Fundamentals of Gas Lift Engineering

Well Design and Troubleshooting

Ali Hernandez

• Publisher: Gulf Professional Publishing
• Year: 2016
• ISBN:
  9780128041468
• Topic: Technology & Engineering
• Subtopic: Fossil Fuels
• Index: Technology & Engineering

Fundamentals of Gas Lift Engineering: Well Design and Troubleshooting discusses the important topic of oil and gas reservoirs as they continue to naturally deplete, decline, and mature, and how more oil and gas companies are trying to divert their investments in artificial lift methods to help prolong their assets.

While not much physically has changed since the invention of the King Valve in the 1940s, new developments in analytical procedures, computational tools and software, and many related technologies have completely changed the way production engineers and well operators face the daily design and troubleshooting tasks and challenges of gas lift, which can now be carried out faster, and in a more accurate and productive way, assuming the person is properly trained. This book fulfills this training need with updates on the latest gas lift designs, troubleshooting techniques, and real-world field case studies that can be applied to all levels of situations, including offshore.

Making operational and troubleshooting techniques central to the discussion, the book empowers the engineer, new and experienced, to analyze the challenge involved and make educated adjustments and conclusions in the most economical and practical way. Packed with information on computer utilization, inflow and outflow performance analysis, and worked calculation examples made for training, the book brings fresh air and innovation to a long-standing essential component in a well's lifecycle.

• Covers essential gas lift design, troubleshooting, and the latest developments in R&D
• Provides real-world field experience and techniques to solve both onshore and offshore challenges
• Offers past and present analytical and operational techniques available in an easy-to-read manner
• Features information on computer utilization, inflow and outflow performance analysis, and worked calculation training examples

Chapter 1

Gas properties

Abstract

A description of the hydrocarbon gases that are commonly used as lift gas in most gas lift installations is presented at the beginning of the chapter, including the compositional limits that are used to classify these gas mixtures as corrosive, sweet or sour, or capable of generating hydrate related problems. The general equation of state is presented for ideal and real gases with the use of the compressibility factor and the universal gas constant. The way in which the compressibility factor is calculated from the pseudocritical pressure and temperature of the lift gas mixture is presented. Dalton’s and Amagat’s laws are described and used to solve problems and find the partial pressure of a particular pure gas in the mixture. The molecular weight of a gas mixture is determined from the mole fraction of its individual components. The specific gravity of a mixture of natural gases is defined and different methods that can be used for its calculation are presented. The following additional topics are presented: general equations for the calculation of the gas viscosity, determination of lift gas solubility in water, procedure to determine the water vapor content of a mixture of hydrocarbon gases, procedures to predict the onset of hydrates, and calculation of the gas specific heat ratio.

Keywords

compressibility factor

equation of state

gas specific gravity

gas viscosity

hydrates

molecular weight

partial pressure

specific heat ratio

The working fluid of a gas lift installation is, in most cases, the natural gas associated with the oil that is produced from the same field or from a nearby gas source. The calculation of the injection gas properties is a necessary first step to predict pressures, temperatures, flow rates, etc. at in-situ conditions in the different components of a gas lift installation. Without the knowledge of these properties, it is simply not possible to determine the important parameters that are frequently used in gas lift designs and troubleshooting analyses, such as the ...