缓速交联超高温合成聚合物压裂液稠化剂研究

针对水基压裂液体系中植物胶稠化剂及其衍生物存在残渣含量高、耐温差和易腐败变质等问题，基于水溶性高分子自由基合成理论，经室内高分子合成实验，研究了各种合成条件（引发剂浓度、聚合温度、反应pH值、聚合浓度、链转移剂含量、水解度）对稠化剂性能的影响规律。以丙烯酰胺(AM)、功能性单体（SP）、耐温单体（AMPS）作为共聚单体，采用控制变量法，通过合成条件优化，形成了一套性能优异的合成聚合物稠化剂基础配方，聚合浓度25%，单体配比（AMPS∶SP∶AM）30%∶25%∶45%，聚合温度20 ℃，引发剂浓度0.3%，聚合反应pH值为7，甲酸钠质量分数为0.2%，反应时间4 h。该稠化剂具备耐温、速溶、水不溶物含量低、增稠能力强，且与有机锆交联剂交联性能好，满足200 ℃地层的应用需要。 

Study on Fracturing Fluid Formulated with Ultra-High Temperature Retarded Crosslinking Polymers

Plant gum thickening agents and their derivatives used in water based fracturing fluids have some shortages such as high residue content, poor thermal stability and easy spoilage. To solve these problems, a new thickening agent was developed with acrylamide (AM), a functional monomer SP and 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) as the reaction monomers. In laboratory synthesis of this new thickening agent, based on the free radical polymerization of water-soluble polymer theory, the effects of the various synthesis conditions (such as concentration of the initiator, reaction temperature, pH of the reaction system, polymer concentration, content of the chain transfer agent and the degree of hydrolysis) on the performance of the final thickening agent were studied. Using the method of control variates, the reaction conditions are as follows: Polymer concentration = 25%, ratio of monomers (AMPS∶SP∶AM) = 30%∶25%∶45%, reaction temperature = 20 ℃, concentration of initiator = 0.3%, pH = 7, mass fraction of sodium formate = 0.2%, reaction time = 4 h. The thickening agent synthesized has good high temperature resistance, low water insoluble and high thickening capacity. It is instantly soluble and can be easily crosslinked with the organozirconium crosslinking agent. This thickening agent can be used in formation temperatures as high as 200 ℃.