Study On Water Quality Characteristics And Treatment Limits Of Produced Water From Lipopeptide Ternary Flooding

China is not only a country with poor water resources,but also a big country of water resources.With the continuous development of society,China’s industrial water consumption and urban water consumption continue to increase,and the contradiction between supply and demand of water resources is becoming more and more serious,which has become an obstacle to industrial development and even social development.The reuse of the original system of produced water can not only reduce the waste of water resources,but also reduce the water cost of oil fields.This paper compares the difference between the water quality of the extracted water and the extracted water and the extracted water,understood the water quality characteristics of the viscosity change after the concentration of the extracted water under different conditions,clarified the factors of attention of the extracted water,and formulated the water quality standard for the recovered water.The experimental results show that:（1）Suspended solids,saprophytes,sulfate reducing bacteria,iron bacteria and suspended oil droplets in the extracted water of lipopeptide weak base ternary flooding were significantly higher than those of weak base ternary displacement produced water.Its suspended solids are mainly Oxides of iron and formation mineral particles,and the surface of the particles is wrapped by organic matter,resulting in an increase in particle size;（2）After the polymer is formulated in the produced water,the viscosity will decrease with the increase of time.The main reason for the change in viscosity is the synergistic effect of sulfate-reducing bacteria and iron bacteria in the extracted water,so that the polymer molecules are oxidized,which reduces the viscosity effect;At the same time,the movement of suspended particles and cations and other active substances on the surface will also break the polymer molecular chain,resulting in a decrease in the viscosity of the system.（3）The production water treatment should mainly pay attention to the four aspects of oil content,suspended solids content,suspended solids particle size and bacterial content in the water.The matching degree of suspended solids content with suspended solids particle size and core porosity is the main index affecting the reinjection effect.（4）Different treatment standards for reinjection of extracted water in different strata,For gas measurement permeability 300×10^-3μm²,the oil content in the back water injection should not exceed 10 mg/L and the suspended matter content should not exceed 10 mg/L;Gas permeability of 600×10^-3μm².The oil content in back water injection should not exceed 20mg/L,and the content of suspended matter should not exceed 20 mg/L;Gas permeability of800×10^-3μm².The oil content in back water injection shall not exceed 40 mg/L and the content of suspended matter shall not exceed 40 mg/L;Gas permeability 1200×10^-3μm²formation back water injection oil content should not exceed 80 mg/L,suspended matter content should not exceed 80 mg/L,At the same time,the median particle size of the suspended matter in the extracted water should be less than 6μm.This paper has guiding significance for the formulation of treatment standards for lipopeptide weak base ternary flooded produced water.