抗高温无机/有机复合纳米降滤失剂室内研究

Research on inorganic/organic composite-nano fluid loss additive resistant to high temperature

针对现有合成聚合物或天然改性高分子降滤失剂易高温降解而失效的难题,采用细乳化聚合方法合成了一种以无机纳米SiO2粒子为联接基、以—C—C—键为分子主链的两亲嵌段聚合物复合纳米降滤失剂NFL-2。—C—C—键分子主链上的吸附基团为酰胺基（20%~30%）,主水化基团为磺酸基（40%~50%）,次水化基团为羧基（10%~15%）,疏水基团为苯乙烯基（0.5%~5.0%）。文中评价了NFL-2在钻井液中的降滤失性能,结果表明：NFL-2在钻井液中的黏度效应小,热稳定性好,抗盐抗钙能力强,用该降滤失剂处理的钻井液在220℃高温老化后其滤失量仍然较低。最后讨论了NFL-2的高温降滤失机理,认为主要是纳米SiO2的高温稳定作用和NFL-2的成膜阻水作用。

Aimed at the the difficult problems that the existing synthetic polymers or natural modified polymer of filtrate loss agent are easy to high temperature degradation and loss efficacy,the fluid loss additive NFL-2 synthetized by fine emulsion method in this paper is a kind of amphiphilic polymer inorganic/polymer nanocomposites taking inorganic nano-SiO2 particles as jointing link and —C—C— bond as the main chain.The —C—C— bond molecular adsorption is amide groups（20%-30%）,the main hydration groups is sulphonic acid group（40%-50%）,the sub-hydration group is carboxyl（10%-15%） and the hydrophobic groups are styrene-based（0.5%-5.0%）.At the same time,this paper evaluates the filtration performance in drilling fluid.The results show that the viscosity effect of NFL-2 in drilling fluid is small,the thermal stability is good and the capability resistant to salt and calcium is strong.The filtration rate of drilling fluid which is handed by the fluid loss additive at maximum temperature 220 ℃ is still low.At last,this paper concludes that the main high temperature fluid loss mechanism of NFL-2 is the stabilizing effect of nano-SiO2 in high temperature and the filming block water effect of NFL-2.