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Title: Better downhole gas separation optimizes production

Journal Article · · Petroleum Engineer International; (United States)
OSTI ID:7279442
 [1]
  1. Coastal Management Corp., Midland, TX (United States)

Pumping efficiency, impaired by gas produced through a downhole pump, can be improved with subsurface separators and gas anchors. The result is longer equipment life and enhanced well productivity. The physical mechanism that separates free or solution gas from fluids in a well is a gas separator, which operates by virtue of gas and fluid velocities in the well bore and downhole production equipment. When oil containing solution gas crosses the perforations or slots in a mud anchor, a pressure drop occurs, resulting in the evolution of free gas bubbles. Agitation, direction changes and sudden velocity increases also aid the evolution of free gas. Depending upon bubble size and shape and fluid viscosity and velocity, the free gas bubbles will attempt to migrate upward while the fluid moves down. If the downward fluid velocity exceeds the critical velocity required for upward gas bubble migration, free gas will be forced through the production equipment. For wells producing a water cut greater than 20%, the critical downward fluid velocity is 0.5 ft/sec. For wells producing water cuts less than 20%, the critical fluid velocity is 0.5 ft/sec divided by the fluid viscosity (in centipoise). Therefore, successful gas separation may be achieved by employing gas separators that ensure downward fluid velocities that do not exceed the above critical velocities.

OSTI ID:
7279442
Journal Information:
Petroleum Engineer International; (United States), Vol. 66:3; ISSN 0164-8322
Country of Publication:
United States
Language:
English