Abstract
Heavy oil reservoirs are characterized by high oil viscosity, low mobility, and limited efficiency of conventional production methods. In Kazakhstan, a significant portion of heavy oil production is concentrated in shallow, low-temperature reservoirs where cyclic steam stimulation (CSS) is the dominant enhanced oil recovery method. However, published studies indicate that the effectiveness of steam-based technologies is constrained by high energy consumption, heat losses, and declining performance at mature stages of field development. This paper presents a review of thermo-chemical and thermo-gas-chemical stimulation (TGCS) methods based on in-situ generation of heat and gas through exothermic reactions. Reservoir conditions of major heavy oil fields in Kazakhstan are analyzed using published data from the Kenbai (East Moldabek block) and Karazhanbas fields. Quantitative results reported in experimental and analytical studies on thermochemical fluids, composite thermochemical flooding, and aluminum-based heatgenerating systems are reviewed. The analysis shows that TGCS can provide localized thermal and pressure effects and may serve as an energy-efficient complementary technology to conventional steam-based methods in shallow heavy oil reservoirs.