油基钻井液用聚合物降滤失剂的合成与性能评价

Synthesis and performance evaluation of polymer fluid loss additive for oil-based drilling fluid

摘要:

针对国内现有油基钻井液用聚合物降滤失剂种类较少的问题，文章选用丙烯酰胺（AM）、甲基丙烯酸十八酯（SMA）为反应单体，偶氮二异丁腈（AIBN）为引发剂，二乙烯基苯（DVB）为交联剂采用分散聚合法合成油基钻井液用降滤失剂。在实验过程中采用单因素分析法对各反应条件进行了优化，通过对钻井液体系API滤失量的测定最终确定合成最佳条件为单体配比1:3、单体浓度5%、引发剂浓度0.7%、交联剂浓度2%、V（甲醇）：V（水）=7:3、分散剂浓度为4%、反应温度70℃、反应时间6h。利用红外光谱实验对合成产物进行分析，其结构与预期一致。利用热差分析实验得到DSC曲线，分析可知聚合物的玻璃化转变温度为111℃。通过一系列钻井液评价实验可知该降滤失剂加量为3%时API滤失量最低为1.6mL，HTHP滤失量为7.2mL，高温老化实验结果表明该降滤失剂最低可抗温160℃，与沥青类降滤失剂相比其对钻井液流变性影响明显降低，且相同加量下形成的泥饼质量优于沥青类。

Abstract:

In view of the current domestic problems of fewer types of polymer fluid loss additives for oil-based drilling fluids. Choosing Acrylamide（AM）、Stearyl methylacrylate（SMA）as reaction monomers, 2-methylpropionitrile（AIBN）as initiator, Divinylbenzene（DVB）as crosslinker. The oil based fluid loss additive was synthesized by dispersion copolymerization. Single factor method is used to determine the best synthetic condition of fluid loss additive. Through measure the APT filtrate losses determine the monomer ratio of AM:SMA=1:3, the monomer concentration is 5%, the crosslinker concentration is 2%, the initiator concentration is 0.7%, V（methanol）:V（H2O）=7:3, the stabilizer concentration is 4%, polymerization temperature is 70℃, polymerization time is 6h. Fourier transform infrared spectroscopy shows that the structure of the product is consistent with the design, the glass transition temperature is 110℃ through DSC measure. When the dosage of fluid loss additive is 3%, the API fluid loss is 1.6mL, HTHP fluid loss is 7.2mL,The high-temperature aging test show that the fluid loss additive has the temperature resistance of 160℃. the result show that the synthesized product has better performance as oil based fluid loss additive than asphalt and have no effect on drilling fluids’ rheology, and the quality of mud cake is better than the asphalt under the same dosage.