Advanced in-sea source controller and borehole seismic QC
As petroleum exploration advances to deeper wells and more complex formations, highly predictable and consistent seismic sources are required to deliver superior-quality signals. Schlumberger has met the challenge by introducing TRISOR seismic source controller to the Q-Borehole integrated borehole seismic system, resulting in improved safety, data quality, and efficiency. Based on the WesternGeco TRISOR marine seismic source controller, the controller for borehole seismic operations provides the same stable, noise-free digital signatures and advanced QC.
The in-sea electronics that control each gun are connected by a proprietary ruggedized Ethernet cable for digital communication with the VSI Versatile Seismic Imager surface acquisition system. This configuration avoids the corruption that may occur to analog signals carried on conventional umbilicals. The direct interface to the VSI acquisition software supports monitoring surface and downhole operations from one integrated QC panel,which eliminates shot number mismatches and ensures accurate recording and reporting of source positioning and downhole data.
TRISOR system accuracy is ±0.5 ms or better, with typical gun synchronization values of ±0.1 ms. Continuous monitoring of the QC data significantly reduces the possibility of continuing a survey if there is an equipment malfunction. Safety is also intrinsic to TRISOR operations because the guns cannot be fired while out of the water, and the controller defaults to automatic power-down mode if the cable is disconnected or leakage detected.
Depth and pressure sensors at the source are used to log the source depth and pressure with each shot. Firing is allowed only within the specified depth range. Pressure parameters are similarly set for firing to prevent source signature variations caused by variations in source pressure.
The calibrated near-field hydrophone integrated with the TRISOR system provides a higher quality signal than conventional hydrophones that improves source-signature deconvolution. The digital hydrophone data are recorded simultaneously with the VSI downhole data.
Applications
- Borehole seismic operations that require a high-quality,consistent source signature with calibrated amplitude
- Shot-by-shot source signature deconvolution
- Effective Q-factor derivation from source to downhole sensor by using the near-field signature to generate
Benefits
- Intrinsically safer operations
-
Optimized source synchronization with stable, noise-free digital signatures
Features
- Gun pressure and depth sensors for advanced QC
- No signal contamination from in-sea digitization
- Fast automatic tuning and offline setup
- GPS time stamping and synchronized shot firing
- Calibrated hydrophone
- Full integration with navigation
Request More Information
|