New Method for Evaluating the Development Effectiveness of Waterflooded Reservoirs

Waterflooding is a primary technique in oilfield development. However, most oilfields have now entered the (ultra-)high water-cut stage, making the improvement of waterflooding performance in high water-cut oilfields a globally significant research topic. It is particularly crucial to scientifically establish a comprehensive evaluation model, methodology, and technical framework for oilfield development performance, identify key breakthroughs for enhancing recovery efficiency, and propose adjustment measures to unlock reservoir potential. This study employs systems analysis and data mining techniques to evaluate various parameters of waterflooded reservoirs through four key dimensions: reservoir characteristics, engineering operations, wellsite management, and production economics. The research identifies mutually independent yet critical development indicators through a combined subjective-objective approach, utilizing multiple data mining algorithms to mitigate human bias and the inaccuracies inherent in single-algorithm evaluations. The hierarchical clustering method was applied to screen development indicators closely associated with waterflooding performance and determine their weighting coefficients. Theoretical principles, statistical patterns, and technical requirements were transformed into quantitative feature descriptors to establish evaluation criteria for each parameter. By calculating composite scores for reservoirs, the study provides a systematic approach to assess waterflooding effectiveness. The research comprehensively considers all factors influencing oilfield development performance, analyzes the intrinsic relationships among evaluation indicators, and reveals the fundamental mechanisms governing development effectiveness. These findings provide essential insights for optimizing oilfield development strategies.