| 摘要 |
A pipe in pipe piston thrust system comprises a plurality of piston assemblies configured to sealingly engage a wellbore, a pump configured to transfer a fluid into the wellbore, and a by-pass disposed between a plurality of annuli formed by the plurality of piston assemblies. The by-pass allows for selective communication of the fluid between the plurality of annuli. 1104 | || || l|| l| 120-4 |
