamide as raw material, and ammonium persulfate and sodium bisulfate in mass ratio 1:1 as initiator. Its inhibition and anti-sloughing performance was investigated. The optimum dosage of initiator, AA and YD-1 was 0.5%~1.0%, 3%~5% and 5%~10% of total monomers. The performance evaluation results showed that WPZY-1 had strong adsorption capacity and good anti-sloughing property, with a saturated adsorption amount of 100.98 mg/g. The secondary shale recovery rate in 0.5% WPZY-1 solution after 48 hrs was 99.3%. The expansion amount of core after 24 hrs was 1.58 mm. Moreover, the artificial core soaking in WPZY-1 solution could keep regular integrity shape after 10 d with no cracks and peeling phenomenon. WPZY-1 had good compatibility with air-mist/foam drilling agents and its application could effectively improve the inhibition and anti-sloughing performance, and extend wellbore stability time, which met the requirements in high water exit formation.