Seismic Telemetric System XZone

The XZone - first Russian manufactured telemetric systems complex made by Russian company SI Technology based in Gelendzhik.
XZone, a new series of digital telemetry systems, includes three complex techniques, namely the Bottom Fish technique for marine acquisition, Marsh Line technique for seismic survey of transitional zones and Fly Lander for seismic survey onshore.
Each seismic survey technique is based on a certain type of field electronic module, which performs functions of a receiver of seismic electronic signals, carries out 24-bit analogue-to-digital conversion, digitally preprocesses seismic data, compacts seismic information into data packets to be transferred via telemetry communication lines, monitors the quality of seismic signal reception and controls the operation of electronic equipment incorporated into the electronic module.
XZone features functional flexibility, which permits a quick upgrade of both the on-board station and an in-field module either to accommodate the latest inventions of the company, or to meet specific requirements under the customer's order.
Most of the tasks on processing seismic signals, testing and telemetry communication are realized in the form of special software installed on electronic modules.
The configuration of the system allows the on-board station during start-up to replace any software installed on an in-field module. For this purpose, the user should just copy a file with updated software into a certain catalogue of the on-board station.
At start-up, the station itself detects the file with an updated version of the software to download it within five seconds on in-field electronic modules via the same telemetry communication lines used for acquisition of seismic data.

XZone Bottom Fish Advantages

While developing a bay digital cable for the XZone-Bottom Fish seismic system, SI Technologies experts set themselves the target to create a functionally comprehensive marine seismic telemetry system which would be simple to use but with maximum dependable. Specifically designed for 2D or 3D seismic surveys on shallow depths (down to 30 m), this system includes a filled with oil digital cable assembled of 75 meter long telemetry cable sections instrumented with built-in piezometers i.e. hydrophones and electronic modules. Actually, this is a regular design drag cable towed by ship.
The cable has a uniform structure with all its components located inside the telemetry cable sections. Compared to other similar systems, Bottom Fish features half as many titanium couplings to ensure higher reliability of the system as a whole. To carry out seismic survey on linear traverse in the start/stop operation mode, an additional 100 m long cable-adapter is switched to the active section of the main cable.
Bottom Fish is very well adapted to different environment conditions. Owing to the specific design, the equipment can be used in the tough environment of shallow waters and extreme shallow depths when towed along sandy and shelly seafloor or riverbed through water-plans or in silt. A small diameter of the cable (47 mm OD) makes it possible to use small weight research vessels equipped with small winch drums and 6,000 m long drag cables for as many channels as 960.
Bottom Fish uses Russian made hydrophones, whose performance matches imports. Field trials of Bottom Fish system was carried out in the White Sea on board "Professor Kurentsov" scientific research vessel. Specialists from the Marin Arctic Geological Expedition (MAGE) have received from the vessel an extensive volume of 2D seismic data.

Shallow waters and transitional zones research

Marsh Line, an XZone series seismic survey telemetry system, was designed especially for seismic surveys in transitional and difficult-to-reach zones, exploration of which is especially labor-intensive. These zones include river deltas, shallow waters, swamps and flooded areas.
The main feature of the Marsh Line system is a weight bearing cable-truss designed to be towed a river bed or dragged on-shore. A prototype designed by Sea Technologies is in essence a seismic digital cable made up of 100 to 200 meter-long cable sections connected to each other by means of steel heavy-duty waterproof couplings. Like the Bottom Fish version, each section of Marsh Line cable houses removable seismic signal registration modules with built-in seismic sensors (i.e.) self-aligning geophones and hydrophones. The system could be successfully used both for transitional zones, shallow waters, on-shore, sandy and saline land, snow and ice covered areas.
Similar to Bottom Fish, Marsh Line consists of an onboard unit, which includes a central seismic data acquisition system (CSDAS) with a built-in power source, docking devices and in-sea peripheral components.
The main purpose of CSDAS is to collect, amass and keep seismic information, preprocess data, calibrate and adjust the system, monitor its operation, provide connection with steering systems and synchronize blasts.
The first arrangement of cable along the profile in question is made either from a vessel or a pontoon moving at a rate of two knots, or from a cross-country vehicle moving at a rate of 5 km/h, both on sand bars and on-shore, by dragging the cable along the profile.
Owing to a cylindrical shape of the electronic module housing that ensures low friction resistance, the cable can be easily towed both along reservoir beds and on-shore. The system can be easily transported a required distance by a vehicle, and is ready to work immediately after stopping.
Attached to a steel cable-truss, the system keeps its linearity even in very rugged country and actually does not change its position on the riverbed under the influence of undercurrents. Horizontal coordinates of the receivers can be easily fixed at the front and at the tail of the streamer.
To determine coordinates of the modules under water, the Marsh Line system can be upgraded with an additional built-in hydro-acoustic navigation system, which employs special hydro-acoustic excitation sources.
The stiffness of Marsh Line cable make-up, even if stretched along a profile, allows exclusion of transponders (i.e.) position sensors which are always used in telemetry systems with flexible cable. In Mash Line, it is quite enough to fix only coordinates of the cable's tail. Locating the geophones inside the waterproof and massive cylindrical metal modules gives additional protection against noises produced by sea surface waves, during the registration of seismic signals.
In March 2003, in the Khanty-Mansiysk region XZone Marsh Line and Sercel SN380 telemetry systems were tested in parallel to compare their performance. The same 1,4 km long reference profile was scanned using both of the systems. Data registered by the Russian system proved comparable with that obtained by the similar foreign-made complex. Specialists underline Marsh Line's high technological effectiveness. Compared to conventional cable systems, Marsh Line has a real advantage in that fewer personnel are needed to arrange the sensors on a profile because all the sensors of the system are made up into a single line. To start a seismic survey, it is enough to drag the cable along the profile in question using a tow vehicle. You can also rearrange the system without having to pick up the sensors every time - just drag the cable to the right places at specified intervals.

WGP Seismic Ltd. has been commissioned by the manufacturers of this new system – SI Technology based in Gelendzhik, on the Russian Black Sea coast – to undertake tests of the streamer sensitivity. This work has been done in 2005 at the Teledyne facility in Gloucester.
Results are still being analysed but look very encouraging.
The Bottomfish system has been used in Russia but is new to the international industry, so SI were keen to have the accuracy of the streamer validated before the beginning of the MAGE project in India later 2005.