Development and experiment of casting and fishing high pressure gas-lift valve in deep well

The deep formation fluid lifting should not only let the oil to the wellhead but also ensure the liquid from the wellhead to gathering platform or remote ground processing. Because the subsea pipeline is long, the liquid flow security must be guaranteed. So the deep mining requires higher gas injection pressure. The gas into the tubing arriving at wellhead still has certain pressure which can ensure the completion fluid flow. The filling nitrogen pressure of conventional gas-lift valve is limited so suppress the depth. At the same time, the pressure loss of traditional gas-lift valve gas is large, critical velocity range is relatively narrow, which is not stable for lifting. In order to solve this problem author develop a high pressure gas-lift valve, The test show that the inflation pressure and opening pressure of gas-lift valve significantly increased. In the meanwhile, the critical velocity range is improved, provide security for deep water lifting.