Artificial Lift: HP/HT Pollution Control

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Enhanced well production is vital in today’s oil field. The vast majority—an estimated 90% or more—of the world’s oil and gas wells rely on some form of artificial lift operations to unlock their full potential. Hundreds of thousands of relatively low-flow-rate wells require artificial lift to maintain any production at all. Even the most prolific wells will eventually lose pressure over time, requiring artificial lift to produce higher flow rates and meet production targets. 

To optimize the recovery and life span of producing wells amid increasingly challenging well environments and the global demand for cleaner energy, operators must adopt innovative artificial lift technologies that maximize both technical and environmental performance. 

The recent breakthroughs in drilling and stimulation technologies require equally advanced artificial lift solutions—especially in corrosive, abrasive or HP/HT environments. While these wells are often the most lucrative, they also come with higher risks and bigger challenges. To successfully usher in the next generation of artificial lift technologies, continuous improvement is essential. 

Reimagining rod lift 

By far, the most common artificial lift method is a rod lift system, which uses a sucker rodstring and downhole pump to pressurize the reservoir and draw more oil and gas to the surface. For most wells that no longer have enough pressure to flow naturally, the rod lift system is an economic and reliable way to increase formation fluid recovery. In fact, approximately three-quarters of all wells employing artificial lift use sucker-rod pump technology. 

In most applications, the rod lift systems are relatively simple, fast and inexpensive to install and operate. However, HP/HT and sour operations pose special challenges. These extreme environments push the operating envelope of conventional rod pumps, which have remained relatively unchanged since their initial development. As the industry moves toward more complex wells (e.g., unconventional, HP/HT and sour gas), innovative, highly engineered artificial lift technologies are required to recover well production safely and efficiently. 

Defying the limits of artificial lift

In rod lift installations, the stuffing box is an essential component of the pump system. It attaches to the wellhead or pumping tee, forming a tight seal against the polish rod. This seal creates a barrier between the well and the surface, directing the produced fluid into the flowline and preventing unwanted downhole fluids and gases from leaking. But conventional stuffing boxes aren’t designed to withstand the industry’s most extreme well conditions. This has a cumulative effect on the entire artificial lift system and, ultimately, the operator’s bottom line.

One artificial lift technology that has proven to improve well performance and environmental safety in harsh applications is the pollution-control, high-pressure stuffing box from SPM Oil & Gas, a Caterpillar company. The stuffing box addresses several key issues that plague conventional stuffing boxes, including pollution exposure, limited service life and narrow operating ranges. 

Significance of sealing support

The SPM Oil and Gas design increases internal sealing support by more than 60%. The pollution-control, high-pressure stuffing box incorporates exceptionally rugged packing material to protect the polish rod from packing wear and tear as it passes through the stuffing box—increasing the life of the polish rod. Internal testing confirmed the new stuffing box design can extend well life by more than four months compared to conventional technologies. By improving overall equipment reliability, the new stuffing box can help operators optimize artificial lift operations by reducing pump equipment maintenance, nonproductive time and deferred production. 

The key design components of the engineered stuffing box include a pollution-control flapper valve, upgraded brass internal leveling plates to optimize polish rod alignments and accessible test ports and grease zerks for more efficient well maintenance. The extended-life stuffing box is rated for wells from 1,500 psi to 5,000 psi—even in operating temperatures up to 350 F (177 C) and high-H₂S conditions—providing safer, more reliable operations for some of the industry’s harshest wells. 

To ensure maximum safety performance, the pollution-control flapper valve shuts off the well in the event of a polish rod break. This failsafe prevents equipment damage and, most importantly, the risk of environmental contamination from the uncontrolled flow of formation fluids. This safeguard feature is especially critical in HP/HT and sour gas wells, which subject well equipment to harsh, corrosive conditions that often result in premature equipment failures and costly replacements. 

Future of artificial lift

As operators examine new ways to improve the economics and environmental performance of new and existing wells, advances in artificial lift are especially valuable. Artificial lift is seeing a major resurgence—and the use of rod pumps is expected to grow substantially. 

In today’s oilfield environment, emerging artificial lift technologies have the potential to make or break a well’s economic viability. The SPM Oil & Gas pollution-control, high-pressure stuffing box is one example of how a single tool can transform an entire operation. 

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