Dynamic Optimization Control of Injection-Production Parameters for Oil Shale Self-Heating In-Situ Conversion

Oil shale self-heating in-situ conversion technology has emerged as a significant development direction due to its environmental friendliness and cost advantages. However, conventional constant injection-production parameters often lead to inefficient compression energy input and formation oxidation losses, limiting further improvement in energy return ratio (ERR) and oil yield. This study establishes a dynamic optimization model for injection-production parameters in oil shale self-heating in-situ extraction and develops a method for dynamically regulating gas injection rate and oxygen content to enhance process economy and feasibility.Results indicate that under the optimal gas injection parameters (adjustment duration: 120 days, decay rate: 1200, final flow rate: 40 m³/day), the steady-state phase in late production reduces compression energy consumption by 90% and CO₂ production by 48%, significantly decreasing cumulative compression energy input and suppressing hydrocarbon oxidation losses. Consequently, the peak ERR reaches 13.87, representing a 132.33% improvement over constant-rate injection, while oil production increases to 47 m³/m, a 66.9% enhancement. Furthermore, synergistic regulation of oxygen content and injection rate reduces compression energy by an additional 16%, elevating the peak ERR to 14.80—a 6.71% further increase—demonstrating technical feasibility for industrial application. These findings and key parameters provide theoretical and technical support for the large-scale implementation of oil shale self-heating in-situ conversion technology.