All-optical sensor

US Sensor Systems, based in Northridge, California, has developed a small, fibre-optic geophone for oilfield seismic exploration and production.

The patent-pending, all-optical, omni-directional sensor requires no electrical power and can provide a clear picture of untapped underground oil or gas.

Unlike traditional electronic detection systems that rely on a distributed network of point sensors, every inch of the fibre-optic cable used in the geophone is acoustically sensitive, providing a much wider area of coverage at a lower cost.

In addition, since the sensing portion of the system is all optical, there are no in-situ electronics - a typical failure point for traditional systems.

The sensor has been developed to meet the demanding requirements for permanent 4D seismic monitoring and is being evaluated by one of the world’s largest oil companies for a downhole monitoring application.

'However, the sensor can also be used for surface seismic [land] or marine seismic [underwater],' stated Jim Andersen, chief executive officer of US Sensor Systems.

'It will enable producers to extract more oil from existing reservoirs by providing repeatable, higher-resolution images of their oil-and-gas fields, which most experts agree are needed to meet the world’s increasing energy demands,' he added.

'For more than 10 years, the US Department of Energy, every major oil company and all of the oilfield service companies have been looking for a small, reliable, low-cost sensing system for permanent surface and downhole monitoring applications. Sensor Systems' sensor appears to be the best solution I have seen,' said Dr Björn Paulsson, one of the world’s foremost oilfield geophysicists and chief executive officer of Paulsson.