降滤失剂H-QA的制备与性能评价

为进一步改善腐植酸类产品在油包水乳化钻井液中的抗温能力、分散能力和降滤失能力，采用十八烷基三甲基氯化铵对腐植酸进行改性制备降滤失剂H-QA，用作低毒油包水乳化钻井液降滤失剂。探索了合成条件对降滤失剂性能的影响，按照石油天然气行业标准评价了其在低毒油包水乳化钻井液中的性能。结果表明，降滤失剂H-QA的最佳合成条件为:反应物的配比KHu（腐植酸钾） : 1831（十八烷基三甲基氯化铵）为 3 : 1，反应体系pH=8.86，反应温度40 ℃，裂解反应时间4 h。降滤失剂H-QA在加量为4%时，常温中压滤失量从6.4 mL降到4.0 mL，150 ℃高温高压滤失量从8.6 mL降到6.8 mL，在油包水乳化钻井液中具有明显的降滤失效果。此降滤失剂对钻井液流变性影响较小，有较好的分散能力，具有一定的应用和研究价值。

Synthesis and performance test of fluid loss additive H-QA

To further improve temperature resistance, dispersion ability and filtration reduction of fluid loss additive in water-in-oil emulsion drilling fluids, fluid loss additive H-QA was prepared by the reaction of humic acid with octadecyl trimethyl ammonium chloride, to use in low toxicity water-in-oil emulsion drilling fluid. The influence of synthetic conditions on the fluid loss additive properties was explored, and the properties of fluid loss additive in low toxicity invert oil-emulsion drilling fluid were evaluated according to the petroleum and national gas industry standards. The results of optimal synthetic conditions were showed as follows: the ratio of potassium humate to octadecyl trimethyl ammonium chloride （1 831） is 3﹕1, pH of the reaction system 8.86, reaction temperature 40℃, scission reaction time 4h. When addition of H-QA is 4%, the API filtration reduced from 6.4 mL to 4.0 mL, the HTHP filtration reduced from 8.6 mL to 6.8 mL. It shows a good fluid loss control effect in water-in-oil emulsion drilling fluid. No influence on drilling fluid rheology was noticed by addition of the fluid loss additive, which has certain application and research value.