ALRDC Technical Library

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A Review of D.O.E Testing of VortexFlow Technology for Petroleum and Natural Gas Production and Operations
by: Norman Hein — Added 9/20/2009 12:00:00 AMSWPSC - Critical Velocity

New, patented technology developments on forming spiral flow in surface flowlines and pipelines as well as downhole to extend critical flow have been tested in a variety of programs by the Department of Energy (D.O.E.), with associations with the Stripper Well Consortium, Universities, and the Rocky Mountain Oilfield Testing Center. This presentation will provide a summary of this testing from 2002 through 2006. This will cover artificial lift applications to extend flowing wells, lower critical flow requirements to unload wells and production operations on mitigating paraffin and line freezing, as well as stagnant fluids removal. Finally, future testing of the various devices will be presented.

Critical Velocity Reducing System for Liquid-Loading Gas Wells
by: T. Scott Campbell — Added 9/20/2009 12:00:00 AMSWPSC - Critical Velocity

Liquid loading in an extended perforation interval gas well is not easily fixed. Extreme perforation intervals (500 to 6,000 ft) and the larger internal diameter of the production casing often render the well incapable of producing the gas rates required for effectively lifting produced fluid to surface. Operators continually struggle with deciding where to place the end of the production tubing and choosing the best type of artificial lift system for producing these wells. The most common methods used to combat liquid loading problems in extended perforation interval gas wells are plunger lift, soap injection (either batch or capillary injection), and flow-area reduction (dead strings or velocity strings). Each of these production methods has been proven successful in fighting liquid loading problems independently of the others, but each has limitations that will reduce its effectiveness over time as well conditions change.

Weatherford has designed a new bottomhole assembly that su

Uncertainty in Gas Well Critical Velocity Predictions
by: Joe McInerney, James Lea, James C. Cox — Added 6/13/2009 12:00:00 AMSWPSC - Critical Velocity

Critical velocity in a producing gas well has been defined originally by Turner et al. as the gas velocity to carry small droplets of liquid upward. If you try to produce below the predicted value, the droplets are predicted to fall in the well and accumulate in the tubing and create liquid loading problems.

Correlations such as Turner et at., Coleman et al, and results from Shell are compared. It is shown that at low pressures, projections for the required critical velocity differ the most. To provide some additional information on the situation, some low pressure laboratory measurements in 2 3/8’s tubing are made and compared to the existing prediction methods. The reader will have a better idea of what accuracy is expected when trying to predict critical gas well velocity or production rate requirements from available correlations.