连续投砂法在钻探工作中并不是一种新的方法，差不多与开始采用铁砂钻进的同时，就采用了小份量定期向孔内连续补投铁砂的方法。在此基础上也设计出了一系列的投砂器，但这种方法必竟不是真正的连续不断的向孔内供给铁砂，而有一定的时间间隔，一旦供砂时间掌握不好，即影响效率或造成岩心堵塞，结果逐渐被一次投砂法代替，而放弃了这种钻进方法。 The continuous sand casting method is not a new method in the drilling work. Almost simultaneously with the beginning of iron sand drilling, a small amount of iron sand was continuously added to the hole. On this basis, a series of sand throwers have also been designed. However, this method is not a true continuous supply of iron sand to the hole, but there is a certain time interval. Once the sand supply time is not mastered, it will affect the efficiency. Or it caused the blockage of the core. The result was gradually replaced by a sand casting method and the drilling method was abandoned.