Artificial Lift

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.

Production tubing failure is a common issue in reciprocating rod lift wells due to high-friction, metal to metal contact with sucker rod couplings during the pumping stroke. This excessive tubing wear typically leads to a hole in the tubing wall resulting in high workover costs. A sucker rod coupling with a unique low-friction and high-hardness diamond-like coating (DLC) was tested in a side-loaded reciprocating environment.

Continuous sucker rod is primarily used as a solution in deviated (unconventional) rod lift wells plagued with rod and tubing failures. It is commercially available in two shapes - round and semi-elliptical (elliptical). For 40 years, the uniquely shaped elliptical continuous rod has been offered as a primary choice for reciprocating rod lift (RRL) applications and touted as a better product over round continuous rod with benefits that until now have not been made public.

A new gas separation technology was released last year with the goal of creating a substantially increased volume capacity and therefore significantly improved separation quality through application of a process known as limited-entry.  This process is more commonly applied to well fracturing and other stimulation procedures wherein the principle is applied to create an equal distribution of fluids to be pumped into an expansive length of producing formation.  

Daily run time on beam pumped wells is a leading indicator of equipment performance as well as reservoir performance. Changes in run time can point to many different causes. Some are due to failed down hole equipment, but not always. Misdiagnosing these changes can lead to unnecessary OPEX spend and production loss. Beam pumped wells with variable speed drives can be analyzed in the same manner by evaluating the daily average SPM. Methods, Procedures, Process Run time changes can be easily identified with multiple programs, reports, etc. Once identified, they must be analyzed.

Rod pumping with fiberglass rods is an industry accepted alternative to rod pumping with metal rods. Fiberglass tapers/strings are mainly utilized to overcome design limitations of existing beam lift equipment when additional lift capacity is required. Fiberglass rods are lighter and stretch more than metal rods resulting in lower loads and higher downhole stroke lengths. Economic analyses for new installations or repair jobs must take into account the run life of fiberglass rods.