Artificial Lift

Mechanical components used in artificial lift face significant environmental and functional challenges, primarily caused by factors such as corrosion, abrasion, erosion, and stress corrosion cracking in downhole conditions. To ensure a component remains operational, the material not only needs to meet mechanical requirements but also needs surface properties capable of withstanding the corrosive and abrasive downhole environment.

Sucker rod pumping for horizontal wells has advanced considerably over the past few years. Advancements in sucker rod pump technologies and bottomhole assembly (BHA) components/configurations have allowed for more efficient downhole gas separation and greater production drawdowns. The unintended consequence has been an escalation of solids in the produced fluids with increased failure frequencies.

The Polished Rod Transducer (PRT) is a practical and effective tool for well analysis, offering the ability to acquire dynamometer data quickly with minimal disruption to pumping operations. This paper provides guidance on best practices for obtaining reliable PRT readings and improving diagnostic accuracy.

Building upon the successes of cathodically protected rod strings in rotary applications, this study extends the evaluation to reciprocating sucker rod pump operations using anode-coated coiled rod strings. The paper presents results from a pilot project involving four wells for a major California oil and gas producer, achieving a remarkable 11-fold improvement in Mean Time to Failure (MTF) compared to historical performance.

Downhole separation is a critical process for proper sucker rod pump operation. This technology has been successfully applied in vertical wells, providing a solution for gas interference. New horizontal wells present a new challenge to this technology, since slug flow is a predominant flow pattern when sucker rod pumps are implemented. Many experimental studies have been conducted in the past that consider the continuous injection of gas and liquid near the separator inlet.

As rod lift systems are extended to greater depths and tasked with higher production rates, operators face increasing complexity in maintaining reliability and cost-effectiveness. Elevated loads, deeper pump landings, and aggressive environments introduce compounded risks, including rod and tubing wear, bending fatigue failures, corrosion fatigue, and connection reliability issues, among others.

Sand production has been recognized by the oil and gas industry as one of the most significant challenges affecting the operation, efficiency, and longevity of unconventional rod-pumped wells. As sand and other solid particles migrate into the pump assembly, they create abrasive conditions that accelerate wear on critical components. This abrasion not only reduces pump efficiency but also increases the risk of premature equipment failure, unplanned downtime, and costly maintenance interventions. 

A major Bakken operator repeatedly experienced insufficient pump fillage and lower-than-anticipated production volumes in rod-pumped horizontal wells due to poor gas and sand separation. Unable to achieve the desired results after deploying a variety of different gas- and sand-mitigation techniques, the operator partnered with Endurance Lift Solutions to deploy the patented ELS Guardian™ separator in combination with the Triple Bypass tubing-anchor catcher.

The oil and gas industry has used Variable Frequency Drives (VFDs) for decades to match production to inflow. In sucker rod pump applications, it is well understood that optimizing pumping speed dramatically improves pump efficiency and failure rate. However, the same technology provides the opportunity to make multiple speed changes in a pumping cycle.

This study evaluates a 3-1/2 in. tubing well converted from continuous gas lift to plunger-assisted gas lift (PAGL) using a bypass plunger that initially failed to complete cycles under flowing conditions. The objective is to diagnose the root cause, determine operational boundaries for PAGL in 3-1/2 in. tubing, and assess the feasibility of PAGL relative to tubing replacement and higher gas-injection strategies using field data and plunger lift mechanistic models.