耐温抗盐改性淀粉钻井液降滤失剂的合成及性能研究

Synthesis and Performance of Modified Starch with Heat Risistance and Salt Tolerance

以淀粉和一种自制的同时带有磺酸基和季铵阳离子的烯烃单体为原料合成了一种耐温性能可达180℃的改性淀粉YS,并考察了其降滤失性能、抗盐及抗钙性能、耐温性能及抑制性能。研究结果表明:YS在淡水基浆、海水基浆、饱和盐水基浆、复合盐水基浆及含钙盐水基浆中均具有较好的降滤失效果;添加1.5%数2.5%的YS后,钻井液的滤失量均可显著降低并控制在10 m L之内;抗盐及抗钙性能均可达到饱和,且随含盐量的增加,降滤失效果和提黏切能力反而增强;与淡水基浆相比,加入2.0%YS后的基浆的表观黏度上升率可由300%降至73.3%;与清水相比,2.0%YS水溶液可将黏土块的线性膨胀率由51.5%降至10.2%,YS表现出较好的抑制黏土水化分散、膨胀的性能。

a modified starch YS of heat tolerance up to 180℃ was synthesized by using starch and a novel vinyl monomer containing sulfonic groups and quaternary aminonium cation,as raw materials,and the performance of fluid loss,salt and calcium resistance,heat tolerance and inhibition were also evaluated. The experimental results showed that YS had better filtration reduction properties,whatever in fresh water,seawater,saturated brine,complex brine and calcium chloride brine base slurry. The filtrate loss of the drilling fluids could be controlled within 10 m L after adding 1.5%-2.5% YS. The salt tolerance and anti-calcium performance were all to saturation,and the effect of filtration reduction and ability to improve viscosity and shear of the YS was enhanced with the increase of salt content. After adding 2.0% YS into the fresh water base slurry,the rising rate of apparent viscosity could decrease from 300% to 73.3%,while compared with the water,the 2.0% YS solution could make the linear expansion rate reduce from 51.5% to 10.2%,which indicated that YS had better performance in inhibiting hydration and expansion of shale.