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.
References
1. Kolonskikh A.V., Toropov K.V., Sergeychev A.V. et al., Scientific and methodological approaches to improve the development of low-permeability oil reservoirs using horizontal wells with multiple hydraulic fracturing on the territory of LLC RN-Yuganskneftegaz activity (In Russ.), SPE-196755-RU, 2019, DOI: https://doi.org/10.2118/196755-MS
2. Zhang H.-Q., Wang Q., Sarica C., Brill J., Unified model for gas-liquid pipe flow via slug dynamics, J.Energy Res.Techol., 2003, V. 125, pp. 266–283.
3. Zhang H.-Q., Sarica C., Unified modeling of gas/oil/water pipe flow – Basic approach and preliminary validation, SPE-95749-PA, 2005, DOI: https://doi.org/10.2118/95749-PA.
4. Issa R.I., Kempf M.H.W., Simulation of slug flow in horizontal and nearly horizontal pipes with the two-fluid model, Int. J. Multiphase Flow, 2003, V. 29, pp. 69–95.
5. Topol'nikov A.S., Mikhaylov V.G., Yarullin A.R., Teoreticheskoe i eksperimental'noe modelirovanie techeniya mnogofaznogo potoka v gorizontal'nykh skvazhinakh s mnogostadiynym gidrorazryvom plasta (Theoretical and experimental modeling of multiphase flow in horizontal wells with multi-stage hydraulic fracturing), Proceedings of XII All-Russian Congress on Fundamental Problems of Theoretical and Applied Mechanics, Ufa, 2019, pp. 410–412.
6. Beggs H., Brill J., A study of two-phase flow in inclined pipes, Journal of Petroleum Technology, 1973, V. 25, pp. 607–617.
7. Petalas N., Aziz K., Development and testing of a new mechanistic model for multiphase flow in pipes, ASME Fluids Engineering Division 2nd Int. Symposium on Numerical Methods for Multiphase Flows, 1996.
8. Sharma A., Al-Sarkhi A., Sarica C., Zhang C.Y., Modeling of oil-water flow using energy minimization concept, International Journal of Multiphase Flow, 2011, V. 37(4), pp. 326–335.
