关键词: 油气层, 毛管力, 自吸, 润湿性, 储层损害, 采收率

Abstract: Spontaneous capillary imbibition is main recovery mechanism in water driving especially in fractured oil and gas reservoirs，also，is the dominate factor causing water phase trapping damage in tight gas reservoirs.The authors of this paper discuss the mechanisms of spontaneous imbibition in detail and conclude that increasing of the wetting phase saturation and the redistribution of wetting phase are main factors causing spontaneous imbibition.The paper focuses on the progresses in experimental research and scale methods on effects of initial water saturation，physical property，facture parameters，fluid properties and rock interface on spontaneous imbibition rate.Low initial water saturation and fracture in reservoirs can accelerate water spontaneous imbibition，while formation damage can restrain water spontaneous imbibition into reservoirs.Spontaneous imbibition can be controlled by the change of interfacial tension alteration and/or rock surface modification.The advantages of spontaneous imbibition have been showed in application of core analysis，enhancing oil/gas recovery，formation damage evaluation and optimizing working fluid.Spontaneous imbibition provides important data for water or polymer injection to increase oil/gas recovery，and will be an important tool to research on tight gas reservoirs.

Key words: oil/gas reservoir, capillary force, spontaneous imbibition, wettability, formation damage, recovery