Lost Circulation and Countermeasures in Geological and Mining Exploration Drilling

By analyzing the geological leakage conditions of the drilling process,we propose a hydration expansion composite system and evaluate the ability of expansion,plugging and bridge sealing.The results show that plugging material PAR has highly absorbent properties and can be expanded to several times of the original size,and the quick process helps to form the rapid plugging.The system is composed of the material PAR,paddy and sawn wood and has a very strong plugging rate of more than 70%;the experiment of complex system in plugging pressure measuring devices shows that the composite system cannot only block the formation but also bear a certain degree of pressure.The composite system canfully meet the needs of the Yunnan lead mine drilling.