ABSTRACT
The stability and breaking of nonaqueous foams is a subject of great importance to the oil industry, as such foams occur, for example, in the production and refining of crude oil, and during the use cycle of many products such as lubricants. This chapter discusses the specific problems encountered with foams in the oil industry. When crude oil is produced, it is forced from the reservoir by pressure up the production tubing to the surface. There are two extreme structures which foams can assume; these are the classical polyhedral structure and the round-bubbled or gas dispersion structure. The stability of nonaqueous foams has been shown by numerous authors to be related to the following physicochemical properties: bulk rheological properties of the foaming liquid, the nature of the filler gas, the composition of the foaming system, and the shear and dilatational properties of the gas-liquid interface.
