Research And Application Of Effect Of Typical Mineral Materials On The Cement System

The fine quality of cement slurry system is the effective guarantee for cement sheath in long term valid envelopment and high efficient development of field. The primary goal of this dissertation is improve the quality of cement slurry system that are used in high temperature deep well. This dissertation aims at the characteristics of cement admixture that consisting of oil well cement,well cement admixture and well cement additives. The impact on cement slurry system of powder packing density,well cement admixture and well cement additives has been comprehensive studied. This dissertation study and discovery the cement admixture that is helpful to improves cementing quality of high temperature deep well.Firstly, the type, characteristic feature, application scope of high packing density theory was discussed in this paper. Gradation of commonly used micro-powder and well cement was studied in this Dissertation.With the guidance of Compressible Packing Model and Andreasen equation,the dense packing effect of micro-powder gradation on cement slurry system was researched,and the grading effect of micro-powder on rheological and hardening properties of cement slurry system was also discussed. The differential distribution of particles of raw material is calculated when packing system reaches the closest packing. And then,differential distribution curve of particles of mixture with various contents is compared with differential distribution curve of particles under the closest packing.From the idea of Andreasen equation,the closer the particle differential distribution of mixed system compares with that of the closest packing system,the higher the density of system is,which is in good agreement with the calculation results of CPM model. Comparing characteristic feature and application environment of cement slurry system with High Performance Concrete, this dissertation suggests that high packing density theory of cement slurry system should take cementing requirement and the impact on cement slurry system of well cement admixture and well cement additives into considertion. Proper and appropriate powder packing density is of vital importance to cement slurry system.In the lab experiments,the influence of type,dosage,partical size distribution and chemical reactivity of admixture on rheological behaviour, mechanical properties, volume shrinkage, static gel strength development, thickening time and stability of cement slurry system had been investigated, The hydration products of the cement admixture was analyzed and studied in detail by using equipment as XRD and SEM etc,the hydration characteristic of the admixture and strength characteristics are revealed. It puts forward the law that the factors as grain fraction,component addition,water-cement ratio etc.of weighting material,silica powder, light-weight additive and other additives affect the engineering capacity of cement slurry system. Research results offer experiment support for Establish standard about weighting material. By means of mercury Penetration test, this paper analyzes the action mechanism of NS on cement slurry from the micro aspect.The microstructure of paste with NS is compacter than that without NS. Adding NS can reduce the content of C-H in the Paste, and refine the C-H crystal in large size. As for the cement slurry without NS, the C-S-H gel at the interface is mainly in the compact cluster and dense net structure. Adding NS can improving the micro characteristics of cement slurry,and enhancing and improving the macro performance of cement slurry.This dissertation dealt with the synthesis of the AMPS terpolymer as a temperature-resistance, salt-tolerance fluid-loss additive and retarder, which used 2-acrylamido-2-methylpropanesulphonic monomers and initiated a new type of the azonic initiator. Optimal condition of the synthesis determined through orthogonal experiments were proposed. The structure of the terpolymer was confirmed by infrared spectrum(IR) analysis. Differential scanning calorimetry(DSC) and thermogravimetry(TG) tests showed that a good thermo-stabilization of the terpolymer could be maintained at 300℃.In this dissertation, the combination of the well cement admixture and well cement additives is applied to the oil industry cementing technique.Through the further research on chemical properties of well cement admixture, the influence law of cementing system performance and strength at different ratio gel system is analyzed, It puts forward new approaches and design method of cementation cementing slurry system to satisfy regular cementing operation requirements. The cement slurry system used in Xinjiang low pressure and easy leaking wells and high temperature prospecting wells, those applications is well.