用螯合剂抑制表面活性剂驱油过程中石油磺酸盐的沉淀损失

CONTROL OF THE SULFONATE PRECIPITATION IN SURFACTANT FLOODING BY CHELATING AGENT

本文研究了不同模数和浓度的硅酸钠抑制石油磺酸盐与多价阳离子的沉淀作用的能力。研究表明,硅酸钠主要是通过对多价阳离子的螯合而起抑制作用的,不同模数的硅酸钠对多价阳离子的螯合能力不同,随着硅酸钠的模数或浓度的增加(在一定范围内),石油磺酸盐的沉淀损失逐渐减小。

In surfatcant flooding,sulfonate will react with multivalent cations existing in the for- mation water to produce sulfonate precipitation,which is harmful to the flooding process. In order to control the sulfonate precipitation,sodium silicate was regarded as a chelating agent to chelate multivalent cations.TRS10-80(sulfonate)and calcium ion system was studied in this paper. The controlling ability of sodium silicate to the sulfonate precipitation varies with their modul.The higher the modul of sodium silicate,the stronger their controlling ability to the sulfonate precipitation,mainly because of the increase of the percent content of SiO_2 and the negative charge density of sodium silicate along with the increase of their modul. The controlling ability of the same modul sodium silicate to the sulfonate precipitation varies with their concentration.In a range of concentration,the higher the concentration of sodium silicate,the stronger their controlling ability to the sulfonate precipitation,mainly because of the increase of the silicate on number that can chelate multivalent cation along with the increase of their concentration.Moreover,sodium silicate addep-would lead to the increase ofbasicity of the sulfonate solution and the decreaseof the sulfonate precipitation.The concentration of sodium silicate added should not be too high,otherwise silicate gel would take place.