油气储层岩石毛细管自吸研究进展

毛细管自吸是水驱油气藏和裂缝性油气藏开采的重要机理，也是造成致密气藏水相圈闭损害的主要因素。综述分析毛细管自吸的机理认为，储层岩石毛细管自吸包括润湿相饱和度增加和重新分布2个过程。着重研究初始含水饱和度、物性、裂缝、流体性质和岩石表面性质对毛细管自吸速率影响实验的进展，低初始含水饱和度和裂缝的存在促进毛细管自吸过程，储层损害抑制毛细管自吸，流体界面张力改变和岩石润湿修饰可调控岩石毛细管自吸。毛细管自吸在岩芯分析、提高油气采收率、储层损害评价、工作液优选方面已体现出优越性，为注水、聚合物开采提高油气采收率和有效保护油气层提供依据，将成为研究致密油气藏的重要手段。

PROGRESS IN RESEARCH ON SPONTANEOUS CAPILLARY IMBIBITION OF OIL AND GAS RESERVOIR ROCKS

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.