Synthesis And Properties Of MA/SSS/SH16 Terpolymer Barium Sulfate (?) Scale Inhibitor MSH

This study synthesized a new type of terpolymer scale inhibitor MSI I.During the molecular structure design of this inhibitor,not only the three common mechanisms of inhibition are used,but also introduced the steric hindrance and hydrophobic effect into it.Synthesis experiments are using Maleic anhydride(MA),Styrene sodium sulfonate(SSS)and a hydrophobic monomer SH16 to conduct.The method of polymerization is aqueous solution polymerization.Single factor method is used to determine this experiment's optimum reaction conditions.The conclusions are,monomer molar ratio is SSS:MA:SH16=700:900:1,initiator dosage is 5 wt%,the reaction temperature is 70?,monomer concentration is 35 wt%,the reaction time is 12 h.The structure of the product were characterized by FT-IR and 1H NMR.Analyzed two spectra can be concluded that the structure of product is the structure designed before.The TGA analysis shows that MSH has a good thermal stability.Static scale experiment of MSH's results indicates it has good scale inhibition ability,especially for BaSO4 scale.For BaSO4 scale:when Ba2+ concentration is 370mg/L,50mg/L of MSH's inhibition efficiency is 90.8%.For SrSO4 scale:when Sr2+ concentration is 1500mg/L,30 mg/L of MSH's inhibition efficiency is 94.0%.For different molar ratios Ba2+(Sr2+)and SO42-,MSH can also achieve good inhibition efficiency.Acidic environment have a bad impact on the performance of MSH.MSH has good temperature resistance and salt tolerance.The results of MSH's simulation the dynamic scale inhibition experiment show that it can effectively reduce the damage of water injection operations on formation permeability.Water injection operation caused damage decrease rate from 33.68%to 26.46%after adding 5 mg/L of MSH.In addition,it decreases to 9.31%when adding 20mg/L of MSH.SSS/MA and MSH's scale inhibition performance comparison results shows that MSH performs better than SSS/MA.It proved that after adding SH16 into the molecular structure of MSH,the long hydrophobic chain of SH16 molecules enhanced scale inhibition performance of MSH by steric hindrance and the hydrophobic effect.MSH affects the crystallization process of BaSO4 and SrSO4 were studied by conductivity method.The results show that MSH can effectively extend the induction period of the two crystals crystallization process.It also can slow down both of the speed of nucleation and speed of grain growth,especially the nucleation rate.The results of SEM and XRD research show that MSH has significant interference on the growth of the two crystals.MSH can reduce the crystallinity of the two crystals,occurs lattice distortion,crystal grains get smaller and less.Its mechanism is MSH involved into two crystal's lattice by adsorption,disrupt the normal sort crystal lattice,make the crystal cannot be grown in accordance with the original order,crystal growth becomes abnormal shape.At the same time,MSH molecule doped on the surface of the two crystal can reduced the mutual attraction between crystals by the steric hindrance and hydrophobic effect,so that they can not be aggregated into a dense crystals,eventually becomes loose scale and confusion arrangement.