Safe and sound

Workers within the oil and gas industry are exposed to countless hazards on a daily basis, none more so than excessive noise, as Lee Nicholson explains

The risks associated with working in the oil and gas industry are extensive; every day offshore workers are exposed to loud turbines, pumps, pipes, valves, helicopters and mechanical noise for prolonged periods of time. Strict rules governing the use of hearing protection are in place, however, noise induced hearing loss remains a significant problem for the industry, leading to a call for the continued development of effective noise control measures.

Noise remains a prevalent issue in the offshore industry. In fact, research from the Health and Safety Executive (HSE) estimates that over 30 per cent of workers in the offshore sector are exposed to noise levels in excess of the upper action limit of 85 dB (A). While it is predicted that 120 million people worldwide have disabling hearing difficulties.

At a time when the offshore oil and gas industry is seeking to access newer, complex fields, often in deeper waters this necessity for noise control solutions is becoming even more essential. Such explorations often require equipment operating at higher pressures and temperatures, thereby creating even more difficult and noisy conditions in which to operate. Add to this a projected growth in Floating, Production, Storage and Offloading (FPSO) facilities, and the challenges remain significant, while the opportunities for improved occupational health of staff and overall business productivity become greater.

The main challenges with such noise levels, which often exceed the exposure limit of 87dB (A) as outlined in The Control of Noise at Work Regulations 2015, is the negative health impacts it can have on the personnel working at oil and gas facilities. Prolonged exposure to excessive noise can often lead to irreversible hearing damage and tinnitus, as well as more serious conditions such as permanent hearing loss (NIHL), cardiovascular diseases, sleep disturbance, stress, brain impairment and mental issues.

Faced with such challenges, an increased emphasis has been placed on addressing noise at source in the offshore sector, with innovative solutions coming to the fore to both reduce noise exposure levels and in turn the number of noise-related injuries throughout the oil and gas industry.

Silencing noise in the offshore sector
The advantages of reducing excessive noise within the oil and gas industry are extensive, not only to safeguard the health and safety of employees, but also to increase productivity and comply with increasingly rigorous regulations in order to avoid financial penalties and reputational damage.

Given the increasing demand for higher performance, and the fact that increased power output from offshore machinery leads to higher noise emissions, machinery manufacturers are looking at packaged acoustic enclosure options to mitigate the noise risk and save space.

A number of solutions, ranging from on-skid mounted localised acoustics enclosures, on-skid localised acoustic screening, and both skid mounted and deck mounted fully encompassing acoustic enclosures, designed to be accessible by personnel for equipment maintenance purposes, are often installed to combat the detrimental affects of noise.

The requirement for skid mounted acoustic enclosures is becoming more widespread, and as such operators require these enclosures to be designed with the highest level of safety in mind.

Working within the space constraints, which are common to these types of installation, can be particularly challenging. Whilst not losing sight of stringent working environment specifications in relation to personnel, all the ancillary safety equipment and features must be tightly packaged within each enclosure.

In certain applications it is necessary to consider accidental loads in conjunction with environmental loads. In relation to the design of acoustic enclosures, the most critical accidental loads to be considered in most offshore applications are blast loads. Through the process of design and utilisation of Finite Element Analysis (FEA) methods for both static and transient structural analysis, manufactured enclosures are designed to meet the specification requirements for the most onerous of blast load incidents.

These designs must not only consider the inherent noise of the equipment and the desired maximum noise levels required in different areas of the structure, but also the logistical and spatial limitations in terms of access to, from and around the rig. Therefore, the correct design and selection of acoustic products in particular housings for plant items is essential. This must be achieved first time to avoid the serious implications of non-compliance of specifications and the excessively costly nature of retro fitting.

There is no margin for error and with this in mind products performance must be tested to BS EN ISO 11546- 1:2009, as required by BS EN ISO 15667 ‘Acoustics – guidelines for noise control by enclosures and cabins’.

Johan Sverdrup oil field
A prime example of such noise control solutions in action is one of Wakefield Acoustics recent projects for the Johan Sverdrup oil field.

The Johan Sverdrup oil field, located on the Norwegian continental shelf, is one of the largest oil discoveries ever made in the region and is expected to generate between 550-650 barrels per day at its peak over the course of the next 50 years.

To significantly reduce noise levels on the offshore platform, and in turn protect the welfare of their workforce, the operator for the Johan Sverdrup development required 17 high specification acoustic enclosures for the high pressure pumping applications

The challenges inherent with the supply of noise control solutions to such a highly productive offshore application are vast. Due to extensive health and safety demands, Wakefield Acoustics designed the enclosures to withstand the client specified blast loads in the event of an explosion.

Operating in a challenging climatic North Sea environment, with extensive noisy equipment in a space-constrained environment, the acoustic enclosures on the project were designed in accordance with stringent NORSOK standards.

The packaged enclosure options – fabricated from corrosion resistant materials – also incorporated safety features, which are typical for such hazardous area applications, with hazardous area compliant ventilation systems and filtration, internal lighting and emergency back-up lighting, removable sections for regular and major maintenance requirements, as well as fire and gas detection and suppression systems.

A number of leading companies in the oil and gas sector have opted to use Wakefield Acoustics due to their vast experience and knowledge in the industry. Based on their expertise and considerable application experience, the company has supplied a large number of noise control solutions including enclosures, inlet silencers, inlet filter silencers and blow off silencers for a wide range of offshore applications around the world.

The offshore oil and gas sector will unquestionably see dramatic changes in the coming years, as companies hunt oil and gas that is harder to extract from hidden away and more challenging formations. Such shifts mean that working conditions will noticeably evolve, as higher performance equipment and machinery requiring increased power input is needed, greatly increasing the noise generated on offshore applications. Noise therefore will become a critical factor for oil and gas companies to address increasingly through the design and development of offshore facilities.

Wakefield Acoustics
Lee Nicholson is managing director of Wakefield Acoustics, a leader in noise control solutions for the offshore oil and gas industry. The company has extensive experience in providing innovative noise control engineering solutions spanning a wide variety of sectors including oil and gas, petro-chemical, power generation, water and waste, recycling, general industry and infrastructure.

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