Research On Application Technology Of Cementing Casing Centralizer

In the process of cementing the directional well,the casing is one of the important factors affecting the quality of cementing.To improve the casing centralizer,the use of casing centralizer.Different types of casing centralizer due to the different structure and characteristics of the casing and the central device installation distance is different,casing into the process of friction is also a big difference.Therefore,it is of great significance for the directional wells,especially the large displacement wells,to determine the appropriate casing centralizer and installation distance,for the smooth entry of casing and improve the quality of cementing.Based on the research of domestic and foreign literatures,this paper analyzes the structure and characteristics of the conventional coin-stiffener,and points out that the use of rigid sleeve stiffener is limited,the hydraulic casing central device has the advantages of complex structure,poor controllability,The flexible sleeve centralizer is simple in structure and has more applications in the field.Under the casing,the elastic resistance of the sleeve can be further reduced,so that the depth of the casing can be further increased.Based on the analysis of the structure of the existing elastic casing centralizer,this paper has improved the structure of the flexible sleeve centralizer,using the hard plastic material with low coefficient of friction as the support block in contact with the borehole wall.The coefficient is about one-tenth of the coefficient of friction of the spring piece of the original resilient bushing centralizer,the use of two-dimensional drawing tools to design the hard plastic parts of the block and the improved elastic sleeve stiffener,improve the structural design application By the national utility model patents(patent number: ZL201621089458.X).Considering the influence factors of the difference between the inside and the outside of the casing,calculate the load,and refer to the oil and gas industry SY / T5334-1996 standard method,and correct the installation spacing of the casing centralizer to make the calculation and calculation of the elastic sleeve stiffener spacing more suitable for engineering actual.On the basis of this,the calculation program written in VB language can realize the fast calculation of parameters such as friction resistance and installation spacing under casing reducer,which has certain guiding significance for the optimization of casing and the operation of casing The friction coefficient of the original elastic sleeve stiffener and the improved elastic sleeve stiffener is calculated by combining the engineering actual well Cao Ping6 well and Nan Hua 1 well.The results show that the improved elastic sleeve stiffener Frictional resistance reduced the original 90 percent,more conducive to the directional wells,large displacement well casing operation smoothly.