Distributed acoustic sensing

The development of modern technology and an ever-increasing need for larger volumes of production drive the optical fiber technologies forward towards more precise measurement. Optical fiber technology has been rapidly developing for the past 30 years and now approaches the theoretical limits in terms of attenuation and precision manufacturing. The refinements have been taken advantage of in many non-transmission applications, where optical fiber sensing has come to the forefront of numerous industries and applications.

There are numerous embodiments of fiber optic technologies in modern industries, that include distributed temperature sensors, FBG strain sensors, FBG strain sensors, FBG pressure sensors, FBG interrogators, FBG multiplexers, etc. One of them – Distributed Acoustic Sensing (DAS) – provides near real-time measurements by using optical fiber by taking advantage of its low attenuation and long reach. The dielectric nature of distributed acoustic sensing and its immunity to radiofrequency and electromagnetic interference also present an important benefit of DAS to multiple applications.

The technology behind distributed acoustic sensing relies on coupling coherent laser energy pulses into an optical fiber and analyzing naturally-occurring Rayleigh backscatter. As light travels from the input to the distal end, it interacts with fiber, which causes a small amount of light to backscatter. The light that returns to the input end is detected and analyzed. Acoustic waves interact with the material that constitutes the fiber create changes in the refractive index. The changes in the refractive index have an effect on the backscatter characteristics that become detectable for the system. The time-domain techniques are then used to determine the location of the event, which provides fully distributed sensing with a resolution of 1 meter or less.

Distributed acoustic sensing has been found useful and necessary for many different applications, some of which include:

  1. Oil and gas monitoring;
  2. Perimeter security;
  3. Wells monitoring;
  4. Powerlines monitoring.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line: fiber Bragg grating sensors, FBG interrogators, and multiplexers, Distributed Temperature Sensing (DTS) systems. We create and supply a broad variety of top-notch fiber optic solutions for the monitoring of various facilities all over the world.

We provide a distributed acoustic sensing system that is much less expensive than other analogous systems present on the market. If you are interested in Optromix distributed acoustic sensing system, please contact us at info@optromix.com

Distributed fiber optic sensing (DFOS equipment) for oil & gas industry

Distributed fiber optic sensing (DFOS) presents a good ability for the oil and gas industry to operate and optimize its resources more effectively going forward. Expenses on DFOS by the oil and gas industry worldwide was $341.2m in 2015. The rise of expensive multilateral hydraulic fracturing, an ever-greater focus on improving oil recovery and the continued strength of capital expenditure on thermally enhanced oil recovery techniques provide the main markets for the uptake of DFOS over the next 10 years.

During the past five years distributed acoustic sensing (DAS) – one type of DFOS – has approved itself as a pipeline in-service surveillance and monitoring system. Moreover, distributed acoustic sensing as technology looks set to add value to DFOS monitoring solutions of wells and reservoirs. DTS (distributed temperature sensing) is already established as a well-monitoring technique and the complementary application of a DAS interrogation enhances the future business case. The last main type of DFOS equipment – distributed temperature and strain sensing (DTSS) – is competing for market share as well as being able to market itself as a solution that can anticipate structural problems with the oil and gas industry before they occur.

The application opportunities within the oil and gas industry for DFOS are poised to enable a substantive growth in spending on DFOS equipment. After well monitoring, permanent reservoir monitoring and seismic acquisition is an especially exciting venture market for DFOS, as is the use of fiber optics for monitoring offshore infrastructure and downstream process integrity. The use of DFOS as part of a 4D solution and vertical seismic profiling is the most deserving attention market space growth ability for DFOS equipment expenditure over the coming 10 years.

For emphasis: an oil price of $100 per barrel continues to enable exploration and production expenditure on unconventional oil and gas development, thermal enhanced oil recovery (EOR), and ever more IOR (Improved Oil Recovery) activity. Distributed fiber optic sensing is a part of this story: a tool to better the industry’s understanding of how to optimize recovery and improve development techniques.