Artificial Lift

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.

Data from fluid level, dynamometer, pressure, and motor power measurements were acquired by a standalone programmable monitoring system that uses internet and cellphone communication with the Cloud for remote monitoring of well performance. The paper presents results from the tests that lasted several weeks, beginning with well pump down, just after new pump installation and continuing during normal production operation.  The performance of the well was monitored in detail and additional measurements were acquired as needed based on the real time performance of the pumping system. 

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.

In reciprocating rod lift, the On-Off tool is a device that allows the operator to easily disconnect the rod string from the pump. This is especially advantageous in an oversized tubing pump application or when used in conjunction with an insert pump in the case of the pump becoming stuck. It is important for the end user to understand the cause of some typical On-Off tool failure modes, which will allow for a better understanding of proper tool selection. 

This paper Introduces a successful new chemical technology applied in ESP, SRP and GLV systems. The technology uses a microencapsulation method which creates a solid chemical treatment conformed by a specific chemical formulation designed especially for each case, this solid component is introduced in a Chemical Screen body and then is installed at the end of tubing. The new downhole treatment technology was designed and successfully applied in 25 wells in the Permian Basin to control scale and corrosion, achieving run times of more than 365 days.

Different types of forces NOT accounted for by the wave equation are 1) mechanical friction, 2) piston force acting on the polished rod due to tubing back pressure and 3) true vertical rod weight.  Mechanical friction will be discussed from 1) over-tight stuffing box, 2) down hole sticking due to a severe dogleg in the wellbore profile and 3) friction from paraffin along a section of the rod string.