Artificial Lift

Major operators in North America performed field case studies for a new coated plunger. During this time pump repair data was collected from Harbison-Fischer’s pump tracker system, while the field operator captured well conditions and parameters through their well tracker system. A total of 28 wells known for premature spray metal plunger failures, due to severe abrasive wear created by high solids concentration have run the new coated plunger since January of 2018.

In the past 10 years, drilling methods have drastically reduced the time it takes to drill wells. This is especially true in today’s unconventional shale market where 20,000 ft wells are being drilled in under 14 days. This increase in drilling rates along with increasing depths and deviations has presented many challenges for the conventional rod lift system, which was designed to last for ten years but are now having issues within the first twenty-four months resulting in substantial increases in workover costs.

In principle, no well is perfectly vertical since deviations in the drilling process are inevitable. Moreover, the number of intentionally deviated wells has steadily increased over the years. Complex three-dimensional borehole trajectories give rise to a number of physical phenomena that are usually negligible when the borehole is intended to be drilled as vertical. Those include three-dimensional vibrations of the rod string and mechanical (or Coulomb) friction between the rods/couplings and the tubing. Also, the impact of gravity becomes more subtle.

Two widely used methods of artificial lift are Electrical Submersible Pumps (ESP) and Sucker Rod Pumps (SRP. Each of these methods frequently require methods to avoid or handle gas for successful operations. Presented here are discussions of methods of gas separation for each method and graphical techniques for prediction of the gas separator performance that will allow the user to better select a workable gas separator system and predict maximum well drawdown with the selected method of lift. 
 

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.

Variable Frequency Drives (VFDs) are an advanced type of beam pump-off controller with the ability to increase or decrease pumping speed. This facilitates drawing down the fluid level to near pump off conditions and maintaining a constant bottom hole pressure, all while running 24 hours per day. VFD’s have been able to successfully reduce the failure frequency in the most problematic wells, and in some cases, increase production as well. This presentation will illustrate a systematic approach to a few common problems when operating VFD controlled wells.

Production rates in unconventional reservoirs are directly related to the reservoir volume stimulated (Stimulated Reservoir volume – SRV) during fracture treatments. Logs and data taken from permanent downhole sensors permit observation of SRV behavior and visualization of interaction, cross flow, interference and inflow performance which have led to strategies that increase total hydrocarbon recovery. We recognize differences with varying reservoir conditions and the need for specific local data.

This paper proposes an analytical methodology that consists of an evaluation of the particle size distribution, viability for the use of sand screens and centrifugal separation systems for sand control management in wells with high sand and fluid production producing through an ESP. All the technical considerations are explained focusing on the information required and the parameters analyzed to recommend the most accurate design for sand control; selected approaches and models that have been developed to improve the runtime due to sand issues.

Gas production is one of the main problems on ESP systems; causing premature failures and low efficiency, these are the reasons why many companies have developed a number of solutions to separate gas before reaches the pump. To solve this problem a New Downhole Gas Regulator has been developed in order to avoid large amounts of free gas flowing directly into the pump intake. This system regulates the amount of gas ingested by the pump so it will make easier for the pump stages to lift a fluid with a higher density (Less amount of gas in the multiphase flow).

Horizontal Unconventional declines have a rapidly declining hyperbolic decline section and a slower declining exponential decline section. Rapidly changing production volumes from the decline curve and more rapid changes from slugging gas as a result of undulations in the horizontal leg plus sand from massive frac jobs result in challenges in artificial lift selection. This paper will explore these challenges.