Today’s market environment and economics have led to innovative ways to drive the greatest efficiency possible.

With this changing landscape, the rod pump sector has been especially challenged to look at rod lift in a new light.

Deviated and deeper wells, both of which contribute to wear and tear on equipment, especially rod and tubing, lead to higher lease operating expenses.

To address these concerns, Dover Artificial Lift and Liberty Lift have partnered on the Long Stroke pumping system.

The Long Stroke package focuses on fewer cycles, longer strokes and a more comprehensive design to drive better wellsite economics. The key components of this package are the Long Stroke XL Pumping Unit from Liberty Lift combined with the SPIRIT Genesis Integrated Variable Frequency Drive (VFD), heavy-duty rodstring, specially designed pump and bottomhole assemblies. When these components are deployed together, a more efficient and durable system is created resulting in less downtime and more production.

The XL offers a means of managing production costs. Its extra-long stroke length of 306 in. and 366 in., depending on the model, allows the rod pump’s slower travel time to provide more complete fillage and higher volumetric efficiency. The XL is suited for work in deviated, deep, high-volume wells as an alternative to electric submersible pumps (ESPs).

Some of the more traditional applications in which these units have been used are in deeper wells where structural capacity exceeds the limits of conventional units. These units are allowing maximum production potential and efficiency in 3,048-m to 3,657-m (10,000-ft to 11,998-ft) wells in places like Utah, Wyoming and the Bakken Shale where high deviation and depth go hand in hand with more extreme cases than most other North American regions.

Recently, these rod pumping systems have been commonly run in highly deviated applications in which the long and slow stroke reduces overall rod and tubing wear by reducing pumping cycles and rod velocity. Many operators have moved to XL units for more troublesome and deviated wells where they can produce as much or more fluid than a conventional unit, but with greatly reducing pumping cycles resulting in fewer workovers and less deferred production (Figure 1).

The last scenario that is growing in popularity with rod lift is higher volumes at earlier stages in the well’s life. The goal of this application is to reduce the form of lift changes by putting a well on a XL pumping unit earlier or even post-flow to achieve life-of-well savings. These units frequently are run in applications in which wells are achieving 400 bbl/d to 800 bbl/d.

Permian Basin case study

An operator in the Permian Basin was challenged with achieving between 700 bbl/d and 800 bbl/d of production. The operator’s existing ESP method resulted in higher lifting costs and an inefficient system. The operator chose to implement the Long Stroke XL unit, bypassing a conventional 912 pumping unit. The result of the change was successful production of 750 bbl/d to 800 bbl/d. In addition, the move resulted in an overall reduction in capex, an overall reduction in opex by reducing monthly electrical costs, exceeding production goals, elimination or reduction of traditional rod fatigue failures, and a consolidation of artificial lift forms.

When the Long Stroke XL unit was combined with the Dover Artificial Lift Long Stroke package, lower cost and increased production were realized.

Automation

Automation plays a large role in driving the XL unit while simultaneously providing the operator with more enhanced functionality and savings.

The pumping unit has a wireless load cell and provides a position signal via the unit sentry device, eliminating the need for the additional load cell, cables and position device.

In addition, the SPIRIT Genesis controller allows the operator cornering capabilities needed for long-stroke applications, five speed control options as opposed to the industry standard of two, free user interface integration, wireless end devices and enhanced input/output capabilities.

These speed settings allow better gas separation and higher pump volume efficiency because of the speed change capability within one long, slow stroke.

Operators can use the service provider’s technical services team to request a rod design tailored to their particular well scenario.

These designs rely heavily on the wells’ deviation survey, which correlates to the rod guides available for various applications and environments including high temperature, high corrosion and high abrasion. In addition, these units are designed to

  • Reduce tubing wear in high-temperature environments;
  • Facilitate chemical resistance in corrosive environments;
  • Enhance pumping efficiency with flow geometry; and
  • Protect rods for longer with more erodible wear volume.

These tools offer a wide variety of downhole pumps, which can be used in various well conditions including sandy, corrosive or gassy wells, and can alleviate other compromising production issues.

In addition, pump tracking software allows the operator to better manage its assets, improve run times of the rod pump and prevent premature failures. The software enables operators to further reduce costs by recording detailed performance and failure data discovered during pump tear down. This software is available to all pump shops and supports multiple users with different security roles while reducing costs by aggregating data to pinpoint areas of interest.

Dover Artificial Lift and Liberty Lift’s Long Stroke pumping unit is designed to reduce annual strokes by 1.5 million, depending on application. Coupled with the rodstring, the pumping unit extends rod runlife from 66% to 350%, depending on conditions. An integrated VFD with an intelligent pump-off control system at the surface paired with a series of downhole separators allow enhanced remote troubleshooting and surveillance while capturing gas and solids prior to pump entry.

The Long Stroke rod pumping system has helped decrease lease operating expenses through rod and tubing failure reductions. High-production, high-deviation and high-depth well conditions will continue to grow over time. Reducing the cost of change throughout the life of these wells will continue to be the economical driver.

Comments