Synthesis Of Novel Aminocarboxylate Complexes And Their Removal Of Sulfate Scales

In the process of oil and gas exploitation in oil field,some wells were blocked by sulphate scale,resulting in serious economic loss.At present,the most effective method for inhibiting and dissolving sulphate scale is chemical method.EDTA is widely used as main agent in dissolving the sulfate scale for effective chelating behavior and because the other chelating cetergent are expensive.In this article,a new more ligand aminoxatyl complexing agent-named TTAHA is synthesized considering the molecule structure of EDTA,and taking it as main dissoving agent of the new scale dissolving coupound TEG-SD that is of theoretical and practical value.Through single factor experiment method and the orthogonal experiment optimization,the best condition for synthesizing is confirmed,the dissolved scale amount could approximately be 0.28g using the best conditions for synthesizing TTAHA.The structure of TTAHA is confirmed by using infrared spectrometer.The dissolving ability of TTAHA is better than EDTA by contrasted with EDTA and the blank.Then the chelating capacity is checked by turbidimetric.In order to improve the ability of dissolving scale,TTAHA is taken as main dissoving agent for research the effection of scale dissolver.A new multi-carboxyl sulfonic acid polymer PAMA have been designed and synthesized,that is a kind of low molecular weight polymer.Then the structure of PAMA is confirmed by infrared spectrometer which is same as designing.When using 100mg/L PAMA,the scale inhibiton ablity and suspension ability for barium sulfate is good,proving PAMA have good chelation and dispersion ability.In the common complexes,EDTA have been taken as the sec-chelating agent,and sodium gluconate as adjuvant,the dissolved scale amount approximately is been increased to 0.42g.The scale dissover TEG-SD’s recipe is confirmed:sodium gluconate,EDTA,TTAHA mass ratio is 5:1:5,the solution concentration of PAMA is 100 mg/L.The applicative condition of TEG-SD have been researched in following factors,concentration,temperature,operation time and pH value which have influence on effection of dissolving scale,but the concentration of salinity does little effection on that.The results proved that TEG-SD have a long duration time and low dissolving temperature.TEG-SD have both the scale dissolving ability and the scale inhibition ability,the scale dissolving ability varied with the number scale solubility,and the scale inhibition ability is better than the scale dissolving ability,the dissolved scale amount approximately is been increased to 0.43g.In addition,TEG-SD have a certain corrosion inhibition ability.In conclusion,TEG-SD is an excellent comprehensive performance scale dissolver.According to the molecular structural characteristics of the main chelating cetergent TTAHA and sec-chelating cetergent EDTA,and the double electrical layer effect of the dispersant PAMA,the fouling mechanism of TEG-SD have been analysed.The main scale dissolving principle is chelation and adsorption dispersion effect.