新型抗高温抗盐钻井液增黏剂PADA的制备与性能

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N, N-二甲基丙烯酰胺(DMAM)和丙烯腈(AN)为共聚单体，失水山梨醇单油酸酯(Span80)和聚氧乙烯失水山梨醇单油酸酯(Tween80)为复配乳化剂，白油为油相，NaHSO₃ 和(NH₄)₂S₂O₈为氧化还原引发剂，通过正交试验，反相微乳液聚合法制备了增黏剂AMPS-DMAM-AN三元共聚物(PADA)。利用傅里叶变换红外光谱(FT-IR)和热重分析(TGA)研究了PADA的结构和热稳定性，评价了PADA在钻井液中的增黏、降滤失性能。结果表明，增黏剂PADA具有良好的热稳定性，能有效提高淡水钻井液和饱和盐水钻井液的黏度，并降低滤失量，高温老化前后各参数变化不大，抗高温抗盐性能优异。因此，该增黏剂有望在高温地层、盐膏地层的深井钻探中得到应用。

Preparation and Properties of Heat- and Salt- Tolerant Viscosity Improver PADA in Water-Based Drilling FluidDilling Fluid

A novel viscosity improver AMPS-DMAM-AN (PADA) was prepared by using 2-acrylamide-2-methylpropanesulfonic acid (AMPS), N,N-dimethylacrylamide(DMAM) and acrylonitrile (AN) as comonomers, Span80 and Tween80 as the emulsifiers, while oil as the oil phase, NaHSO₃ and (NH₄)₂S₂O₈ as the initiator via inverse microemulsion polymerization, and was characterized by FT-IR and TGA. The optimum reaction conditions of polymerization were obtained from the orthogonal experiments. The rheological property and filtration loss property of drilling fluids were evaluated before and after adding PADA in several water-based drilling fluids at different aged temperatures. Results showed that PADA possessed excellent thermal stability, and the water based drilling fluids containing PADA exhibited excellent viscosity-improving, filtrate loss-reducing, heat-resistance and salt-tolerance properties. Hence, PADA seemed to be of great promise as viscosifying and filtration-reducing additive under the salty and high temperature environment.