The Present Research Situation and Prospects about the Cement Sheath Defect Affecting on Connection Strength of Casing

At present, in domestic and foreign cementing process, there is often a cementing quality without qualified. The cement sheath defects caused by too low displacement efficiency and gas channeling, will greatly reduce the casing bearing capacity, reduce the service life of the casing, so studying about cement sheath defects affecting on casing strength is very important. Through access to a large number of reference, summarizes the currently, at home and abroad, researches about cement sheath defects affecting on casing strength, analyzes the main technical difficulties faced by, and looks forward to the development trend of the research, point out that we should bind site cement sheath defects with actual situation, build a more close to the reality of cement sheath defect model, establish a set of more perfect cement sheath defects research system for influence on casing strength to further improve the cement sheath defect morphology. In order to improve the research level of the casing strength, the laboratory experiment and field investigation, computer tomography technology and computer aided software technology are studied in the paper.