Synthesis Of Oilfield Small Molecule Inhibitors

In this paper, three different kinds of small molecule inhibitors were synthesized, includecarboxamide compound, quaternary ammonium salt and glucoside compound. With the linearexpansion rate of bentonite as evaluation index, the synthetic conditions were optimized, and asuitable inhibitor for bentonite was screened. Properties of the inhibitor was evaluated byanti-swelling and shrink swelling experiments, mud ball experiments, mud-making inhibitionexperiments, drilling fluid properties evaluation experiments and clay laser particleexperiments, et al.The inhibitors with organic acids and amines as raw materials performed strong inhibitiveability. Linear swelling ratio of bentonite was impacted by the type of amine, organic acid,mole ratio of the functional group and the mass fraction of inhibitors. DAA-11, DAA-64showed the best inhibitory effect on the hydration expansion and dispersion of bentonite.Linear swelling ratio of bentonite in0.5%DAA-8solution after90min is24.3%, which is43.5%to that of4.0%potassium chloride solution under the same condition. Its anti-swellingrate is39.03%, and shrinkage rate is11.36%. With the bentonite dosage at12%, the dynamicshear force of the drilling fluid treated by DAA-8was23.0972Pa, which is only20.32%to thebase mud. Linear swelling ratio of bentonite in0.5%DAA-8solution after90min is60.97%,which is similar to that of4.0%potassium chloride solution under the same condition. Itsanti-swelling rate is63.33%, and shrinkage rate is33.33%. The dynamic shear force of thedrilling fluid treated by DAA-64was1.3286Pa, which is1.17%to the base mud. The screenedinhibitors showed thicken ability and good compatibility with KD-03and modified starch indrilling fluid at room temperature.The inhibitors synthesized by melamine and sodium chloroacetate also performedinhibitive ability on the hydration expansion and dispersion of bentonite. Linear swelling ratioof bentonite in0.5%MAA-3solution after90min is57.37%, and its shrinkage rate is22.73%.The dynamic shear force of the drilling fluid treated by MAA-3was40.7160Pa, which is35.83%to the base mud.The glucosides compound that synthesized by four methods showed stronger inhibitive ability than methyl glucose. Linear swelling ratio of bentonite in10.0%TG-1solution after90min is54.62%, which is less than that of4.0%potassium chloride solution under the samecondition. Its anti-swelling rate is79.07%, and shrinkage rate is10.84%. With the bentonitedosage at12%, the dynamic shear force of the drilling fluid treated by TG-1was70.6480Pa,which is62.16%to the base mud.