Adaptability Analysis of Multi-stage Temporary Plugging and Fracturing Technology Based on Fuzzy Comprehensive Evaluation Method: A Case Study of Chang-6 Reservoir in Suijing Oil Field

The Suijing Oil Field is characterized by its typical extra-low and ultra-low permeability reservoirs. In order to maximize reservoir producing degree and the production of single well, while also managing the increase in water content, a novel approach of plugging old seams and compressing new ones has been implemented. This involves the use of interlayer and intralayer multi-stage temporary plugging and fracturing technology. To assess the effectiveness of multi-stage temporary plugging and fracturing construction and its process adaptability, an evaluation matrix was developed. This matrix evaluated the temporary plugging and fracturing effect based on 9 parameters: formation pressure, sand amount, displacement, sand ratio, oil well production, temporary plugging agent dosage, fracturing pressure, relative change rate of daily oil production, and relative change rate of water content. Fuzzy comprehensive evaluation was conducted for the oil wells constructed in the Triassic Chang-6 reservoir of the Suijing Oil Field formation. The study determined the adaptability effectiveness of the multi-stage temporary plugging and fracturing process system. Based on the principle of membership degree determination, the effectiveness of multi-stage temporary plugging and fracturing in the Suijing Oil Field can be classified into 5 grades: ‘excellent, good, moderate, poor, and bad.’ These results offer valuable insights for optimizing parameters in the subsequent implementation of ‘multi-stage temporary plugging and fracturing’ in similar reservoirs.