Abstract:

In order to study the tube effect on defoaming capacity for foaming breaking device, the authors carried out laboratory tests at three different lengths (1 m, 2 m and 8 m). The results show that the length of the tube can affect on defoaming rate; as the tube length decreases, the foam stability and the defoaming rate increase. When the tube length is 1 m and its diameter is 20 cm, the defoaming rate is highest, reaching about 73%. In addition, the gas-liquid ratio (α) also affect on the defoaming rate. When α is 100-200, the defoaming rate was highest. Meanwhile, FLUENT software was used to simulate pressure distribution and foam velocity inside the tube. The simulation results indicate that the foam velocity is independent with the length and diameter of the tube. But the foam pressure is more stable with the decreasing of the tube length, which is beneficial to improve defoaming effect. The VOF model simulation results is in a good agreement with the previous experimental results.

Key words: foam drilling, gap style foam bursting device, storage tube, defoaming rate, VOF model