At the present stage of oil production the share of hard-to-recover carbon reserves reaches 65% of the total volume of proven reserves and continues to grow up. One of the most effective methods of recovery of hard-to-recover reserves are the horizontal wells with multiple hydraulic fracturing, which operating needs to conduct permanent monitoring including the control of intensity of inflow from the hydraulic fracturing ports and the definition of phase content of the flowing fluids. Among the most widespread methods of oil production monitoring in horizontal wells with multiple hydraulic fracturing the field geophysical surveys are standing out. At the present time the cost of field geophysical surveys is rather high and the interpretation of the surveys is not always unambiguous. In this sense the development of technologies in the structure of Rosneft software is actual for increase of efficiency of surveys and reduction of the operation costs.
In the paper the results of research of multiphase flow in the horizontal well shank with multiple hydraulic fracturing for resolving the problem of inflow profile and fluid content determination are presented. The original mathematical models are developed for description of stationary and non-stationary flow of mixtures of liquid-gas, oil-water and water-oil-gas in horizontal and near horizontal tubes, which expand the present methods of prediction of the pressure and temperature gradients and phase concentrations. The experimental stand is constructed, which contains the transparent tube of 12 meters length with inner diameter of 94 mm, with possibility of regulation of angle of inclination of its separate sections and inflow of liquid and gas in two different points. At the experimental stand the comparison of measured and calculated liquid holdup is carried out for the mixtures of water-air and oil-water and different flow rates of mixture components and angles of inclination. The satisfactory agreement was gained and it was shown that the developed mathematical models exceed in accuracy the known methods, which are realized in commercial software. On the base of the models the algorithm is constructed to determine the inflow profile and the phase content based on the measured parameters of multiphase flow in the horizontal well shank with multiple hydraulic fracturing. The program module is realized for interpretation of results of the field geophysical surveys.
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