this research, thermal characterization and kinetics of Karakus crude oil
in the presence of limestone matrix is investigated. Thermogravimetry (TG/DTG)
is used to characterize the crude oil in the temperature range of 20-900C,
at 10C min -1 heating rate using air
flow rate of 20 mL min -1. In combustion
with air, three distinct reaction regions were identified known as low temperature
oxidation (LTO), fuel deposition (FD) and high temperature oxidation (HTO).
Five different kinetic methods used to analyze the TG/DTG data to identify
reaction parameters as activation energy and Arrhenius constant. On the other
hand different f(α) models from literature
were also applied to make comparison. It was observed that high temperature
oxidation temperature (HTO) activation energy of Karakus crude oil is varied
between 54.1 and 86.1 kJ mol -1, while low
temperature oxidation temperature (LTO) is varied between 6.9 and 8.9 kJ mol -1.
High pressure thermogravimetric analysis (HPTG) was used in order to study the oxidation of crude oil in a porous medium under
pressurised conditions for simulation of in-situ combustion during oil recovery. Three distinct reaction regions were observed
from the HPTG curves in an oxidising environment subjected to a constant heating rate. These were low temperature oxidation,
fuel deposition and high temperature oxidation. The method of Coats and Redfern was used to obtain kinetic parameters and
the results are discussed.
Authors:M. Kök, G. Pokol, C. Keskin, J. Madarász, and S. Bagci
In this study the combustion characteristics of crude oils (Karakuę and Beykan) in the presence of a limestone matrix were
determined using the thermogravimetry (TG/DTG). Experiments were performed at a heating rate of 10C min-1, whereas the air flow rate was kept constant at 10 L h-1 in the temperature range of 20-900C. In combustion with air, three distinct reaction regions were identified in all crude
oil/limestone mixtures studied known as low temperature oxidation (LTO), fuel deposition (FD) and high temperature oxidation
(HTO). The individual activation energies for each reaction region may be attributed to different reaction mechanisms, but
they do not give any indication of the contribution of each region to the overall reactivity of the crude oils. Depending
on the characteristics, the mean activation energy of samples varied between 50.3 and 55.8 kJ mol-1.
In this research, the effect of different lithology (limestone and sandstone) on the combustion of light crude oils was investigated
using thermal analysis techniques. Three distinct reaction regions were identified in all of the crude oil+limestone and sandstone
mixtures, known as low temperature oxidation (LTO), fuel deposition (FD) and high temperature oxidation (HTO), respectively.
Kinetic analysis of the crude oil+limestone and sandstone mixtures was performed using Coats and Redfern method and the results
In this research, non-isothermal kinetics and feasibility study of medium grade crude oil is studied in the presence of a
limestone matrix. Experiments were performed at a heating rate of 10°C min−1, whereas the air flow rate was kept constant at 50 mL min−1 in the temperature range of 20 to 600°C (DSC) and 20 to 900°C (TG). In combustion with air, three distinct reaction regions
were identified in all crude oil/limestone mixtures, known as low temperature oxidation (LTO), fuel deposition (FD) and high
temperature oxidation (HTO). The activation energy values were in the order of 5–9 kJ mol−1 in LTO region and 189–229 kJ mol−1 in HTO region. It was concluded that the medium grade crude oil field was not feasible for a self-sustained combustion process.
During the process of the offshore development, seabed pipeline is an important infrastructural facility with huge investment, and its safety should be ensured. The seabed pipeline may stop transporting the crudeoil during operation, and the
In order to fit in with the changing of the crudeoil market, the projects of increasing the storage of the crudeoil were executed in the oil field. There were a lot of large crudeoil tanks in the oil field, as
This paper investigates the minimum oil content necessary for self-sustained combustion, which is introduced as a criterion
for the selection of suitable reservoirs for in-situ combustion processes. Differential scanning calorimetry was used to determine
the heat values of oil-limestone mixtures. The minimum temperature required for the total consumption of the fuel was obtained
by thermogravimetry (TG/DTG). The minimum amount of oil necessary to sustain combustion was calculated from these two parameters
and compared with the oil content of the reservoir. Reservoirs with an oil content greater than or equal to this minimum value
were considered feasible. It was seen that the fields examined are generally not suitable for in-situ combustion processes.