Capillary Number Under Different Conditions Of Ternary Complex Experimental Flooding Flooding Effects

With the development of the world's economy, the status of crude oil resources has become more and more important, the reserves and production of petroleum have been the most important factors that restrict the development of a country's economy, so finding new techniques has become a significant problem to all petroleum engineers all over the world. Our country has a large amount of petroleum reserves, but after the primary and secondary recovery, most reservoirs entered a high water cut period. This brings an insistent demand to find a new effective way in producing oil which we now call "tertiary recover technology ". After years of researches, chemical flooding, especially polymer flooding, has been accepted gradually by most reservoir engineers in our country, and developed into an effective tertiary recovery technology which adapts to our own situation.Through physical simulations in laboratory and tentative experiments in oilfield, reservoir engineers gradually comprehend the mechanism that polymer flooding can increase the recovery ratio. Most people think, the mechanism of polymer flooding is to reduce the mobility ratio, restrain the rush flow of the injecting water then increase the areal sweep efficiency, thus the residual oil saturation after water flooding and polymer flooding should be equal. But recent researches indicate that if we make a flooding experiment with Viscoelastic fluid and viscous fluid under the same condition, the residual oil saturation of the former is considerably lower than the latter, this illustrates that polymer solution with Viscoelasticity can not only increase the macroscopic sweep efficiency but also largely increase the microscopic displacement efficiency.Based on the academic experiences of the former scientists, a series of experiment was varied out with different Viscoelastic solution system such as polymer solution system, polymer-surfactant binary system and polymer-surfactant-alkali ternary system. The result indicates that, the flushing efficiency increases with the capillary number, the flushing efficiency of the Viscoelastic solution system (HPAM system ) is considerably higher than the Xanthan system and the glycerin system. This can give a firmer support to the Viscoelastic theory, which considers that the Viscoelasticity of polymer solution can greatly increase the recovery ratio of petroleum in stratum.