Artificial Lift

Problem being addressed: Determining optimized Gas Injection Rate for Gas Lifted wells to maximize lift efficiency. Challenges: While Gas Lift is the most natural artificial lift method, ever-changing surface and downhole conditions cause significant inefficiencies. The changing conditions require frequent adjustments to surface-injected gas rates to maintain the most efficient lifting gradient. If the proper adjustments are not made, these inefficiencies may hinder production and increase lease operating expenses.

There are many potential failures in production wells which result from corrosive downhole environments, mechanical aspects of artificial lift or a combination thereof. Tubing failures constitute a costly failure mechanism in production wells. Tubing inspections can provide valuable insight on the condition of tubing as well as the distinction between causes of tubing degradation. This information is utilized to replace worn and pitted tubing joints, failure root cause analysis and implement solutions to mitigate future failures.

When optimizing a reciprocating rod lift installation, key control parameters must be extracted from the downhole data. Traditionally, downhole data in the form of position and load data is derived from surface data using the wave equation. Downhole position and load data must be carefully analyzed to extract key control parameters for reciprocating rod lift optimization.
IRIS introduces a new and innovative approach for downhole data analysis.

The Artificial Lift Intake Isolation (ALII) tool is a new technology for rod pumping wells that when activated isolates the production tubing. The tool provides positive well control prior to breaking wellhead containment providing significant cost savings, safety and environmental protection. The tool is a simple two-part system, the first being the valve portion which is run just below the client’s pump-seating nipple in the production tubing string. The second is the actuator, which runs on the bottom of the insert rod pump.

A hydrodynamic analysis for different rod guide designs simulating downhole fluid conditions was made using computational fluid dynamics (CFD) analysis, which is widely used for solving the partial differential equations of fluid motion by discrete approximation.  A particular turbulence kinetic energy graphic for each guide sample was created and compared to each other. The results shows a significant difference between the samples and the new rod guide design with conclusive proof of a better hydrodynamic performance. 

The cavitation phenomenon has been extensively studied for many years, however, guidelines on how to implement this existing knowledge to the actual operation of the jet pumping systems in the oilfield are not abundant and, as per the author can see it, not yet being presented in such way that the people that operate these systems in the oilfield could implement on a straight forward way.

The purpose of this paper is to discuss the history of different gas lift design methods and the theory behind a new design method.  In January 2019, Production Lift Companies and Concho Resources ran a new gas lift design method in two unconventional wells in the Permian Basin.  This new method is designed to exploit the initial high bottom hole pressure in unconventional wells to produce higher rates that, before now, were only possible with an ESP.  This life of well design will also follow the well’s decline and efficiently produce the well at lower rates.

Variable Frequency Drives (VFD) are a well-known method of pumping beam wells. By running the well continuously and adjusting pumping speed based on pump fillage, they provide unique benefits to reduce failures in difficult environments as compared to operating in pump-off control (POC); these environments might include solids, buckling tendencies at pump-off, and CO2 WAG environments. Although the industry recognizes the VFD benefits, many candidates remain on POC due to the capital investment required for a VFD purchase.

The ESP system is a mechanical/electrical/hydrodynamic system. It is costly when it fails as the tubing has to be pulled and much or all of the equipment is replaced. 
This paper points out tips in the below various areas that if considered are likely to increase the average run life of ESP Systems

The Apache-operated Adair San Andres Unit (ASAU) currently employs fifteen capillary string (cap string) equipped producing wells, representing 16% of the active producer count. Apache started converting producing wells to cap strings in 2016.  This idea was introduced to Apache at the 2012 CO2 Conference in Midland and later reinforced during a field tour of Whiting’s North Ward Estes CO2 flood in 2015.  The chief benefit using a cap string is production stability.  A review of these installations