Perm Journal of Petroleum and Mining Engineering (Mar 2020)
Preventing and eliminating wellcompletion problems
Abstract
The article reflects the importance of improving the quality of oil and gas well completion. The problem of improving well operational efficiency sets the requirement for a high-tech approach to solving the whole range of tasks from the design and construction of an oil and gas well to its completion, workover and abandonment. The article mentions the major problems arising at the well completion stage. In particular, it provides a review of poor-quality cementing consequences, including the formation of filtration channels resulting in a cross-flow and increased watercut; the contraction effect; and the mismatched cement compositions that affect the formation isolation and the oil, gas and water showing. The authors outline the methods for repair and renewal operations aimed at well uploading. In addition, they show existing technologies for recovering well casing integrity during remedial insulation, as well as the methods to improve the quality of a well casing at its construction. Moreover, the article presents the developed technology of temporary aquifers in-process isolation with compositions of viscoelastic systems. Studying water shut-off techniques for the existing wells determines the focus for the scientists, who work on creating new and improving the existing blocking agents to get better result from their application and lower operational costs. The authors recommend using the advanced compositions of viscoelastic systems to shut-off aquifers while drilling. In order to strengthen the cement stone and, as a consequence, the well casing, the following fields could be proposed for further study: upgrading the cement slurry quality with carbon additives, such as soot, carbon black, graphite, oxidized graphite, graphene, graphene oxide, and carbon nanotubes.
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