What Are The Different Methods Of Subsea Leak Detection?

Joshua Horton

Subsea leak detection is a very important task. Seepage during construction can lead to irreparable damage and loss of life, and it is important to prevent this and minimize the damage once it has happened.

There are several methods to detect leaks, some better than others. The best method is the one that will be the most efficient, cost-effective and best suited to the type of subsea work.

In this blog post, we will look at some of the available methods and explain how certain techniques are more suited to certain uses.

Pressure Testing

This method involves placing a small amount of fluid under pressure and testing the fluid’s ability to leave through a leak. This is done by inserting a small tube into the hole and pumping it down with a vacuum pump.

The amount of pressure required to allow the fluid to escape is measured and recorded. This can be used for relatively small leaks and is inexpensive, but it does not work in all situations. It is often used when there are no other options available and when there is no need for real-time data acquisition or analysis of subsea leaks.

Acoustic Leak Detection (ALD)

Acoustic leak detection works by using sound waves to detect where there may be an issue with the surrounding environment or structure. It uses sound waves (usually ultrasound) emitted from an acoustic source, such as a hydrophone or an array of hydrophones placed at different depths around the tested subsea structure.

The waves bounce off nearby objects such as vessels or pipes, returning different signals depending on how much energy they receive from those objects. When there is a leak nearby, this signal will be very strong and will produce a “clicking” sound in the hydrophone array that can be heard by human ears on board vessels nearby (and also sent back via telemetry).

Sonar (Sound Navigation and Ranging)

Sonar is a passive acoustic method that uses sound waves to determine the position of an underwater object. It works by emitting sounds into the water and using a receiver that can detect the echoes that come back from underwater objects to calculate their distance and direction from the source.

The rate of return for echoes depends on how far away the object is and how fast it’s moving through the water (refractive index). A sonar system will use several hydrophones placed around a structure or vessel being tested, with each hydrophone recording different signals depending on its distance from each other.

The signals are then combined to give a more accurate reading of where an object is located underwater relative to where it was initially placed, allowing it to be detected more accurately than just by visual inspection alone. While this system has been used for decades on ships, it has recently been adapted for use at subsea depths.

Infrared Thermography

Infrared thermography is a way to scan an object for a heat signature. It works by scanning the object’s surface with a thermographic sensor and then measuring the temperature difference between different areas on the object. The temperature difference can then calculate how hot or cold an area is.

This allows for a more accurate reading of where an object is located underwater than visual inspection alone due to how heat travels through water at different speeds depending on how far away it is from the source. Infrared thermography has been used in many industries, including archaeology and construction, because it can easily detect objects that are not visually detectable underwater, such as those obscured by sediment or vegetation.

It also allows for more accurate readings of objects underwater than other methods because it does not rely on visual inspection alone and thus can be used more often without dealing with any issues with visibility due to fog or darkness.

What Are The Different Methods Of Subsea Leak Detection?

In the oil and gas industry, subsea leak detection plays an important role in production. While most operators have a preferred leak detection method, each technique has pros and cons. It is important to know that selecting the best one for your application will depend on site-specific factors. If you catch these leaks early on, it can save you a lot of money in the long run.