Feasibility analysis of a droppable igniter for in-situ combustion

The ignition technology is the key of in-situ combustion, which determines the start of in-situ combustion. This paper proposes a droppable solid fuel igniter for in-situ combustion based on the principle of traditional igniter, which aims to design a droppable solid fuel igniter and demonstrate the feasibility of the igniter. The droppable solid fuel igniter can not only guarantee ignition efficiency, but also avoid the pressure fluctuation caused by lifting artificial igniter in recovery process. Firstly, the structure and fuel of the igniter are designed. Industrial solid fuel with hexamethylenetetramine and multipurpose solid fuel with gangue can both meet the ignition requirements of heat and structure. Then, the feasibility of the igniter is studied by oxidation kinetics and thermodynamics formulas. Finally, the applicable conditions of the igniter are obtained by sensitivity analysis. The results show that the reservoir thickness is the key factor if the igniter length is no more than 20 m. This igniter has strong feasibility if the reservoir thickness is less than 12.8 m, but ignition temperature and initial layer temperature should be considered if reservoir thickness is larger than 12.8 m. In theory, the droppable solid fuel igniter can be used in artificial ignition under certain conditions.