The Compatibility of Polymer--Flooding Wastewater and Fresh Injection Water in LD10--1 Oil Field.

The mixture of fresh water from Guantao formation and purified polymer--flooding wastewater without any additives was used as source of injection water in LD10 -- 1 Oil Field. For the purpose of reservoir protection and damage prevention, according to industry standards SY/T 0600 --1997, the different scaling tendency of mixture was predicted. The alligate solids gained from the mixture were studied. The results are shown as follows: there are more suspended solids after mixed fresh water with wastewater, and the compatibility is the worst when the mixed ratio is 1 : 1; the X -- ray analysis indicates that there are CaCO3 character peaks in the suspended solids. The micro structure of suspended solids was studied by ESEM and AFM, the result shows that the suspended solids in fresh water are precipitated without regularity and formed crystal particles with a diameter of 50µm; when the mixed ratio is 1 : 1, the suspended solids are homogeneous precipitated with a diameter of 0. 5µm ~ l. 0µm;. The integrated researches indicate that he retained polymer in wastewater can restrain the formation of CaCO3 scale and megacryst. The fresh water containing high amount of Ca2+ and Mg2+ can enhance the aggregation of retained polymer. [ABSTRACT FROM AUTHOR]