Seismic Reflection Acquisition Overview
Seismic reflection can be carried out with a wide range of configurations. Optimum imagery of a particular target requires the correct choice of energy source, geophones, recording instrumentation and recording geometry.
With over 25 years of field experience throughout the Asia Pacific region, Velseis prides itself on providing an integrated acquisition service specifically tailored to the needs of each client.
This integrated survey design must consider not only the geophysical requirements, but also logistical, climatic, environmental and safety issues.
Velseis can provide field crews customised for any project, based on the energy source, location, and survey parameters. Experienced observers are responsible for data acquisition and field operations, and are assisted by crew managers responsible for crew safety and logistics.
In most cases, Sercel 428 or 408 recording systems are used. In addition, the VEGAS system developed by Velseis’ R&D division is employed for specialised projects. Designed specifically for Velseis’ operations, this system is highly configurable, with a range of infield software control to optimise acquisition efficiency whilst maintaining data quality.
Velseis can provide various energy sources:
- Vibroseis – Velseis have six IVI Envirovibe buggies, and three Inova Univib buggies. The IVI Envirovibes are light vibroseis buggies, which are very manoeuvrable, environmentally friendly (low impact), and easily transported. The Inova Univibs are slightly larger units which can be fitted with weights for additional force during sweeps. The Vibroseis technique is well suited to projects requiring an efficient and cost-effective method of acquisition.
- Dynamite – As noted above, Velseis is highly experienced in the recording of dynamite surveys, with licensed and experienced shot firers on staff. Dynamite surveys are suitable for projects where the highest possible resolution is a priority.
- Mini-SOSIE – In areas with particular environmental or access restrictions, Mini-SOSIE provides a source which is geophysically competitive with Vibroseis. The technique uses a conventional road compactor as the source, and provides a very low impact operation. With smaller crews required, this technique can be well suited to smaller projects with shallower targets. Mini-SOSIE is also effective as an alternative source for areas of a 3D Vibroseis survey where the Vibroseis buggies are not able to access due to environmental or other restrictions.