TECHNOLOGY OF SALT PREVENTMENT OF W72 S3z FAULTED RESERVOIR IN WENNAN OILFIELD

Salt deposition is severe in oil wells in W72 S3z faulted reservoir, and the composition of salt scale, and reason for formation of salt scale was discussed. Salt scale is composed of Na+, and a small proportion of Ca2+,Mg2+ and HCO3-.FAP and KFN organic scale inhibitor whose mechanism of salt prevent is to change the distribution of electric change on the surface of NaCl crystal, thus destroy the formation of crystal nucleus of NaCl, and prevent NaCl from crystallizing out of solution, by their three acyl-pedestal,-O-and Na+、NHR+ and Cl- attract one another in solution. So, the main functions of salt prevention agent are to incriease solubility of NaCl and to change the crystallizing type of NaCl. Lab study and field test prove the technology is simple, conventient with low cost and good results.