One of the most simple, inexpensive and frequently used hydrodynamic methods of enhanced oil recovery is cyclic waterflooding. Despite the development of hydrodynamic modelling technologies, the prediction of the cyclic flooding efficiency remains a challenge. Due to the rapid flow of filtration processes during cyclical waterflooding, the calculated time step needs to be chosen much smaller than when simulating stationary flooding. Therefore, the simulation of cyclic flooding using a hydrodynamic simulator takes much more time, which may be unacceptable in practice. Without taking into account this limitation on the time step, the calculated efficiency will be unreliable (usually close to zero).
The selection of optimal values of the cyclic waterflooding parameters usually requires multiple simulation runs. To reduce the number of simulation runs that require significant time we proposed an effective technology for simulating cyclic waterflooding based on the ‘top-down’ concept. The process is divided into stages, including selection of promising areas from the point of view of additional oil recovery and parameters characterizing the cyclic impact on the reservoir. The technology allows us in real time to select prospective areas and perform an assessment of the impact on the additional oil production of the location of the wells, the period and duration of the cyclic action, and the like.
The advantages of the proposed technology in comparison with analogues are demonstrated, as well as the results of its successful application in some oil fields of Western Siberia and Kazakhstan.
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