Research On Improving Polymer Solution Viscosity Prepared By Sewage Containing Fe²⁺ And S^2- And Viscosity Reduction Mechanism

In the paper, aiming at the problem that polymer viscosity is not high prepared by sewage containing Fe²⁺and S^2-in gu-dao Ng3-2 district and Sheng-Tuo T28 district, factors causing viscosity loss of polymer solution were studied; The mechanism of reducing viscosity were analyzed by viewing the SEM 、 infrared spectroscopy（IR） 、 the viscosity average molecular weigh、fluorescence spectrum figure and dynamic light scattering（DLS） before and after adding Fe²⁺and S^2-in mineralized water; and the method of eliminating Fe²⁺and S^2-was studied, what’s more, ion shield agent and stable viscosity were selected on the basis of the problem that polymer viscosity stability is not high prepared by sewage, then mixed up with reagents according to water quality of the experimentation area block, developed effective water treatment formula effectively.The performance of ordinary type and hydrophobically associating polymer were studied,the results showed that the property of hydrophobically associating polymer solution was superier in the viscosifying characteristics, temperature resistence, salinity resistence. The effect of non reducing ion(Na+, Mg²⁺, Ca²⁺) on hydrophobically associating polymer is small;but the influence of reduction ions(Fe²⁺, S^2-) on the two kinds of polymer solution viscosity,Two kinds of polymer solution viscosity were decreased rapidly by a small amount of Fe²⁺;when S^2-<1 mg·L-1, the effects on two kinds of the polymer solution viscosity is very small,S^2->1 mg·L-1, the effects on two kinds of the polymer solution viscosity is great. Fe²⁺/S^2-breaks the polymer molecular chain, forming C=C small molecule substance, reduces the polymer viscosity average molecular weight, destroys the association network morphology among the molecular in polymer solution, so that polymer solution viscosity is decreased.The methods of oxidation, complexation and precipitation on dealing with Fe²⁺, S^2-were studied aiming at the problem that Fe²⁺, S^2-induce polymer solution viscosity decrease. The results showed that the effects of Potassium Permanganate oxidation method on treating with Fe²⁺, S^2-and precipitation methond on treating with Fe²⁺are remarkable; The ion shield WN was filtered aiming at the problem that polymer solution viscosity stability is not high caused by the Ca²⁺, Mg²⁺, and the optimal dosage is 200 mg·L-1.3 mg·L-1Fe²⁺is the main factor to affect the polymer solution viscosity in gu-dao Ng3-2district, Ca²⁺, Mg²⁺make the polymer solution viscosity and stability decrease; composite water treatment formula ZW was developed and thickening rate reached 130.5 %, the viscosity retention rate is 85 % after 60d; 5.9 mg·L-1Fe²⁺made polymer solution viscosity decrease sharply in Shengtuo oilfield T28 district, and the polymer solution viscosity decreased nearly 70 % after 60 d; Potassium Permanganate oxidizes Fe²⁺, thickening rate was258 %, the viscosity retention rate was 76.3 % after 60 d; precipitation method was also available on dealing with Fe²⁺, thickening rate was 400 %, the viscosity retention rate was78.2 % after 60 d.