Production influencing factors analysis and fracturing parameters optimization of shale oil horizontal wells

Significant productivity breakthroughs have been achieved in key production layers of the shale in Jiyang Depression, notably the lower sub-member of the third member and the upper sub-member of the fourth member of Shahejie Formation. Despite these achievements, the development of these layers is relatively recent, and they exhibit considerable variation in individual well production. The primary factors influencing production remain unclear. Currently, a major focus of research is the comprehensive analysis of the main control factors for high production and the selection of reasonable fracturing parameters for shale oil horizontal wells. To better understand the impact of various factors on horizontal well production, factor correlation and pattern analysis are conducted using field data. Techniques such as gray correlation analysis and principal component analysis are employed to quantify the relationships between the average daily oil production over 90, 180, and 270 days and factors like the volume of fracturing fluid used and sand addition. Subsequently, a shale oil productivity prediction model is constructed, and fracturing parameters are optimized using SHAP（SHapley Additive exPlanations）. The research findings suggest that the volume of fracturing fluid, the amount of sand added, and the number of fracture events are the main engineering parameters affecting production. In contrast, geological parameters such as gray matter content, Total Organic Carbon（TOC）, and porosity significantly influence production as well. Over time, the impact of geological factors on production increases, while the influence of engineering factors diminishes during the later stages of production. Optimization analysis of fracturing parameters determined that a stage length of 40~45 meters, a fracturing fluid volume of 2 700 m³, and a sand addition volume of 180 m³ per stage are the optimal settings. These findings offer new insights for development determination and fracturing design in shale oil horizontal wells.