Crown-drilling pumping sand:
Use Case drilling type pumping sand pumping sand drilling type is mainly applied to a thick layer of mud conditions, first penetrated by the drill mud layer, and then extract the sand and mud layers below piped to shore, which is mainly aimed at the general mechanical suction dredgers and sand the site does not work and developed a works: first, the drill equipment work fully erect, and start driving slowly rotating the drill bit after decentralization, devolution process pumps and pumping sand pump to start playing with the drilling, until the decentralization to begin Chousha sand. To be on reducing the amount of sand, then the appropriate drilling depth adjustment decentralization.