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We continue to intensively study the flow of suspension in the vicinity of injection wells, with the focus on colmatation and particle mobilization in the near-wellbore zone. The key application is the design and planning of operations on improvement of injectivity during water flooding to maintain the reservoir pressure for efficient production. The key phenomenon in focus is formation damage. A 1D three-continua model is used for suspension filtration to describe the permeability damage in the near-wellbore zone. In contrast to the models known from the open literature, the present model is constructed in the multi-continua approach. The carrier phase, the suspended particles, and the trapped particles are considered as three different media. The application of the multi-continua approach allows one to reduce the number of free tuning parameters, which require calibration against experimental data. The model takes into account the effects of trapping of particles in pores (colmatation) and mobilization of particles when the flow velocity exceeds a certain threshold. We continue the calibration and tuning campaign started earlier on a vast amount of various laboratory data on suspension flows in porous medium (core flooding experiments).

Simulations are conducted to evaluate the reduced permeability, the concentration of suspended particles and the concentration of trapped particles in pores in the near-wellbore zone. In addition, we calculated the integral skin-factor as a parameter characterizing the colmatation of the near-wellbore zone. A parametric study is carried out to investigate the colmatation of the reservoir in the course of a cycling injection regime where long periods of water injection are interchanging with short periods of production. A free parameter of the model (the colmatation coefficient) which characterizes the intensity of the particle trapping in pores depends on the combination of the properties of the porous medium and the particles (including characteristic size of the pores and the particles). To sum up, we propose the model of multiphase filtration, which takes into account particle trapping in pores (colmatation) and particle mobilization. The tuning parameters of the model are the colmatation coefficient, which characterizes the intensity of particle trapping in pores, and the mobilization coefficient determining the particle mobilization rate. The model went through substantial validation on lab data. The prototype of the simulation kernel allows one to optimize the regime of flooding on injection wells and also to select optimum properties of the particles, fluid, and injection/production rates to avoid dramatic decrease in the injectivity of the injection wells, which occurs due to the permeability damage in the near-wellbore zone.