When acid flow along the fracture, the wormhole was developed because some of rock pore or nature fractures are denuded by the acid, thus the filtrateloss of the acid mostly occurs in wormhole.

• 酸液在酸压裂缝内流动时,有少数较大的岩石孔隙或天然裂缝首先受到过量酸液的溶蚀而迅速增长形成蚓孔,使滤失主要在蚓孔内发生。