抄録
To address the micro-scale effects triggered by the complex pore-throat structures of tight oil reservoirs and the ambiguous fluid seepage mechanisms resulting from the coexistence of multiple media after volume fracturing, this study aims to construct a production prediction model capable of accurately characterizing the dynamic evolution of multi-scale media. Based on the trilinear flow theory framework, a mathematical productivity prediction model for fractured horizontal wells in tight oil reservoirs was established by integrating the matrix threshold pressure gradient, high-velocity non-linear flow (Forchheimer flow regime) in primary hydraulic fractures, and multi-scale dynamic stress sensitivity effects across the matrix, secondary fractures, and primary fractures. The model was solved efficiently using a non-linear iterative coupling algorithm. Validation against field production data from the study area demonstrates a high degree of consistency, confirming the reliability of the model in evaluating production dynamics within complex fracture networks. Sensitivity analysis reveals a differential effect of stress sensitivity across multi-scale media: the stress sensitivity of secondary fractures exerts a decisive influence on productivity, serving as the core physical bottleneck constraining long-term stable production in tight oil. Additionally, the high-velocity non-linear effects in primary hydraulic fractures significantly inhibit the initial production rate, while the matrix threshold pressure gradient has a relatively limited marginal impact on overall yield under well-developed fracture network conditions. These findings quantitatively elucidate the contribution weights of the dynamic evolution of physical properties across different scales of media, providing essential theoretical support and a decision-making basis for the optimization of fracturing treatments and differentiated proppant placement designs in tight oil reservoirs.
