ALRDC Technical Library

Document Categories


(14) New Positive-Seal Shroud Hanger Design Solves Production Problem in New Mexico Gas Wells
by: Art Pena, Chengbao Wang — Added 6/13/2009 12:00:00 AMSWPSC - ESP Pumps

Motor shrouds and hangers are commonly used to set ESPs below well perforations in order to maximize drawdown and/or minimize gas interference. In this New Mexico gas field, conventional shroud hangers created multiple problems. Wellbore fluids and gas leaked through conventional hangers and, consequently, a new design was installed and monitored. The new positive-seal shroud:

• efficiently forced wellbore fluid past the motor
• reduced motor temperature 30°F to 50°F
• reduced scaling
• allowed for more accurate equipment sizing, lowering the HP requirement by 50% in some cases
• provided better gas separation
• increased drawdown efficiency
• increased equipment run life and production.

The new design is installed in ten similar wells for three different operators, all producing the same positive results. This paper will detail the production performance of these wells before and after the new installation, as well as the basic design features of the shroud.

by: Brown Lyle Wilson — Added 6/11/2009 12:00:00 AMSWPSC - ESP Pumps

The centrifugal pump is a dynamic pumping device. Two-phase fluids with several orders of magnitude difference in the density of the phases have always been very difficult to pump.

This presentation reviews the historical methods for gas handling and presents information on the gas handling methods and devices recently introduced to the industry.

This information will be of great benefit for anyone involved in the selection and sizing of artificial lift equipment for oil wells and for the de-watering of wells for gas production.

by: Jeff Knight, Duane Bullock, Joe Lisenbee — Added 6/10/2009 12:00:00 AMSWPSC - ESP Pumps

The recirculation electric submersible pump system was introduced to industry in 1996. Subsequently, the system’s utility has been demonstrated in numerous installations, the vast majority of which have occurred in the Permian Basin area of west Texas / Southeast New Mexico. The system can be used to: (1) minimize gas interference with the pump (2) maximize well drawdown (3) increase fluid flow past the motor in low volume wells, and (4) eliminate shrouds. The primary goals of most all existing installations have been either to avoid gas interference with the pump and/or to minimize producing fluid levels.

This paper provides a basic description of the recirculation system. Sample output from a new recirculation pump sizing applet is presented. The benefits of the technology to Permian Basin Operators are demonstrated through several case histories. These examples include applications of the technology in both 5-1/2 in. and 7 in. casing wells.

Tandem Gas Separator Performance for Electrical Submersible Pumps
by: B. L. Wilson, Donn Brown — Added 9/20/2009 12:00:00 AMSWPSC - ESP Pumps

The performance of the centrifugal pump used in Electrical Submersible Pumps (EPS) is significantly degraded by the presence of gas in the fluid. This greatly reduces the applicability of the pump. Rotary separators, separating devices that used the pump shaft rotation to force the gas from the liquid were developed over twenty five years ago. In situations where even the rotary separator could not remove enough gas form the fluid, tandem or stacked rotary separators were often used.

Improved models of rotary gas separators have been developed and introduced. In the development of the new separators, a large body of information was developed on the mechanism involved in the rotary separation. Parts of the lessons learned in the development of these new separators indicate that a tandem separator may be of little if any benefit to downhole gas separation.

This paper reports on gas separator testing performed in a high pressure gas test loop. This testing concentrated on the possi