Pyrolysis Kinetic Parameters of Omari Oil Shale Using Thermogravimetric Analysis

Oil Shale In Situ Production Using a Novel Flow-Heat Coupling Approach

Oil shale development, a significant global energy concern, involves the pyrolysis of kerogen, a process that can heat and contaminate groundwater with pyrolysis products. To address these challenges, this study introduces the ambient-temperature gas in situ heating (ATGIH) method as an alternative to traditional techniques. The ATGIH method establishes a low-temperature gas barrier to prevent water infiltration into the production zone by placing heating holes between the injection and production wells. The effectiveness of the ATGIH method in mitigating groundwater contamination during oil shale development is demonstrated through thermochemically coupled reservoir simulations. The study further discusses how gas injection enhances the flowability of mobile oil and gas phases into production wells and how controlling the Dykstra-Parsons coefficient, a measure of heterogeneity, can mitigate gravity segregation and aggregate viscous fingering issues. Our results show that well spacing is a critical factor in designing oil shale development, with a larger spacing resulting in higher energy efficiency but lower oil recovery rates. Furthermore, the study reveals that porosity decreases while permeability increases during pyrolysis due to thermal cracking and pore structure changes. It also highlights that heterogeneity-induced issues can be alleviated by increasing the correlation length to make the system more homogeneous. Therefore, the ATGIH method represents a key innovation in oil shale development, offering a solution that mitigates groundwater contamination while improving the energy efficiency.

Thermogravimetric Characteristics and Pyrolysis Kinetics of Nigerian Oil Sands

In the present study, the pyrolysis behavior of Nigerian oil sands was investigated using thermogravimetric analysis. This was done with the aim of deriving kinetic models that can be relevant in the development of the natural resource. The effects of different heating rates (10, 20, and 30 °C/min) on oil sand pyrolysis were studied. The results of the study indicated that three regions comprising low-temperature oxidation, devolatilization, and high-temperature oxidation were obtained at all heating rates. The peak temperatures were observed to rise with an increasing heating rate, a phenomenon described as thermal hysteresis. Mineralogical analysis showed the presence of diffraction peaks corresponding to chlorite, quartz, aragonite, dolomite, calcite, and montmorillonite minerals and the notable absence of expandable clay minerals which are known to pose problems during tailing management and the aqueous bitumen extraction process. The kinetic analysis showed that the activation energy increased with the degree of conversion, with the highest activation energy of 14.682 kJ mol^-1. The Coats-Redfern kinetic model gave the best model fit for oil sand pyrolysis.