In the deep hole of gas pumping

double plugs buoyancy method is used to install mine gas pipe. Because velocity of exhausting the pressure air in two plugs is difficulty controlled and there is large pressure difference between internal and external gas pipe

sometimes the pipe is collapsed and mud sprays out the pipe

at last the sinking pipe is failure. Based on the above reasons

the buoyancy method of sinking pipe is put forward filling of the autoclaved aerated concrete blocks used for floating pipes. In the experiment

the autoclaved aerated concrete blocks are put in the pressure tank

and then confining pressure strength of the AAC is 6 MPa which is associated with 500 m depth under the mud and the volume change rate of the AAC

which should not be considered in the application

is also measured to be 1.68% while the density of the AAC is 660 kg/m

3

. Field application shows that the pipe filling of autoclaved aerated concrete blocks reduce the load of the rig. For the pressure between internal and external gas pipe is equal

what the collapse of the pipe is completely avoided and that pipe wall becomes thinner brings obvious economic benefit.