During drilling through the SK500m exploratory formation in iran,the PHP-CMC gel low-solid mud is used to drill the overburden against loss circulation,clean water and the double-tube swivel type diamond drilling tool used to drill the test interval and kill the water flow,and then the PHP-CMC gel non-solid fluid used for hole-wall protection to the final depth with the pump pressure grouting method to stabilize the hole walls. This results in better solutions to deviation,blockage,loss circulation and water ingression.