Artificial Lift

Corrosion and fatigue are the primary causes of sucker rod failures in artificial lift systems. Harsh well fluid conditions lead to material loss and detrimental pitting which then lead to initiation points for fatigue fractures to occur.

Production in aggressive service environments with higher acid gas concentrations associated with increased levels of hydrogen sulfide (H2S) and carbon dioxide (CO2) requires good fatigue life associated with corrosion resistance. 

This paper proposes a new method to deal with sand and chemical problems in the ESP. The protection system consists of 1) ESP sand separation system that works in two stages assuring the best sand separation efficiency. The first separation stage is composed of a V-wire geometry screened designed based on production. The second stage is a centrifugal system formed by a sand cutting resistance sleeve and a helix that creates a Vortex Effect.

The technology is used to prevent damages in equipment by breaking the gas/sand slugs, creating homogeneous flow regime to allow proper motor cooling, eliminate the risk of gas locking and increase lifting efficiency.

Rod pumping in horizontal wells in the Permian Basin is extremely challenging. So much so that other forms are often considered as alternatives just because of the difficulty. Some of the major difficulties include, gas interference leading to poor pump efficiencies, and greater sand problems leading to premature wear, failures and sticking. When converting from ESP to Rod Lift it is typical to accept a reduction in total production. This conversion typically happens around the 200/300bbls/day +/- range.

This presentation will explore and discuss technology and operational factors that will reduce downhole friction in sucker rod pumping systems resulting in fewer failures and lowering Lease Operating Expenses (LOE) and Workover (W/O) costs. 

Sucker rod pump or “rod pump” is a common method of artificial lift for oil and gas wells in the United States. For decades well analysts and production engineers have looked at surface and downhole dynamometer cards to diagnose various downhole and surface equipment issues alike. In more recent years, helpful rod pump diagnostic tools have aided well analysts and production engineers in training and the analysis of downhole dynamometers utilizing generalized libraries with known behavior for downhole dynamometer cards.

Mechanical Friction in a sucker rod lifted well acting on the rods is not modeled by the wave equation, resulting in the excess frictional loads and horsepower being displayed in the plot of the load versus position at any point along the rod string from the surface to the pump.  When the plunger stops at positions other than at the beginning, top, and end of the stroke, then sticking down hole is frequently the cause.

An overview of the ongoing investigation and analysis into several aspects of gas lift and hole in tubing failures in Delaware Basin. Subjects of investigation will include fluid composition investigation, bacterial corrosion investigation, solids and erosion investigation, and materials and design investigation. Practices regarding the investigation of these failures will be outlined and the limitations thereof will be explained. We will be focusing on corrosion/erosion mechanisms, tubing/GLV design, and the number of different methods taken to date to identify root causes. 

Surface coatings are commonly used in many industries including oil and gas with the aim of hardening the part surfaces to improve wear resistance without compromising the corrosion resistance. Sucker rod pumps employ several parts with coated surfaces as well, including the pump barrels. Both standardized surface modifications and specialty applications for pump barrels are readily available in the market for different well conditions, including extreme well solids and H2S or CO2 service.

As companies seek to optimize performance of rod pumped wells, they examine common problems which may include improper rod string spacing resulting in rod pump damage, rod failures and cable failures of pump off control (POC) wired load cells. Traditional methods of adjusting rod strings requires removal of rod clamps and exposes field personnel to pinch, fall and struck-by hazards.  To mitigate this risk, some E&P companies require a third-party to adjust rod string spacing, resulting in significant expense.