Study On A Cementing System For Cementing And Strengthening

Under all kinds of complicated conditions of geology and operarting, long time sealing was necessary for the cementing paste of underground gas storage.So that the cementing slurry system was obliged to have the abilities of well mechanical and sealing integrity. One of the most important problems of cementing design was the cementing materials. And the oil cement slurry system was the major and significante cementing materials. With inborn flaws in microstructer of the portland cement that had seriously confined the performance and application of the cementing slurry system. So it was necessary to develop the mechanical performace of the cementing pastes of underground gas storage and it was remarkable to ensure the safty of long time working. Carbon fiber, polyester fiber, brucite fibre, calcium carbonate whisker and re-dispersible emulsoid powder as five cement paste modifing materials were tested and opertimized under the investigations of the research status and experiment condition detailedly. According to the characteristics of each material, the dispersion methods had been explored and the fluidity, API water-loss and stability of each kind of toughening slurry was also tested to gain the experiment formulas.The compressive strength, flexible strength, splite tensile strength, uniaxial and triaxial mechanics experiments of each kind of material were tested and analysed in the paper. Also the best dosages were acpuired.The cement paste with both Carbon fiber and calcium carbonate whisker, polyester fiber and calcium carbonate whisker had been reaserched as well. The normal mechanical properties, elasticity modulus, stress-strain curve and mixed coefficient of composite material with two fibers of all the experiment formulas were discussed in this paper. By using the electron scanning microscope, the microstructure of each toughening paste had been surveyed and analyzed to elaborate the toughening mechanism. The fomulas of both with carbon fiber and calcium carbonate whisker, polyester fiber and calcium carbonate whisker could develop the noramal mechanical properties and decrese the elasticity modulus were introduced as primary fomulas for the underground gas storage. The improving suggestions of the toughenting cement slurry were also put forward.It was establish a foundation which could exploit and improve the cement slurry system of underground gas storage.