New Technology Magazine - October 7, 2002

Sabeus To Bring Optical Technology To The Well

Salt Lake City, Utah -- Sabeus Sensor Systems, a division of Sabeus Photonics, Inc, has invented a breakthrough family of seismic sensor systems for oil and gas exploration and production (E&P) based upon the company's unique and proprietary high-concept optical fiber technology.

The division has launched two breakthrough, turn-key fiber-optic-based sensing systems for permanent borehole installation.

The announcement was made at the International Exposition and 72nd Annual Meeting of the Society of Exploration Geophysicists (SEG) that began here yesterday.
Optical communication fibers can be transformed into extremely sensitive and precise sensors that can measure over 60 different parameters. The most common method to accomplish this is by "writing" microscopic patterns into the core of the fiber at precise, predetermined intervals.

These patterns, called Fiber Bragg Gratings (FBGs,) cause light transmitted down the fiber to be reflected back to the source. If the fiber in the area of a grating is distorted by some external force, the reflected light experiences a change in characteristics, such as color (wavelength) or phase, which may be detected at the source.
A variety of techniques exist for distorting the fiber in reaction to a stimulus, such as pressure, temperature, or sound, and after calibration, the fiber's response accurately reflects the stimulus.

What is difficult, however, is writing the microscopically-precise Fiber Bragg Gratings, at exact locations along a continuous, long fiber, without splices, or without severely weakening the fiber by stripping and recoating it, the company noted.

Sabeus said it has a unique and patented technology for accomplishing this that involves writing the Fiber Bragg Gratings directly through the protective jacket and cladding of the fiber. Some time ago, the company said it recognized that it possessed the key enabling technology for manufacturing ultra-reliable fiber-optic sensors capable of withstanding, for example, the extremes of pressure and temperature found in oil wells.
The use of sensing technology as a production tool, particularly deep inside producing oil and gas wells, is rapidly expanding as the petroleum industry experiences a shift in focus from new exploration to enhancing recovery from existing reservoirs, the company said.

Existing conventional sensing technologies predominantly require electronics packages that have to be strung deep into wells. They have proven to be difficult, unreliable, and expensive to operate, particularly due to the extremes of temperature and pressure inside a borehole that are well beyond the limits of today's electronics, Sabeus said.
But to fully exploit today's reservoirs, producers need a sensing technology that is simple to deploy, capable of being permanently installed in the well, and sophisticated enough to measure parametric changes as they occur.