Research On Green And Hi-efficient Scale Inhibiting-dispersing Agent And Its Application In Oilfield

The scale deposit rises from a normal problem in the production of oilfield. The main scaledeposits in waterflooding system contain carbonates, sulfates, oxides, and organiccompounds.The scale from the ASP flooding is a kind of complicated mixed deposit most ofwhich are silicate. The existence of the scale deposit reduces the productivity, increases theproduction costs and restricts the highly efficiency and low cost for development of the oilfield.The water-soluble inhibiting-dispersing agent was prepared by radical polymerization inaqueous solution, by using iron salts as catalyst and H₂O₂-NaH₂PO₂ as initiator. Maleicanhydride (MAA), acrylic acid (AA) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS)were employed as monomers for synthesis of the copolymer. The effects of monomer, initiator,reaction time and temperature on the performance of the copolymer are studied.The experimentalresults show that the optimal processes are followed as 0.7:0.30:0.03:0.20:0.7 of molar ratio ofMA :AA : AMPS : NaH₂PO₂ : H₂O₂, 105℃ of reaction temperature, 1.5h of titration time and2.0h of reaction time. The FTIR spectra of the product show that there are carboxyl, hydrosyl,ulfonic, phosphoryl and the other functional groups.The experimental results show that the scale inhibiting-dispersing Agent prepared in theoptimal process has excellent performance in : (1) thermal stability to 100℃;(2)great propertyunder high pH value ( pH=12);(3) the low dosage and high efficient with 94.0% of the scaleinhibition efficiency to CaCO₃ by 5mg/L SY-1# in the system, and 35.5%(T) of the dispensabilityto ferric oxide;(4) good compatibility of SY-1# to oilfield chemicals;(5) high inhibition ratio ofin 85.0%of SY-1# to the scale deposit of ASP flooding;(6) efficient corrosion inhibition by 20%,85.0% at SY-1# of 10mg/L and 50mg/L;⑦friendly environment without pollution in aqueouspreparation.The field tests show that the SY-1^# is efficient for the ASP flooding scale deposit. The non-trouble during for pump was prolongated by using SY-1^#.