Experimental Study On Oil - Flooding Characteristics Of Self - Generating Bubble

The study of foam fluid flooding has a history of more than thirty years at home and abroad. The foam flooding has achieved good results in the field application of EOR. But for the study of the autogenetic CO2 foam oil displacement technology, the related reports relatively lesser. This paper is mainly aimed at the questions of long duration of water injection; oil well water production rate is high; the high utilization of the reservoir; but the residual oil saturation is still high in those well field of poor water displacement recovery, we proposed the autogenetic CO2 foam combination oil displacement technique.We carried out the following researches in the lab.(1)Study of autogenetic foam systems:Through a number of lab experiments, we selected good foaming and foam stability of the autogenetic CO2 foam combination flooding system.(2)Performance evaluation of the autogenetic foam system:studying the effects of temperature, pressure, oil content on the foam properties. At the same time we used CWYF-ⅠHTHP reaction apparatus to study the pressure effects on the properties of foam system. We used interfacial tensiometer to study the ability of the autogenetic CO2 foam systems to reduce the interfacial tensions. We also used DV-Ⅲviscometer to study the viscosity of xanthan gum and the long-term stability of the viscosity of the autogenetic foam system. The experimental results show that autogenetic foam systems has good foam performance and viscosity stability in 63℃; But after the temperature of the foam system reaches 70℃, the viscosity can’t keep long-term stability; The interfacial tension experiments showed that after the reaction, the autogenetic foam can reduce the oil-water interfacial tension to below 10-2 with the ability to improve the efficiency of washing oil; viscosity stability experiments showed that the addition of additives JQ can keep the viscosity of the autogenetic CO2 foam systems in the 20MPa·s conditions in a month.(3) The experiment of the physical simulation of oil displacement:Studying the ability to enhance oil recovery of autogenetic foam systems by using the flow experiments of long filling sand tube. The experimental results show that autogenetic foam system can significantly enhance oil recovery.(4) Experimental study of microscopic displacement:Studying oil displacement mechanism of autogenetic foam combination flooding system by the microscopic model. Experimental results shows that mechanism of oil displacement of autogenetic foam system mainly includes:air resistance effect, displacement effect, oil film peeling and the controlling of viscous fingering. (5)Designing schemes for field experiment in the Yangyi fault block of Dagang oil field with the autogenetic foam technology. We analyzed the reservoir conditions and Dynamic production situation of well group in the Yangyi fault block of Dagang oil field. We set the injection method and process parameters with reason.Based on the condition of Dagang oil field, this paper has selected a autogenetic foam system with a good flooding efficiency, it will provides the basis for the field application of autogenetic foam combination flooding system. So this paper has practical application and reference values.