新型聚羧酸减阻剂的研究与应用

针对伊拉克地区夏季环境温度高导致现场配制的水泥浆触变性强，可泵性差，现有减阻剂难以使水泥浆保持良好分散能力，严重影响固井施工安全的问题。以聚乙二醇二丙烯酸酯、甲基丙烯酸、2-丙烯酰胺-2-甲基丙磺酸和芳香磺酸类单体等为原料，合成了一种新型聚羧酸油井水泥减阻剂BH-D301L。采用正交实验得到了最佳合成原料物质的量比为1∶4∶1∶1，反应温度为80℃，反应时间为2 h，引发剂加量为0.4%。通过红外光谱分析和渗透凝胶色谱表征证明了合成产物为共聚物，参考API RP 10B标准评价了加入减阻剂的不同水泥浆体系的综合性能。实验结果表明，加量分别为0.5%和1.0%的减阻剂对常规密度的自来水和饱和盐水配浆水泥浆体系的流变性能有明显改善，体系抗压强度和稠化时间符合行业标准要求。在模拟环境温度45～65℃下，加有1.0%减阻剂的高密度含盐水泥浆的流性指数大于0.7，稠度系数小于0.58Pa · sn，体系触变性增强现象减弱，静切力差小于3 Pa，24 h抗压强度超过14 MPa，水泥浆体系稠化、沉降稳定性均能满足固井施工要求，并在现场得到了很好的应用。 

Study and Application of a New Poly Carboxylic Acids Drag Reducer

Cement slurry mixed in Iraq has strong thixotropy and poor pumpability in summer, and the drag reducers presently in use are unable to render the cement slurries good dispersibility. These problems have seriously affected the safe performance of well cementing. To address these problems, a new poly carboxylic acids drag reducer, BH-D301L, has been developed with monomers such as polyethylene glycol diacrylate, methacrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and aromatic sulphonic acid etc. Using orthogonal experiment, the optimum conditions for the reaction was determined to be as follows:molar ratio of the monomers of 1:4:1:1, reaction temperature of 80℃, reaction time of 2 h, and initiator concentration of 0.4%. The reaction product was characterized by IR spectroscopy and gel permeation chromatography, and was tested for its general performance in different cement slurries in accordance with API RP 10B. Experimental results showed that by adding 0.5% and 1.0% of the drag reducer into a cement slurry formulated with fresh water and a cement slurry formulated with saturated saltwater, the rheology of the cement slurries were obviously improved. The compressive strengths and thickening time of the cement slurries satisfied the requirements of industrial standards. At simulated temperatures of 45-65℃, a high-density salt-containing cement slurry treated with 1.0% drag reducer had flow index of greater than 0.7 and consistency factor of less than 0.58 Pa·sn. The thixotropy of the cement slurry treated with the new drag reducer had thixotropy increased less obviously. Gel strength of the cement slurry was less than 3 Pa and 24 h compressive strength exceeded 14 MPa. The cement slurry treated with the drag reducer had thickening property and settling stability all satisfied the needs of well cementing job, and was successfully used in field operations.