梳型聚合物降滤失剂的合成及其在深井盐水钻井液中的应用

针对当前抗温抗盐聚合物降滤失剂在高浓度盐、二价盐存在下降滤失性能不够好的问题，以烯丙基聚氧乙烯醚400、丙烯酰胺和2-丙烯酰胺基-2-甲基丙磺酸为单体，采用水溶液聚合法合成得到无色透明黏稠的液体梳型聚合物降滤失剂DMP-1，其有效含量为30%。对其进行结构表征表明，大分子单体APEG400与单体AMPS、AM参与了反应，形成了梳型聚合物，且聚合反应进行完全。热重分析表明，该聚合物热分解温度为310℃。与常见抗温抗盐聚合物降滤失剂DSP-2、Driscal D、PAMS601进行的对比评价结果表明，该降滤失剂水溶液180℃高温老化后黏度降低率小于42.0%，抗温达200℃，抗盐达饱和，抗氯化钙达3%，与DSP-2等常见抗温抗盐聚合物降滤失剂相比，其抗饱和盐、抗钙离子的效果更加显著。在涪陵地区泰来201井和永兴1井三开盐膏层段及四开高温井段钻进中的应用表明，在高温、含盐、含Ca2+情况下降滤失效果显著，降低了盐水/钙处理钻井液的API滤失量和高温高压滤失量，保证了安全施工，在深井、饱和盐水/钙盐钻井液中具有良好的应用效果。 

Synthesis and Application of a Comb Polymer Filter Loss Reducer in Deep Well Saltwater Drilling Fluid

A comb polymer filter loss reducer, DMP-1, was synthesized through solution polymerization with allyl polyoxyethylene ether 400 (APEG400), acrylamide (AM), and 2-acrylamido-2-methyl propane sulfonic acid (AMPS). DMP-1 was developed in an effort to overcome the deficiencies of presently available high temperature salt-resistant filter loss reducers used in an environment with high salinity and divalent salts. The synthesized product was a viscous transparent liquid containing 30%DMP-1. Structure characterization of DMP-1 showed that APEG400, AMPS and AM all participated in the reaction to form the comb polymer and the polymerization was complete. Thermogravimetric analysis showed that DMP-1 decomposed at 320℃. Comparison of DMP-1 with the commonly used filter loss reducers such as DSP-2, Driscal D or PAMS601 showed that, after aging at 180℃, the percent reduction of the viscosity of DMP-1 was less than 42.0%, and the property of DMP-1 remained stable at 200℃. DMP-1 was resistant to salt contamination to saturation, and calcium contamination to 3%. These data indicate that DMP-1 works better in salt and calcium environment than the widely used high temperature salt-resistant filter loss reducers such as DSP-2. Application of DMP-1 in the 3rd interval (penetrating salt and gypsum formations) and the 4th interval (high temperature) of the well Tailai-201 and the well Yongxing-1 in Fuling area demonstrated that DMP-1 performed very well at high temperatures, high salinities and high calcium concentrations, effectively reducing the API filter loss of saltwater drilling fluids and calcium-treated drilling fluids, thereby ensuring the safety of drilling operation.