The coming of the industrial age ushered in an insidious threat: noise pollution. Whether the noise emanates from a nearby railway, superhighway, manufacturing company, or construction operation, it impinges upon the population and does damage. The insidiousness of the damage can be appreciated when one considers the marvelous entity that is the human brain. Almost without exception the human brain is able to adapt to considerable noise by “tuning it out.” The ability to tune out noise is what allows us to sleep on a plane, a train, or even a drilling rig.

So if we can tune out objectionable noise, where is the damage? Our ears detect it and send a message to our brains, causing them to work even if we have tuned out the sound from our consciousness. People who are exposed to levels of background sound called “white noise” suffer heightened stress even while sleeping and, in time, can suffer physiological damage. Such damage can manifest in many ways, including fatigue, shortness of temper, or inability to concentrate.

Management 1

FIGURE 1. The spectrum of noise levels is shown on a relative scale in well-known situations. Drilling, completion, or compressor noise greater than 55 dB at the wall of a residential, commercial, or municipal property may create a level of agitation. (Images courtesy of Principle Energy Services)

The threat of noise pollution has energized society to act. Everywhere we see noise-absorbing media or sound-reflecting walls. Cities erect walls along freeway rights-of-way to shield homes and apartment complexes from the hum of traffic. Landscapers plant rows of sound-absorbing trees or hedges to act as sound barriers while adding to the natural beauty of the area. The mitigation of noise pollution has become a significant business.

Too much noise?

It does not take much noise to cause stress. Sometimes people directly involved in causing the noise are more tolerant of its effects, but tolerance does not mitigate the damage that can be done to the listener. Figure 1 describes the spectrum of noise and relates various levels to well-known situations.

Perhaps it is counterintuitive, but studies have shown that a steady low noise may be more damaging than an infrequent loud noise. Manufacturing or construction activities are conducted during normal working hours when a certain amount of noise is more tolerable since people are normally awake.

If people understand the source, they are able to rationalize the noise and accept it because they know the cause and perceive it is a temporary inconvenience. For example, people living in a new subdivision rarely complain about the sound of carpenters’ hammers as a neighboring home is built. They know that in due time the sounds will cease. There is a certain level of acceptance for noises considered normal, particularly if they are temporary.

The fact that noises fall into a large number of classes and categories can result in very subjective reactions from the general public. Who is to say whether a noise source is acceptable or unacceptable?

Management 2a

FIGURE 2. Before any work is done, Principle Energy Services plans an engineered approach to mitigate the sound at an unaltered site.

Objectivity solves a problem

It is safe to say that commercial activities typically generate the kind and volume of noise that annoys the public. Most companies want to be good neighbors and are willing to take steps to mitigate or eliminate industrial noises. Solutions can be extremely elaborate and costly. For example, when oil companies were developing the Los Angeles field in California, they built sound-proofed shell buildings along Sunset Boulevard. From the outside they looked like typical high-rise office buildings, but they were completely hollow and concealed a full drilling rig.

Service trucks were required to have noise suppression systems so their temporary presence would not overcome the soundproofing.

Such elaborate tactics to mitigate undesirable sounds may be necessary, especially in densely populated areas. But what about drilling and production activities conducted in more traditional locales?

This is where a scientific approach can solve the problem at minimal cost. Leading environmental services companies perform detailed site surveys before any drilling and production equipment and vehicles are delivered to the site. Starting at the planned site of the future wellhead, any homes or public buildings that may be affected are first identified and placed on a detailed contour map of the area. The companies ensure that the most current municipal and state ordinances governing allowable noise levels are verified. The good news is that 75% of the time, it is found that the proposed drilling activity will not affect the neighboring populace.

Management 2b

After mitigation work, decibel levels are below a level of agitation behind the sound barrier (red line on southeast corner of pad)

In the remaining 25% of instances where a risk of noise pollution exists, the company designs a barrier to reduce noise to acceptable levels at each affected building or residence. In most cases it is not necessary to completely surround the rig site with a barrier. A directional approach using a partial barrier may result in an acceptable solution.

The proposed drill site is modeled using noise impact and prediction software that can build a site-specific noise management plan and verify its effectiveness. Typical drill-site sounds can be emulated and their effect measured with the proposed mitigation media in place to confirm its effectiveness before a single barrier is erected. The model takes into account the effects of differences in elevation, intervening trees and underbrush, the direction and intensity of the prevailing winds, and seasonal considerations.

The result of the modeling is a recommended design for noise mitigation to acceptable levels. Operators can choose permanent or temporary barrier solutions depending on their needs. After the sound mitigation system is erected, the environmental services company may monitor noise levels for 24-hour or 72-hour periods to evaluate the barriers’ effectiveness. A compliance noise level survey can be produced from these data to submit to regulatory authorities, if necessary.

Typical barriers fall into two categories: reflective and absorptive. As their names imply, each mitigates sound by either reflecting it away from built-up areas or deadening the sound through absorption. The barrier media is modular to facilitate transportation and erection. This feature also allows barrier modules to be relocated to other sites where they can be configured to manage sound from that location according to that location’s predictive model and site survey.

Management 3

FIGURE 3. Nonpermanent sound barriers can be installed quickly and then removed and reconfigured for the next site.

Being a good neighbor

A proactive approach that anticipates and mitigates annoyances before they occur is the hallmark of a good neighbor policy. Companies that engrain good neighbor practices into their culture build strong, positive reputations that can weather the occasional complaint. Most fair-minded citizens are willing to give the benefit of the doubt to enterprises that demonstrate they are keen to be good neighbors by taking positive steps to engender good relationships from the beginning with those who live and work around their facilities and operations.

In the oil field Principle Energy Services helps operators be good neighbors by first measuring and modeling the potential for noise pollution and then engineering solutions that mitigate noise from a level of agitation to a level of comfort. Its M3 Noise Solution process identifies potential problems and helps evaluate cost-effective solutions.