Multi-component downhole seismic array GStreamer is a cost effective solution for 3C borehole engineering and environmental surveys such as VSP and crosswell tomography.
We developed an easy-to-operate downhole tool with robust deployment and clamping system. Deployment is performed by placing multi-level 3C geophone array into the borehole without need of additional depressors. Once the borehole array is placed in the well, all units are clamped simultaneously by simply pulling the secure wire, bringing array in operational mode.
Each geophone pod housing contains 3 component sensors combined orthogonally with natural frequency of 12.5 Hz. GStreamer array configuration is quite flexible – it can be manufactured with up to 8 levels, interval between the tools is on the customer’s choice.
Combination of GStreamer array, Jack energy source and Shock borehole source provides modern acquisition setup for compressional (P) and shear (S) waves generation and registration. Registered wavefields are used to determine P- and S-wave velocity profiles which are typically used for Poisson’s ratio and other elastic modulus estimation, required for various engineering applications, such as foundation studies, soil and rock mechanics and earthquake engineering.
The geophone array can be supplied on a reel with slip ring, which allows to leave the equipment plugged into it while winding and unwinding the cable.
VSP and crosshole data processing requires efficient and sophisticated processing flow. RadExPro seismic software provides all necessary algorithms for multi-component data processing – hodogram analysis, 2C/3C component orientation, wavefield separation, velocity modelling, corridor stacking and well tie to reflection seismic data. Examples of data, acquired by GStreamer and processed in RadExPro software are shown below.
Geodevice offers equipment for borehole seismic surveys as well as acquisition, education and processing services.
|Number of modules in array||1 – 8 pc|
|Number of channels in module||3 pc|
|Compensation coupled geophones||yes|
|Natural frequency of geophones||12.5 Hz|
|Maximum operating pressure||15 atm.|
|Interval between modules in array||1 – 10 m|
|Maximum diameter of module||60 mm|
|Borehole diameter range||70 – 150 mm|
|Clamping force range||1:7 – 1:11|
|Remote snapping of springs||yes|
|Operation without plummet in the well||yes|
|Compatible with linear seismic stations||yes|
Borehole sources and energy sources
Reels and Synchronizes
ZondST2d — 2D seismotomography interpretation (refracted waves)
ZondST3d — 3D seismotomography interpretation (refracted waves)