抗高温耐盐钙五元共聚物降滤失剂的合成与性能

针对深部地层钻井过程中遇到的高温、高矿化度等问题，以AM、AMPS、DMDAAC、DMAM、SAS为聚合单体，采用氧化-还原引发体系进行水溶液共聚，合成了一种五元共聚物降滤失剂。通过优化实验确定最佳合成条件，采用红外光谱和热重分析进行表征，并评价其在钻井液基浆中的性能。实验结果表明，合成的五元共聚物抗温达180℃、抗盐至饱和、抗钙达1.25%；五元共聚物加量为2%时，淡水、饱和盐水及含1.25% CaCl₂的基浆经180℃老化16 h后的滤失量分别为6.4、15.6和7.2 mL，均为加2% Driscal的不同基浆滤失量的50%左右。 

Synthesis and Properties of a High Temperature Calcium and Salt Resistant Quinary Copolymer Filter Loss Reducer

A quinary copolymer filter loss reducer for use in high temperature and high salinity environment has been developed with AM, AMPS, DMDAAC, DMAM and SAS as monomers through water solution copolymerization using redox initiation system. The optimum synthesis conditions were determined laboratory experiment. The synthesized filter loss reducer was characterized with IR spectrometry and thermogravimetry, and was evaluated for its properties in water base drilling fluid. The experimental results show that the synthesized quinary copolymer is resistant to high temperature to 180℃, to salt contamination to saturation, and to calcium contamination to 1.25%. Fresh water base mud, saturated saltwater base mud and base mud containing 1.25% treated with 2% synthesized quinary copolymer had filtration rate of 6.4 mL, 15.6 mL and 7.2 mL, respectively after being aged for 16 hours at 180℃. Compared with similar additive Driscal, the synthesized quinary copolymer is more effective in resisting high temperature, salt contamination and calcium contamination. The filtration rates as mentioned above are only about 50% of the same base muds treated with 2%Driscal, respectively.