Study On Oxidation And Heat Release Process Of Air Injection Technology For Oilfields

Air injection technology has broad development prospects in oilfields.This technology,which holds obvious technological advantages,can be applied to both thin oil and heavy oil reservoirs.Oxidation and exothermic reaction in an air injection process is an important essence and mechanism of the technology.Therefore,it is essential for better application of this technology to get a better knowledge of the oxidation and exothermic reaction.In this paper,we explore the stage of the oxidation and exothermic reaction and further identify the concept of low-temperature oxidation.In this paper,the testing principle,applicability,advantages and disadvantages of common thermal analysis instruments are analyzed firstly.The results find that it is not feasible to use a single instrument to perform a complete description of the low-temperature oxidation process.Therefore,PDSC and ARC are chosen to use in further studies.The oxidation and exothermic reaction experiments are conducted on the two instruments respectively,and their deficiencies are found.On the basis,the experiment for interval partition of the oxidation and exothermic reaction is carried out combined with the basic research of oxidation thermodynamics.Two kinetic curves are obtained and the effects of related errors are analyzed.The research shows that The faster the heating rates is,the greater the maximum heat flow value of LTO and HTO peak value is.The heat flow-temperature curve is more tend to shift to the high temperature stage,and the heat release rate in the low temperature oxidation stage accounts for a reduction in the percentage of heat released in the whole section.The mathematical models of PDSC and ARC are established by oxidation kinetics analytic procedure,which can be used to represent the relationship between lnk and 1/T,and to establish the same dynamic coordinates.Mathematical models for PDSC and ARC were established using oxidation kinetic analysis method.For the same oil samples,the activation energies measured by PDSC and ARC are 141.64kJ/mol and 150.11kJ/mol respectively,which are very close to each other.In the dynamic coordinates,there is a high similarity between the two curves,showing that the two reaction processes is in the very similar reactive state.