Preparation Of Colloidal Gas Aphron And Its Properties Study On Oil Displacement

Colloidal Gas Aphron(CGA)has a great potential in foam flooding, because of its special structure and nature. There are some problems in traditional foam-drive process such as high injection pressure, asphaltene and other organic matter depositing in the drive hole, so it is necessary to develop a new driving foam. At first, we focused on adding modifier to CGA and selecting foam system of CGA in this study, optimization analysis of conditions to prepare CGA was then carried on. Merey16 Crude oil and Feng-cheng simulated oil were taken as base oil to study on CGA foam flooding, we measured the interfacial tension of different CGA system under optimal concentrations, discussed structure and stability of CGA with the help of optical microscopy, injection pressure, recovery rate and the changes in asphaltene were also measured.In this experiment, we did research on filtering single and mixed CGA system that had been added modifier and optimization analysis of characteristics under modifier and blank system, mainly seeing about the impact of frother concentration, foam stabilizing agent concentration, temperature, stirring rate, stirring time, salinity, and crude oil. The results showed that under the conditions: adding GXJ-II 0.1g/L, 3min stirring time and 8000rpm stirring rate, the output and half-life of the mixture of SDS(1g/L)and OP-10(3g/L)was 590mL/100mL and 420s, the output and half-life of the mixture of SDS(2g/L) and Petroleum Sulfonate(3g/L)was 580mL/100mL and 265s under the same conditions; CGA showed a shape with a transparent multi-layer spherical under the optical microscope.The study that the foam fluid enhancing oil recovery experimentation after preparation of colloidal gas aphron was evaluated, showed as flooding Merey16 crude oil, injection pressure of modified CGA was reduced by about 20%～40% than the blank experiment and recovery ratio is increased from water flooding 41.6%, blank flooding 56.6% to 62.8%; in the simulation of core flooding the Merey16 oil with water flooding, blank CGA flooding, modified CGA, the injection pressure was significantly lower, modified CGA on the base of water flooding and blank flooding could make the recovery ratio further increase 20.9%, asphaltene content of crude oil were increased 26.8% and 34.9% than water flooding and blank flooding, the interfacial tension was also reduced from 3.20mN·m^-1 to 2.78mN·m^-1. As flooding Feng-cheng simulated oil, the injection pressure was reduced obviously and recovery ratio was further increased 11.1%. Modified CGA foam-drive fluid which we worked out had important theoretical consequences and industrial application prospect.