Abstract & Overview
The success rate of controlling lost circulation may be low if the particle size distribution,concentration and volume of LCM mud pumped are only decided by the loss rate. A progressive method can be used in curing lost circulation;using fine particles at low concentration to medium or coarse particles at moderate or high concentration,and pumping while mixing the LCM mud. If the width or length of fractures taken mud is not quite defined,this method may provide a way of stopping lost circulation. This method has been applied in 6 wells for 7 times,and is 100% successful.