Rheological Properties Of High Temperature And High Pressure Foam

For the sake of matching foam fluid frilling technology, international developed country has developed a series of foam fluid process technology, which run through each process of drilling, consummate well, increase output, exploitive and dynamic adjust. We can anticipate the foam technique will be the very broad applied foreground in our country; however, a common and important foundation research in the above-mentioned process is measuring the rheological properties of foam under the high temperature and high pressure conditions.So through a lot of experiments and oil field investigate we designed a set of complete testing method and equipments about rheological properties of foam under high temperature and high pressure conditions and then did a lot of experiment-study. The study conclusion consists of 5 parts:1. Foam rheology should be characterized by the Power law model in the scope of our experiments. The equation may be expressed as:where r =shear stressr =shear ratek consistency index n =flow behavior index;2. As foam quality increases, the foam increases in apparent viscosity;3. The foam apparent viscosity decreases with the increasing of shear rate;4. Temperature has significant effect on rheological properties of foam. The foam apparent viscosity unsteadily decreases with the increasing of temperature. With a certain foam quality and pressure, the flow behavior index will increase while consistency index decrease as increasing in temperature;5. The effect on foam rheological properties of the pressure is very complex, which may indirectly affected the rheological properties through foam quality, density and so on. As pressure increases, the average size of bubbles in the foam decreases and the fluid becomes more denser; Even pressure changes a little, the volume of gas changes greatly too so that there are some changes in foam quality ,density and so on. The apparent viscosity will increase with the increase of pressure, but when shear rate up to some range the effect extent will decline.