钻井液用聚合物弱凝胶的研制与性能研究

Preparation and properties of polymer weak gels for drilling fluids

以自制的六烯基单体TDED为交联单体、Na HCO_3和K2S2O8为引发剂,与丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和三乙基烯丙基氯化铵(TEAC)进行自由基水溶液聚合,合成了自交联聚合物弱凝胶PTAPT。FT-IR分析结果表明,其分子结构符合预期,并对其浓度-黏度关系、剪切稀释性和抗温性能进行了测定,实验结果表明,当PTAPT质量浓度为5 000 mg/L时,在复合盐水中的黏度为淡水中黏度的43.7%,在剪切速率为500 s^(-1)下剪切5 min后的保留率约为86.5%,经180℃老化72 h后,淡水和复合盐水中的黏度保留率分别为28.8%和31.7%。基浆性能测定表明,质量分数为2.0%的PTAPT可使老化前后的淡水与复合盐水基浆的黏度大幅上升,老化后淡水基浆的FLAPI为7.8 mL,复合盐水基浆的FLAPI为12.8 mL。

A self-crosslinking polymer weak gel PTAPT for drilling fluid is synthesized by free radical polymerization in aqueous solution with self-made 6-vinyl monomer TDED as crosslinking monomer,acrylamide（AM）,2-acrylamido-2-methylpropanesulfonic acid（AMPS） and triethylallyl ammonium chloride（TEAC） as other monomers,Na HCO3 and K2S2O8 as initiators.The results from FITR analysis show that the molecular structure of PTAPT is in line with expectation. The relationships between concentration and viscosity,shear dilution and temperature resistance are determined.The experimental results show that the viscosity in compound brine is 43. 7% of that in freshwater and the retention rate after shearing for 5 min at 500 s-1 shear rate is about 86. 5% when PTAPT concentration is 5 000 mg·L-1.After 72 h of aging at 180℃,the viscosity retention rates in freshwater and composite brine are 28. 8% and 31. 7%,respectively.The determination of base pulp shows that the viscosity of fresh water and composite brine base pulp before and after aging can be increased greatly by 2. 0% PTAPT.The FLAPIof fresh water and compound brine base pulps after aging is 7. 8 mL and 12. 8 mL,respectively.