Synthesis Of Polymer Additives And Their Applicate In Oil Well Cement

Well cementing is a key process in oil and gas well drilling and completionproject, especially in deep and ultra-deep well. Well cementing quality is related tothe well drilling and following completion, oil production and well repairing. With thedevelopment of oil exploitation, oil exploration toward to the deep, ultra-deep, andspecial well, which put forward higher requirement for the cementing operation.Adding a certain kind and amount of oil well cement additives to improve theperformance of all aspects of oil well cement is one of the key technologies ofcementing operation. Compared with the advanced world level, we have a juniorresearch on oil well cement additives. Based on the principles of molecular design inthis dissertation, AMPS kind of water-soluble polymer HTR-200C is designed andsynthesized. And HTR-200C is used as high temperature and salt resist retarders,which solve the problems of retarders we already use now, such as slurry systemunstable, strong dispersion, poor retardation and salt resistance at high temperature.And new kind of latex polymer HTL-200C is designed and synthesized by soap-freeemulsion polymerization. HTL-200C is used as high temperature and salt resisttoughener, which solve the problems of toughener we already use now, such as oversensitive to temperature and salt content.A series of water-solubel polymers are synthesized by free radical solutionpolymerization utilizing such monomers as2-acrylamide-2-methlpropane sulfonicacid (AMPS), methacrylate (MAA), fumaric acid (FA) and maleic acid (MA). Thispolymer is used as oil well cement retarder, and through designing orthogonalexperiments and optimizing the ratio of the monomers, the amount of initiator, pH,temperature of polymerization, the optimal retarder is found. And the production isnamed HTR-200C. The structure and thermal stability of the copolymer wascharacterized with IR, DSC and TG. And the high temperature retardation,compatibility with other cement additives and the effects of those properties oncompressive strength of cement were evaluated. In additional, HTR-200C retardedmechanism was also analyzed. The results demonstrate that HTR-200C can be used at180℃, excellent retardation, controllable thickening time, an ideal thickening curve, transient time is short on thickening curve, no effect on compressive strength, andgood compatibility with other additives.A series of latex polymers are synthesized by soup-free emulsion polymerizationutilizing such monomers as2-acrylamide-2-methlpropane sulfonic acid (AMPS),styrene (St), butyl acrylate (BA), methacrylate (MAA), and itaconic acid (IA). Thispolymer is used as oil well cement toughener, and through designing orthogonalexperiments and optimizing the ratio of the monomers, the amount of initiator, pH,temperature of polymerization, the optimal retarder is found. And the production isnamed HTL-200C. The structure and thermal stability of the copolymer wascharacterized with IR, DSC and TG. And free water, fluid loss, compressive strength,ruptures strength, salt-resistence, gas channeling prevention are evaluated. Inadditional, HTL-200C retarded mechanism was also analyzed. The resultsdemonstrate that slurry with HTL-200C have properties of temperature-tolerance,salt-resistance, low fluid loss, zero free liquid, great gas channeling prevention, thethickening curve emerged right angle with short transition period and exellent toughenperformance.