No abstract

Different systems of stratal flooding by mineral or fresh water into oil bearing formation are used today to enhance reservoir recovery. At low temperatures, 25 degrees below zero and lower, there is a great possibility of freezing of the well head equipment due to cyclic flooding or separate horizontal flooding, lessening injection capacity of the well, emergency stops in flooding, due to water pipe breakage or power cutting off. Besides the wells, crossover bends from water injection wells to the pipe header, and stagnation zones of the embedded in grooves pipes can freeze. According to expert estimation of PJSC "Tatneft" specialists, the amount of frozen injection stations is more than 500 wells per year. Due to the urgency of the issue technological measures have been developed to prevent oil-field equipment freezing.

Analysis of advanced recovery methods (ARM) is the most important task in developing an oil deposit. Today, the main part of the geological and technical measures (GTM) is the processing of the bottom holes, particularly in carbonate formations. Their calculation is associated with great difficulty, due to the absence of mathematical models for accounting for factors of a real deposit, which influence the productivity of the well,for example, precipitation of organic salts, asphalt, resin, and paraffin deposits, complex structure of the collecting pipe. Therefore, a new approach to calculating efficiency of advanced recovery methods is required, which would make it possible to take into account properties of a real oil formation 1 .In general, efficiency of the analysis of advanced recovery methods may be divided into the following stages: 1)Calculation of increasing the well productivity coefficient after using ARM, 2)Calculation of water content and defining further dynamics of oil recovery.In the first stage, an instant boost in the well productivity coefficient occurs. This can be achieved by using various models of radial inflow into the well. In this case, some parameters of a real well remain unaccounted for, which leads to significant errors 2 .