机械消泡法试验研究

Experimental Research of Mechanical Defoaming Method

研究了机械消泡法中喷射压力、喷嘴直径、气液比和喷嘴与挡板间距离4个参数与消泡率关系。结果表明:喷嘴内外压差越大,泡沫更易膨胀破裂。消泡率随喷射压力上升而增加,推荐喷射压力为0.3～0.5MPa;相同条件下消泡率随喷嘴直径增加而降低,但是当喷嘴直径>5mm时,消泡率随喷嘴直径增大而降低的速度明显趋缓,喷嘴直径宜取5～6mm;消泡率随气液比的增加而增加,在满足钻井工艺要求的前提下,可以选择含气量较高的泡沫;喷嘴至挡板间距离与消泡率基本无关,但挡板的作用仍然不容忽视。研究结果为实现机械与化学联合消泡提供技术支持。

Through the developed foam circulation device, the influence of iniection pressure, nozzle size, gas liquid ratio and distance between nozzle, and the baffle on defoaming rate were studied. The results show that the greater the internal and external pressure difference in nozzle, the easier the foam swelling and rupturing. Therefore, the defoaming rate increases with the increase of in- jection pressure and the injection pressure value about 0.3-0.5 MPa is suitable for this device. In the same condition, the defoaming rate decreases with the increase of nozzle size and levels off af- ter the size reaches to 5 mm,so the nozzle size about 5-6 mm is recommended. Because of the similar change rule between defoaming rate and gas liquid ratio, the higher gas content is the best choice if the foam quality meets the drilling process requirement. Although the distance between nozzle and baffle has no influence on the defoaming rate,the role of baffle can＇t be ignored. The foundation for the design of the mechanical defoaming device is established and the technical sup- port to realize mechanical and chemical combination defoaming is provided.