【摘要】 针对煤层气开采过程中的储层损害问题，基于暂堵储层保护理论，以甲基丙烯酸甲酯、甲基丙烯酸酐及叔羧基甜菜碱为原料，研制了一种超支化聚合物暂堵剂MTA，并评价了其综合性能。红外图谱表明，3种单体已成功共聚，其热分解温度高达252℃；理化性能分析表明，MTA的分子量为6×10⁴，胺值为17.52，溶液为碱性，平均粒径在0.69～3.32μm;MTA减缓压力传递性能远优于常用封堵剂，抑制黏土膨胀性能与聚胺抑制剂相当，可使黏土层间距由1.92 nm降低至1.58 nm;MTA在压差作用下封堵岩石微孔隙，阻止水进入地层，并通过电荷作用吸附在岩石表面，形成层状结构阻止水分子向岩石渗透。结果表明，MTA与工作液其他处理剂具有良好的配伍性，可使工作液砂盘滤失量降低41.2%；在150℃下，MTA工作液具有优异的持效性和抗污染性能，可耐10%NaCl、5%CaCl₂或10%劣质土，其岩心渗透率恢复值可达87.3%，综合性能优异。MTA工作液现场应用，井径扩大率小于5%，具有优异的井壁稳定效果。更多还原

【Abstract】 To solve the problem of reservoir damage in coalbed methane development, a hyperbranched polymer temporary plugging agent MTA was developed based on the theory of reservoir protection by temporary plugging. The synthesis of MTA involves the use of raw materials such as methyl methacrylate, methyl acrylic anhydride and tert-carboxyl betaine etc. The performance of MTA was evaluated in laboratory experiment. IR spectroscopy shows that the three monomers have successfully copolymerized to form a new polymer. The thermal decomposition temperature of MTA is 252 ℃. Physical-chemical performance analysis results show that MTA has a molecular weight of 6 × 10⁴, an amine number of 17.52, a pH of greater than 7.0 and an average particle size of 0.69-3.32μm. Compared with the commonly used plugging agents, MTA has better ability in reducing pressure transmission. The capacity of MTA in inhibiting the swelling of clays is equivalent to the inhibitive capacity of polyamines; it reduces the interlayer space of a clay from 1.92 nm to 1.58 nm. Under the action of a differential pressure, MTA can plug the micropores in formation rocks to stop the invasion of water into the formation. Furthermore, MTA can be adsorbed onto the surfaces of a rock by the action of electric charges,thereby forming a layered structure to hinder the filtration of water molecules into the rock. Evaluation of MTA reveals that MTA has good compatibility with other additives in a working fluid, and reduces the amount of filtrate of the work fluid by 41.2%. At150 ℃, MTA working fluid has excellent performance sustainability and contamination resistance; it is resistant to contamination by10% NaCl, or 5% CaCl₂, or 10% clays of poor quality. Rock samples treated with the MTA fluid have their permeability recovered by 87.3%. In field operations, MTA showed excellent performance in maintaining borehole stability; the rate of hole washout was less than 5%.更多还原