Research Of Emulsion Type Oil Well Cement Additive

The cementing operation is a key link of drilling engineering. Good cementingquality not only provides a basis for subsequent drilling and well completionoperation, also make it easy to increase production efficiency. Without goodcementing quality, the quality of the cement sheath and production schedule will beaffected. Recently, as oil drilling work pays more attention on deep well and ultradeep well, underground environment is becoming more and more complicated. Thenthe requirements for cementing quality enhances unceasingly. Due to the defects ofcement itself, we need to add some cement additives into slurry during cementingprocess to improve various properties of cement.Based on the cementing principles and purpose, this article analyzed the presentsituation and shortcomings of flexibility agent of oil-well cement. Using moleculardesign principle, a core-shell structure emulsion was made through selecting suitableemulsifier, hard monomer, soft monomer and feed way.The monomers of this emulsion are Styrene, butyl acrylate and2-acrylamide-2-methyl propane sulfonic acid. The synthesis method is half continuous.The resultshave shown that the best formula of polymer emulsion is SDS0.5%of monomer, CA1.%of monomer, St:BA:AMPS=1:3:1in seed, KPS0.8%of monomer, stirring rate250r/min, AMPScore: AMPSshell=4:6, neutralization degree70%, reactiontemperature70℃.The structure of this emulsion was characterized by IR and TEM. DSC and TGwere used to characterize thermal stability of the product. Characterization showedthat the St-BA-AMPS emulsion had significant core-shell structure and good heatresistance. This article also discussed the effects of reaction condition on particle sizeand core-shell structure. The effects of synthesized emulsion flexibility agents oncement slurry were analyzed. The results show that core-cell emulsion flexibilityagent can reduce the amount of free liquid and filer loss of cement slurry. ThroughSEM figure, the effect of the emulsion on the micro structure of cement stone wasstudied. The thickening transition time of cement slurry with emulsion flexibility wasshort. Through discussion, this kind of cement slurry can meet the requirement ofcementing requirements.