PSI - Issue 37

A. Kostina et al. / Procedia Structural Integrity 37 (2022) 431–438 A. Kostina/ Structural Integrity Procedia 00 (2019) 000 – 000

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using External Stress node for effective stress, Thermal Expansion node for thermal strain, Plasticity node for plastic strain and Gravity node for gravity force. 4. Results of numerical simulation To investigate the effect of rock dilation on oil recovery rate we will consider steam-assisted gravity drainage in a thin part of a formation with a thickness of 4 cm, a width of 20 m, height of 20 m. It should be noted that in this problem we don’t consider production well and apply an enlarged radius of steam injection (0.5 m) to exclude large stress concentrators. The reservoir properties correspond to the Yarega oil deposit (Russian heavy oil deposit in Komi Republic). The temperature and the pressure of the injected steam were equal to 493 K and 1.6 MPa respectively. Outflow boundary condition for water and steam saturations was set on the boundary of steam injection. Roller boundary conditions were applied for front, rear, left, right boundaries of the reservoir. The bottom of the formation was assumed to be fixed. Figure 1 shows the final temperature distribution obtained for the plastic and thermo-elastic problems. It can be seen that in the case of the plastic problem steam chamber propagates faster and almost attains the bottom of the layer while the steam chamber for the elastic problem is only at the beginning of the downward stage. Figure 2 presents final distributions of oil saturation for thermo-elastic and plastic problems which correspond to the temperature distribution in both cases. Within the steam chamber oil saturation is equal to residual value while outside the steam chamber it is equal to the initial.

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Fig. 1. Final temperature distribution in reservoir for: (a) plastic problem, (b) elastic problem.

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Fig. 2. Final oil saturation in reservoir for: (a) plastic problem, (b) elastic problem.