| 摘要 |
A method and system for recovering fluids from a hydrocarbon-bearing subsurface formation includes a first tubing string run into the well and a second tubing string run within the first tubing string. The annulus between the first and second tubing strings is sealed above a liquid level in the well and at least one fluid passageway is provided between the first and second tubing strings at a location between the liquid level and adjacent the annulus seal. The difference of the liquid head between the inside of the second tubing string opposite the at least one fluid passageway and the outside of the second tubing string (i.e. the first and second tubing string annulus) provides the casing annulus-to-tubing differential pressure that forces gas above the annulus fluid level to pass through the at least one fluid passageway and re-enter the fluid stream in the second tubing string. As less gas or more liquid is produced, the liquid level in the annulus rises and less pressure differential is available to force the gas through the at least one fluid passageway; therefore, less gas will flow into the second tubing string fluid. If more gas or less liquid is produced, the liquid level in the annulus will drop; thereby, creating more pressure differential and more gas will pass into the second tubing string. In this manner, a self regulating system is created that prevents liquid loading of the well.
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