为研究页岩储层对压裂液的自发渗吸机理，以四川盆地龙马溪组海相页岩和鄂尔多斯盆地延长组陆相页岩为研究对象，以实际压裂液为渗吸流体，采用自发渗吸测试系统，结合矿物组分和微观孔隙表征方法，重点研究海相和陆相页岩对压裂液的自发渗吸特征及其控制机理。结果表明：两组页岩自发渗吸曲线随渗吸时间增加均呈先迅速增大后缓慢减小趋势，其渗吸量减小主要源于可溶性矿物溶解导致的页岩重量减少；两组页岩总有机碳（total organic carbon, TOC）和石英含量与最大渗吸量具有负相关性，而黏土矿物、碳酸盐和孔体积与最大渗吸量具有正相关性；延长组页岩黏土矿物含量虽高于龙马溪组页岩，但其最大渗吸量却相对较低，这可能源于龙马溪组页岩具有更发育的孔隙结构；页岩亲水性矿物的吸附作用和微观孔隙的毛细作用是压裂液自发渗吸的主要驱动力，且微观孔隙的影响程度要强于亲水性矿物。针对页岩气井压裂液返排问题，可通过调整压裂液化学成分，并结合压裂液自发渗吸测试结果，提出更优的压裂液配比方案，以满足实际工程需要。研究结果可为页岩气高效开发提供理论参考。

To investigate the spontaneous imbibition mechanism of shale reservoirs to fracturing fluid, the marine shale of Longmaxi Formation in Sichuan Basin and the continental shale of Yanchang Formation in Ordos Basin were taken as the research object, and the actual fracturing fluid was taken as the imbibition fluid. The spontaneous imbibition characteristics and control mechanism of marine and continental shales on fracturing fluid were studied by the spontaneous imbibition test system and the characterization methods of mineral composition and microscopic pore. The results show that the spontaneous imbibition curves of the two groups of shale increase rapidly and then decrease slowly with the increase of imbibition time, and the decrease of imbibition is mainly due to the decrease of shale weight caused by the dissolution of soluble minerals. TOC (total organic carbon) and quartz content of the two groups of shale exhibit a negative correlation with the maximum imbibition, while clay minerals, carbonate and pore volume exhibit a positive correlation with the maximum imbibition. Although the clay mineral content of Yanchang Formation shale is higher than that of Longmaxi Formation shale, its maximum imbibition is relatively low, which may be due to the more developed pore structure of Longmaxi Formation shale. The adsorption of hydrophilic minerals in shale and the capillary action of microscopic pores are the main driving forces for the spontaneous imbibition of fracturing fluid, and the influence of microscopic pores is stronger than that of hydrophilic minerals. For the flowback problem of fracturing fluid in shale gas wells, a better fracturing fluid ratio scheme can be proposed by adjusting the chemical composition of fracturing fluid and combining the spontaneous imbibition test results of fracturing fluid to meet the actual engineering needs. The research results can provide theoretical references for efficient development of shale gas.