页岩油水平井产量影响因素分析及压裂参数优化决策

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

济阳坳陷页岩在沙三下亚段和沙四上亚段等主要产层获得重大突破,但开发时间短,存在单井产量差异较大,产量主控因素尚不明确的问题,深入分析页岩油水平井高产主控因素、优化确定合理压裂工艺参数仍是目前研究的重点。为明确各因素对水平井产量的影响,基于矿场实际数据开展因素关联性分析和规律挖掘。利用灰色关联分析方法及主成分分析方法定量计算页岩油水平井生产90 d、180 d和270 d的平均日产油量与压裂液用量、加砂量等影响因素之间的相关性,并在此基础上建立页岩油产能预测模型,结合SHAP算法对压裂参数进行优化分析。结果表明:压裂液用量、加砂量和破裂事件数是影响产量的主要工程参数,灰质含量、总有机碳含量和页岩孔隙性是影响产量的主要地质参数;随着生产时间的延长,地质因素对产量的影响逐渐增强,工程因素对产量的影响逐渐减弱;压裂参数优化分析确定了40~45 m压裂段长,2700 m3单段压裂液用量,180 m3单段加砂量为最佳压裂施工参数,为页岩油水平井的开发决策和压裂设计提供了新的技术思路。

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 2700 m³,and a sand addition volume of 180 m³per stage are the optimal settings.These findings offer new insights for development determination and fracturing design in shale oil horizontal wells.