V.D. ZHEREBTSOV JSC Sevmomeftegeofizika, Russia

Subject of consideration - Making the high-tech measuring system for searching and monitoring oil-and-gas field.

The seismic fiber-optic measuring systems (FOMS) are the qualitative-new systems for searching and monitoring offshore oil-and-gas studies. FOMS are founded on phase or frequency optical principle of the measurement. These systems allow to get the more qualitative geology-geophysical information, reduce the cost of the exploratory work, enlarge the period of measuring device usage in contrast with traditional system, which are based on electromagnetic principle of the measurement.

Using the fiber measuring technology for seismic allows to raise the measurement resolution. Due to the absence of the electromagnetic interference influence the FOMS are possible to be used in industrial zones as well as for the increasing of the oil-and-gas fields search. The Measurement of the seismic field is carried out in discrete area on frequency 1015 Hz. (the length of the optical waves 1 = 0.8-1.68 mm). This simplifies the receiving measuring channel in which the alias effect is practically absent during the measurement of seismic fluctuations on frequencies F=l Hz - 500 Hz. At the same time we can note the decreasing of the reflected and multiple waves influence on the seismic measurement that promotes increasing of the quality processing seismic data.

In given report are considered the principles of the development FOMS on the base of the fiber-optic hydrophone and geophone designed in 2000-2002 by JSC "Sevmomefiegeofizika" and measuring phase optical seismic channel, developed on the using the semiconductor laser.

The hydrophone is developed on the base of interferometer Mach-Zehnder. During laboratory tests the given hydrophone has shown the increasing of sensitivity in 7-8 times in contrast with piezoceramics hydrophones. In this geophone is used the interferometer Fabry-Perot. The laboratory test has shown optical sensitivity of 3x10-3 nm that exceeds the features of the known geophones.

The measuring system is built on principle of the module hierarchical structure, having high reliability capacity and possibility of the expansion.

The authors of the report have some patents on realization of the systems of the present directions, as well as the international grand received and executed.

ARCTIC SHELF OIL AND GAS CONFERENCE 2004