Screening In Situ Combustion Applicability for a Heavy Oil Candidate Reservoir with an Accelerating Rate Calorimeter

Abstract

Air injection has immense potential for hydrocarbon recovery from various reservoirs. One of the screening techniques which can be applied to evaluate a candidate oil for the air injection process is the accelerating rate calorimeter (ARC). The unique feature of this instrument is that it can provide adiabatic conditions and handle experiments at high pressures. This paper reviews four tests performed in closed and flowing ARCs to fingerprint and observe the thermal behavior of a crude oil. The crude oil used for this study is characterized as a 19.3°API and viscosity of 710 mPa.s at 21°C. The oxidation experiments were performed under two scenarios of oil-only and oil in the presence of native carbonate core. Initial starting conditions of each test were at a temperature of 23°C and a reservoir pressure of 13.8 MPa. Flowing ARC experiments showed that Low-Temperature Oxidation occurs at a temperature of about 150°C, whereas ignition occurs at about 350°C when High-Temperature Oxidation region was dominant. However, when using the closed ARC, the thermal behavior of the studied oil appeared to have different temperature characteristics, and the onset of the maximum self-heat rate occurred at temperature of 288°C. The effect of the vapor phase combustion as well as the calculation of kinetic parameters are also discussed in this work.