The distributed nature of the measurement means that each point along the fibre is sampled simultaneously for each source initiation, dramatically reducing the operating time required for a conventional survey and significantly increasing the achievable wellbore coverage for moving source surveys.
Using our SeiBer™ acquisition software, the iDAS can be used to trigger the source using a conventional controller, alternatively the iDAS can passively record the acoustic field continuously. In passive mode the iDAS performs in a sample-perfect manner ensuring that no samples are lost in the transition between data files and that zero-drift occurs relative to GPS time used to timestamp all data. Multi-well acquisition is made possible by synchronising multiple iDAS systems.
Whether triggered or in passive acquisition mode the iDAS seismic platform can generate SEGY data files in the field when geometry information and source navigation and timing information is made available.
When the optical fibre cable is permanently installed in the well, seismic acquisition can be performed without the need for well intervention and without stopping production, therefore offering significant savings to the operator and opening acquisition opportunities in existing wells otherwise not accessible to conventional borehole seismic techniques. A permanently installed cable also offers the ideal platform for time lapse seismic where channel depths are consistent from survey to survey.