The qualitative fastening of the shanks is one of the most urgent problems at sidetracking, especially in the case of high water cut of entering formation, and a necessary condition for long-term and accident-free operation of wells for various purposes. The main factors affecting the fastening quality are considered.
Specialists of the Fedorovsk Department of EOR Methods and Wells Workover are carrying out complex work aimed at improving the technology of sidetracking and minimizing the impact of negative factors on the further operation of the well. Combating overflows is carried out by forecasting and analyzing various data obtained both at the planning stage and during the work on the well. To ensure the reliability of the forecast, at all stages of sidetracking, statistical data are collected on the state of the well and the deviations of the technological process from the planned sidetracking and shank fastening programs. To reduce the number of operators in the analysis of data, the shank fastening quality factor was introduced, which allows with high accuracy to predict the behind-the-casing flow before the well development work. As an example, the behind-the-casing flow is considered in wells No. 1053 and 3230 of the East Surgut field and in wells No. 4289 and 865 of the Sarymo-Russkinskoye field. Taking into account the results obtained analytically, experimental works were carried out to determine the actual pressures at which the cement ring is destroyed.
Analysis of the results of computational studies and practical experiments has shown that it is not possible to exclude the behind-the-casing water flow only by changing the formulation and composition of plug-back mixtures. Prospective directions of works are outlined.
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