The technology of pig lift is using the dual string of U type(one to input and another to production) to product .

Considering the problem that different diameter combined tubing are adopted and conventional plunger lifting no longer applies in deep well,this paper presents a kind of new relaying type plunger gas-lift equipment applied to upper large down junior combined tubing.

Study on plunger lift technique with gas produced from in-situ wells were carried out with field experiments conducted, which proved that.

In this paper, a dynamic model for plunger lift operations was established, the dynamic.

The methods for the plunger liftsystem analysis and well completion design are introduced, and a statement is made on the selection of the accessory tools and the optimization of the string as well as the surface equipment matching.

The Research of Continuous Production Plunger Airlift without Well off Technique;

According to the condition and geological factors of the well in Changqing gas field and on the basis of the research on spume gas recovery, we conduct the plunger airlift draining gas recovery research, in order to cope with the hydrops in the bottom of well.