Gas lift system having expandable velocity string
AssigneeWeatherford Technology Holdings, LLC
InventorsWilliam C. Lane, Deborah L. Banta
Life of this patent
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Abstract
A velocity string deploys in production tubing of a gas well (or a gassy oil well) to help lift fluid toward the surface. The velocity string reduces flow area in the production tubing so that a critical flow velocity can be reached to lift liquid. Overtime, the reservoir pressure and resulting gas flow may decrease such that less liquid is produced toward the surface. At such a stage, operators then expand the velocity string to further decrease the flow area in the production tubing, which can produce the needed critical flow velocity to allow produced liquid to be lifted toward the surface.
Claims39
A method of lifting fluid produced from a gaseous well toward the surface, the method comprising:
- reducing a flow area of the gaseous well by deploying a velocity string in production tubing of the gaseous well;
- lifting the produced fluid through the reduced flow area at least partially toward the surface;
- decreasing the reduced flow area of the gaseous well by adjusting a cross-sectional dimension of the velocity string while deployed in the production tubing;
- and
- lifting the produced fluid in the decreased flow area at least partially toward the surface.
A fluid lift system for a gaseous well, the system comprising:
- a velocity string deploying in production tubing of the gaseous well and having a first state with a first cross-sectional dimension,
- the first cross-sectional dimension reducing a flow area of the production tubing and configured to produce an initial flow velocity in the gaseous well,
- the velocity string being adjustable to at least one second state with at least one second cross-sectional dimension when deployed in the production tubing,
- the at least one second cross-sectional dimension decreasing the reduced flow area and configured to produce at least one subsequent flow velocity in the gaseous well.
A fluid lift system for a gaseous well, the system comprising:
- a velocity string deploying in production tubing of the gaseous well and reducing a flow area in which produced fluid is lifted at least partially toward the surface;
- and
- means for adjusting a cross-sectional dimension of the velocity string while deployed in the production tubing to decrease the reduced flow area in which the produced fluid is lifted at least partially toward the surface.
Dependencies are inferred from the claim text.