Since we don’t manufacture noise mitigation products, we are often asked to provide our clients with an honest, unbiased analysis of whether planned noise mitigation will work. As in all areas of business some companies are more honest than others. Some suppliers who sell or rent sound walls exaggerate their claims, or provide acoustical data that doesn’t relate to the real-world situation. If a product works, we’ll be the first to recommend it. If a company is making unlikely claims, we’ll confidently give it a thumbs-down. We have encountered manufacturers who claim their sound walls will reduce low-frequency noise by 20 dBC on oil and gas drilling sites. This claim appears outlandish and should be treated with a great deal of skepticism. A reputable company would not make this claim, and this may be an example of a company citing laboratory test data measured in a way that is unrepresentative of a real-world scenario.
What are the alternatives to acoustical walls?
All noise problems are best solved by reducing sound levels at the source. The most effective options to reduce noise levels include:
Orienting the onsite equipment to direct sound away from residences.
Replacement of offending noisy equipment with quieter systems.
Installation of improved exhaust mufflers.
Installation of specialist noise control systems such as shaker enclosures, and intake silencers on fans and blowers.
These types of noise-reduction systems can require engineering effort. There are also operational implications for the operator, meaning this kind of mitigation may not be implemented until a noise problem already exists. To predict which drill sites will produce noise problems, acoustical consultants perform noise modeling studies. These studies predict noise levels based on known rig noise characteristics and topographical data. The study results enable potential noise issues to be identified well before the rig or fracking equipment moves into the site.
Verification of compliance is often performed during drilling and fracking with the use of noise monitoring systems, which can continuously measure noise and allow real-time remote data viewing. This means when an exceedance of the COGCC limit occurs, the operator is usually the first to know. These systems generally record audio, meaning the noise source producing the exceedance can be verified with some post-event analysis.
What about vibration problems?
Residents living near drilling sites sometimes complain of low-frequency vibration in their homes. This is often experienced as rattling within the home. From our analysis of noise and vibration measurement data we have collected at drilling and fracking sites, it appears this issue is caused by low-frequency airborne noise. When this noise reaches a house, some of it will travel through the walls of the building. This energy can cause windows, picture frames and other furnishings to rattle. While possibly annoying to residents, this level of vibration is far too small to cause any damage to structures.
We have been asked whether these kinds of vibrations could be caused by the drilling head underground. In all cases, we’ve found that the distance between the drill head and the building is far too great for this to be an issue.
Since the vibration issue is linked to the low-frequency noise, the solution to this issue is the same as for low-frequency noise. The challenge for the operator is to contain low-frequency noise within the site.
We hope the above information serves as a good basic guide to the COGCC noise guidelines and the challenges to operators in meeting the limits. For more information, or to discuss your acoustical needs with a consultant, please call us or
send us a message.