GEOREC-S - Vertical Seismic Profile tool
Description
VSP (Vertical Seismic Profile) is the main link between time-based surface seismic imaging and depth/based well logs. It provides a high-resolution image of the structure in the vicinity of the instrumented well. One or several seismic sources on the surface are fired and recorded by the downhole receivers (GEOREC-S) positioned at different depth levels.The downhole receivers allow recording in lower noise conditions as well as recording direct arrivals and recording higher frequencies (->higher resolution) than the equivalent surface tools. The GEOREC-S is a slim downhole digital tool designed for seismic acquisition in high temperature conditions. Each GEOREC-S single level includes 3 fixed accelerometers, and have its own power supply and telemetry. Up to 48 GEOREC-S levels can be successively connected with a 7 conductors standard cable. Optionally, the accelerometers can be replaced by geophones.
Features
Mechanics:
Maximum temperature : 180°C continuously (356°F)
Maximum pressure : 1,500 bar (21,500 psi)
Maximum number of levels : 12
Diameter : 50 mm (2’’)
Total tool length : 1,450 mm (57’’)
Compatible casing diameter : 3’’ to 13’’
Locking force ratio range : 5:1 to 20:1
Maximum cable length : 6,000 m
Distance between levels : no limitations
Electronics:
Cable equalization : fully automatic
Date rates : 1.5 Mbits/s (on 6000 m cable)
Sampling rates : 0.25, 0.5, 1, 2 ms
Input noise : 0.1micro V rms
Gain settings : 24, 36, 48 dB
Dynamic range : 120 dB
Digitalization : 24 bits
Sensors:
Fixed Geophones : Omni 2400 15Hz
Accelerometers : 7703A - 1000
Benefits
* Working temperature up to 180°C continuously (356°F), without active cooling.
* Working pressure up to 1,500 bar (21,500 psi)
* Independent power supply and telemetry - on each level -preventing from full breakdown
