Heliyon (Oct 2024)
Correlation between comprehensive evaluation method for fracture complexity in tight reservoirs post-fracturing and production capacity
Abstract
The complexity of post-fracturing fractures in tight reservoirs is critical for evaluating fracturing effectiveness and is also a significant factor influencing well productivity. Currently, some scholars have utilized an improved G function to study the complexity of hydraulic fractures after fracturing. However, in certain specific construction curves, the characteristics and values of the G function alone are insufficient for comprehensive interpretation. To conduct a more thorough analysis of fracture complexity, this study introduces net pressure and liquid efficiency—parameters related to fracture complexity—based on the G function, and performs statistical analysis. Since the G function curve morphology is image data, it is not suitable for quantitative analysis. Therefore, digital calibration was conducted based on its corresponding morphological features to render it amenable to data analysis. Using Principal Component Analysis (PCA), a comprehensive fracture complexity coefficient was proposed, which considers four parameters: the digital calibration of the G function curve, G function characteristic values, net pressure, and liquid efficiency. The relationship between this coefficient and productivity was examined through Pearson and Spearman correlation analyses, utilizing post-fracturing production data from 26 wells in the Dabei block for validation. The results indicate a significant positive correlation between the comprehensive fracture complexity coefficient and productivity, with a high degree of correlation. This method not only addresses the shortcomings in interpreting certain specific construction curves but also provides a more comprehensive quantitative characterization of fracture complexity. Preliminary validation confirms the applicability of the method, offering valuable insights for evaluating post-fracturing effectiveness.
