Degasser

Test Your Knowledge

Degassing Quiz

Instructions: Choose the best answer for each question.

1. What is the primary function of a degasser? a) To increase the density of fluids. b) To remove dissolved gases from fluids. c) To add lubrication to fluids. d) To filter impurities from fluids.

2. Which of these is NOT a type of degasser? a) Vacuum degasser b) Flash degasser c) Membrane degasser d) Magnetic degasser

3. How do flash degassers work? a) By exposing the fluid to a vacuum. b) By using a semi-permeable membrane. c) By rapidly depressurizing the fluid. d) By using high-frequency sound waves.

4. Which of these is a benefit of degassing in drilling operations? a) Reduced wellbore instability. b) Increased fluid viscosity. c) Formation of gas pockets. d) Reduced drilling speed.

5. What is a major benefit of degassing for the environment? a) Reduced gas emissions. b) Increased water usage. c) Reduced drilling efficiency. d) Increased equipment wear.

Degassing Exercise

Problem: You are working on a drilling rig and notice that the drilling mud is becoming increasingly foamy, leading to reduced drilling efficiency and potential wellbore instability.

Task:

1. Identify the potential cause of the foamy drilling mud.
2. Explain how a degasser could help solve this problem.
3. Suggest a specific type of degasser that would be suitable for this situation.

Techniques

Chapter 1: Techniques for Degassing in Oil & Gas

This chapter explores the various techniques used for removing dissolved gases from fluids in the oil and gas industry. Each technique relies on different principles to achieve gas separation, with specific advantages and limitations for different applications.

1.1 Vacuum Degassing

• Principle: Vacuum degassing utilizes reduced pressure to decrease the partial pressure of dissolved gases, causing them to vaporize and escape from the liquid.
• Process: The fluid is exposed to a vacuum, often within a sealed chamber. The pressure difference drives the gas out of solution and into the vacuum system for collection or disposal.
• Advantages: Simple design, cost-effective for certain applications, effective for removing volatile gases.
• Disadvantages: Limited capacity, potential for fluid foaming, not effective for highly viscous fluids.

1.2 Flash Degassing

• Principle: Flash degassing relies on a sudden pressure drop to induce gas release. The rapid depressurization causes dissolved gases to vaporize quickly.
• Process: The fluid is passed through a specially designed chamber where the pressure is abruptly reduced, creating a flash of vaporized gas.
• Advantages: High efficiency, can handle large volumes, suitable for various fluid types.
• Disadvantages: Requires careful control of pressure changes, potential for fluid foaming, limited effectiveness for non-volatile gases.

1.3 Membrane Degassing

• Principle: Membrane degassing utilizes selective membranes that allow dissolved gases to pass through while retaining the liquid phase.
• Process: The fluid is passed over a membrane, where the dissolved gases permeate through the membrane and are collected on the other side.
• Advantages: Highly efficient for removing specific gases, minimal energy consumption, suitable for sensitive fluids.
• Disadvantages: Higher initial cost, membrane fouling can occur, limited capacity for large gas volumes.

1.4 Sonic Degassing

• Principle: Sonic degassing employs high-frequency sound waves to disrupt gas bubbles and facilitate their release.
• Process: The fluid is exposed to intense sound waves that create cavitation bubbles, which collapse and release trapped gases.
• Advantages: Effective for removing small gas bubbles, can be used in situ, minimal energy consumption.
• Disadvantages: Requires specialized equipment, not effective for large gas volumes, potential for noise pollution.

1.5 Centrifugal Degassing

• Principle: Centrifugal degassing uses centrifugal force to separate the gas from the liquid phase.
• Process: The fluid is spun at high speeds within a rotating chamber, creating centrifugal force that pushes the less dense gas to the outer edge.
• Advantages: High efficiency, minimal energy consumption, suitable for large fluid volumes.
• Disadvantages: Requires specialized equipment, potential for wear on components, not effective for very viscous fluids.

This chapter provides a foundation for understanding the diverse degassing techniques used in the oil and gas industry. The next chapter will explore specific models and their applications in detail.