Oilfield drilling fluid is divided into three categories according to the dispersing medium: water-based drilling fluid, oil-based drilling fluid and gas-based drilling fluid. Oil and gas formations have certain requirements for drilling fluids, which need to be matched with the rocks of the formation, and the components of the drilling fluids do not have precipitation reactions with the formation fluids to prevent scaling and other damages, and they do not have emulsification reactions with the formation fluids, and the surface tension of the drilling fluids should not be too high. In order to prevent damage to the oil and gas formation caused by solid particle plugging, the solid phase content should be reduced as much as possible.

There are many reasons for oilfield drilling fluid foaming, in the drilling process, the gas in the formation will invade the drilling fluid, and these gases will not be able to escape in time, leading to foaming of the drilling fluid; oilfield drilling fluid contains many surface-active substances, which have foaming characteristics, leading to foam generation; the decomposition of the treatment additives added in the process of drilling will produce gas, which will generate gas bubbles, and due to the mixing operation of the equipment, which results in a large amount of air being The air will be swept into the oilfield drilling fluid, which will lead to foam generation.