Subsea Leak Detection: Protecting Our Oceans

While operators take precautions and do regular subsea inspections to avoid leakage, accidents occasionally occur. A generally negative reception and corresponding economic consequences are inevitable when this occurs.

Each day, oil and gas man-made structures across the world face the risk of subsea leaks, an issue that costs the industry billions of dollars and wastes precious oil. For subsea leak detection, the right tools must be used. The question is why is it so difficult to find leaks that occur deep below?

Leaks are difficult to detect as they take time to appear and often occur on inconspicuous platforms or barges. This piece will examine the function and importance of leak detection systems installed deep below the ocean’s surface.

Understanding the Value of a Leak Detection System

If a leak is detected and its location is determined quickly, the damage done to marine life may be mitigated. The type of asset that has to be monitored and the area where leakage or seepage occurs dictate the best leak detection technology to use. Several underwater noise measurement strategies may be used to determine when to intervene.

Many leak detection devices can locate even the tiniest leaks in the harshest maritime and other severe environments. Over several years, the methods have been refined, and the groups involved have been granted worldwide patents for their efforts.

Acoustic Leak Detection

With a directional hydrophone, which listens for ultrasounds produced by leaky fluids moving through an aperture under stress, ultrasonic leak detection may identify leaks in a pipeline. Leaks often have audible sounds at frequencies higher than 30kHz.

The program employs inspection techniques for identifying leak-generated sound from ambient noise, such as that generated by an ROV or surface boat.

Advanced acoustic equipment and algorithms are required to successfully distinguish leak-produced noises from ambient sounds since the acoustic impact signals created by minor leaks are often at frequencies much beyond the hearing range.

The sound from the accompanying (ROV) vessel and other nearby boats is the main disadvantage of this method. Although this approach was formerly ineffective, advancements in data processing and spectral analysis have made it a good alternative.

Fluorescent Detection

The core of the leak detection mechanism is a group of long-range underwater fluorometers. Low quantities of liquid hydrocarbons and a wide range of fluorescent leak-detecting dyes trigger a response from the sensors.

A new generation of long-range remote-sensing fluorometers gives fluorescence sensor systems an edge by allowing for the discovery of minimal concentrations in unclear environments with a broad geographical footprint.

Since the research vessels have such a wide field of view, and the fluorescence detector is mounted on the ROV’s manip, checking for leaks may be done quickly and easily without taking tidal flow direction into account, as is needed by conventional fluorometers.

Long-range fluorescence detection has many other benefits. This includes identifying leaks from risers while operating at a comfortable distance and detecting leaks inside restricted facilities where ROV entry is either not feasible or is too dangerous.

Hydrocarbon Leak Detection

Hydrocarbons in the offshore oil and gas assessment site may be roughly classified into three categories: oil, gas, and combinations of both (multi-phase), and the technology utilized for hydrocarbon leak inspection will vary depending on the most common form.

Among the many applications for the Long Ranger fluorometer is detecting leaks in crude oil pipelines, lubricating fluids, hydrocarbon-based control fluids, and so on. Sniffit, a direct-reading hydrocarbon leak sensor, has been introduced to Oceanographics’ portfolio of leak detection devices for gas.

The Sniffit can monitor for gaseous hydrocarbon leaks in water and provide results in real time. Although the device is best used for detecting methane, it is also sensitive to the presence of other gaseous hydrocarbons.

Leakage Contingency Planning

As a part of the hydro testing specialized operations of the subsea installation, a leak contingency plan is discussed. Injecting a dye, perhaps a fluorescent one, and then visually analyzing its effects is a common method for determining if further intervention is required.

Leaks in existing installations are notoriously difficult to detect visually since they do not often occur at the correct depth. It’s not easy to see the dye’s temperature marks in the water column.

Importantly, if visibility is low, this may indicate that burial and current are likely. Therefore, following a failed hydro test, a thorough visual inspection should be conducted and subsea leak detection services should be contacted.

A professional leak detection service ensures accurate leak identification at an affordable price because they use their own acquisition equipment.