Provision of high quality of well cementing is a multifactorial problem, and the solution to this problem should be approached comprehensively. During the analysis and generalization of actual geological, geophysical and technical-technological data on the oil fields of the Republic of Tatarstan the main reasons of low-quality cementing of wells were revealed: - non-observance of design solutions - violation of technological operations; - absence or destruction of cement behind the production string; - absence of chemical reagents for cement slurry; - low provision of technological casing equipment. In order to improve the quality of well casing and to fully or partially eliminate the above drawbacks, the technology of forming impermeable cement screen in the wellbore area during construction and repair of wells and technical means (TS) for external casing string tooling have been developed with the participation of the author of the article. As a result of applying the technology and using TC at the oil fields of the Republic of Tatarstan significant economic and technological effects were achieved.
