一种用作钻井液增黏剂的反相微乳液的性能研究

Properties of an Inverse Microemulsion Used as Viscosifier of Drilling Fluids

以丙烯酰胺(AM)、丙烯酸(AA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N,N-二甲基丙烯酰胺(DMAM)为单体,采用反相微乳液聚合合成了微乳液型钻井液增黏剂AM/AA/AMPS/DMAM。该增黏剂直接以微乳液的形式加入到钻井液体系中,当加量达到0.6%时(30℃),钻井液的表观黏度(AV)、塑性黏度(PV)、动切力(YP)和滤失量(FL)分别为26.5 mPa·s、16.0 mPa·s、10.5 Pa和14.2 mL。随热滚温度的升高,含1.0%增黏剂钻井液的AV、PV、YP均呈下降趋势,FL增大,但在150℃内的变化较小,耐温性较好。含2.0%增黏剂钻井液抗NaCl侵可达饱和,抗CaCl_2侵可达0.6%。该反相微乳液增黏剂与常规的钻井液增黏剂80A-51相比,其耐温抗盐性能有了较大幅度的提高。

A microemulsion viscosifler AM/AA/AMPS/DMAM was synthesized by inverse microemulsion polymerization with aerylamide （AM）, acrylic acid （AA）, 2-acrylamido-2-methylpropane sulfonic acid （AMPS） and N,N-dimethylacrylamide （DMAM） as monomers. The microemulsion could be added into the drilling fluids directly. The apparent viscosity （AV）, plastic viscosity（PV）, yield point（YP） and fluid loss（FL） of drilling fluids were 26.5 mPa. s, 16.0 mPa. s, 10.5 Pa and 14.2 mL accordingly when the addition amount of microemulsion was 0.6% at room temperature. The AV, PV and YP of drilling fluids showed downtrend and FL increased with increasing rolling temperature when the addition amount of microemulsion was 1.0%. But the variation was minor with the temperature less than 150℃, which showed good temperature tolerance. The NaC1 resisting concentration of the drilling fluids could reach saturation and CaC12 resisting concentration was 0.6% when 2.0% microemulsion added. Compared with the conventional viscosifler 80A-51, the temperature and salt tolerance of the synthesized polymer had been improved obviously.