High-pressure air injection laboratory-scale numerical models of oxidation experiments for Kirsanovskoye oil field

Abstract

High-Pressure Air Injection (HPAI) as an enhanced oil recovery (EOR) method has a high potential and has already been effectively applied for carbonate reservoirs development. The target object of the current research is a Kirsanovskoe oil field confined to the North Kinelsky oil and gas region. Kirsanovskoye field is a carbonate reservoir with an average depth in the range of 1300–1350 m, average porosity of 11.5%, and average permeability of 70.6 mD.The HPAI process, which includes intensive oxidation and combustion reactions, phase transitions of components and change in the composition and properties of coexisting phases, is not fully explored yet. Its complexity and lack of reliable chemical and kinetic models both for light and heavy oils cause several limiting factors for the construction of a field numerical model with the high predicting level in the respect to the HPAI as the EOR method.The presented work is devoted to the construction and validation of laboratory-scale numerical models of oxidation experiments to provide proper HPAI kinetic model for oxidation and combustion reactions for the Kirsanovskoye oil field. For these purposes, high-pressure ramped temperature oxidation (HPRTO) and subsequent Medium pressure combustion tube (MPCT) experiments were conducted and analyzed. HPRTO test is used for the determination of the reaction kinetics together with such characteristics as a function of temperature, O2 uptake, CO2 generation, oxidation front velocity, peak temperatures, residual coke, and amount of burned and recovered oil. MPCT provides information on stoichiometry for the high-temperature process and optimal airflow rate. A significant part of the research is dedicated to the construction of 3D numerical models (multilayer design, proper heater regime, etc.) of HPRTO and MPCT experiments to avoid constructional uncertainties and their further validation against the experimental data. To describe the chemical behavior of hydrocarbons during the HPAI process we use the reaction scheme which includes polymerization of Malthenes and Asphaltenes in low-temperature oxidation region, thermal cracking and coke combustion in the high-temperature oxidation region.