Artificial Lift

This paper will discuss reducing failures in rod pumped wells by using best practices and design changes. The theme of the paper is to share solutions observed over the last 41 years while working with rod pumped wells. These best practices applied from the polished rod through the bottom hole assembly have been proven to improve run time between failures. The topics discussed are improper installation of equipment along with the effect of a properly designed bottom hole assembly. I will also highlight pump designs and accessory items to help with sand and gas issues.

Corrosion fatigue (CF) is an important concern for structures that are exposed to cyclic loads in corrosive environments, especially in the case of oil and gas operations like drilling, offshore risers or sucker rods in artificial lift. Considering the current combination of complex wells completions and the increase of water cuts, the CO2, H2S and Bacteria represent a higher risk for CF failures in sucker rods. This combined effect force operators to choose a steel for either corrosive environments or high loads and increase the chemical inhibition programs.

With the proliferation of production from multiple zones within wells, a major challenge long recognized by industry is to understand which zones are contributing, and how much. This is even more of a challenge with multiphase flow from different zones and with the advent of hydraulic fracturing, correctly identifying which zones have the potential to contribute is critical for future operations. 

Vortex Tools addresses the challenges of managing/optimizing hydrocarbon liquids recovery from horizontal wells with long laterals, thereby increasing their economic value. A 2014 five-well case study with a regional independent found that deploying Vortex downhole DX-I tubing tools (in conjunction with gas lift and plunger) saw beneficial increases in oil & gas production, along with a significant increase in water removal, in horizontal and deviated wells.

Automation is a crucial element to modern production facilities in the Permian Basin.  However, most facilities engineers lack basic understanding of automation and therefore cannot properly design or implement an automated system.  This paper will discuss automation and instrumentation basics as part of a broad automation philosophy to help readers understand how individual components fit into a complete design.  Individual components (or instruments) will be examined to share what options are available to industry and how they can best be utilized.

This is a discussion of a newly developed and field tested system to measure and track fluids produced in the oilfield.  The system’s mission is to track the fluid movement from the cradle to the grave and is, for the most part, a “hands off-no humans needed” custody scheme that provides precise verifiable electronic information to the producer, the trucking company that hauls the fluids, and the companies that handle the final deposition of the fluids, either at the disposal well or the pipeline terminal. 

The balance-ported valve is a gas-lift valve that allows full, available gas injection pressure to be used for the unloading and operating valves.  Using full injection pressure allows for a deeper point of gas injection, which lowers the FBHP, thereby increasing total production.  With standard IPO valves, it is necessary to design the valves with casing pressure drops in order to close the valves as the injection point moves deeper.  The balance-ported valve is configured such that no design casing pressure drops are required for closing.

Some Colombian oilfields have medium to heavy oil production and high gas volume in wells.  Gas production is one of the biggest limitations in an ESP system, as they have difficulty handling a high amount of free gas.  In many cases even when an ESP is used in conjunction with a gas separator and gas handlers, the amount of free gas exceeds the capacity of the system and the performance of the pump is not improved.

Sandy wells are a common problem for any artificial lift system. Calculating the correct allowable volume of sand and solids’ particle size may be the missing link in optimizing run-times and establishing solid pump performance.

Recent Colombian ESP case studies were conducted in fields with high sand/solids presence. Where run times typically lasted 5 months or less, a new design to improve ESP performance introduced a Cup Packer and screens below the ESP sensor.

Downhole sucker rod pump clearance changes from shop conditions to bottom hole conditions due to bottomhole pressure and temperature that the pump components are subjected to. Presented here are equations to estimate the change in dimensions of the plunger and barrel of top and bottom hold down pumps at bottomhole pressure and temperature conditions.