CLO Processing

CLO (continuous long offset) is a PGS proprietary technology which enables the imaging of very long offsets by using a standard multi-streamer configuration combined with a second source vessel. The CLO approach ensures operational efficiency, stability, safety, and minimal infill requirements.

This image demonstrates how the Source-streamer vessel and Source-only vessel are arranged, and their effective subsurface illumination.

These two diagrams illustrate one of CLO’s advantages in achieving more uniform subsurface coverage due to the use of shorter streamers. The display on the left is the subsurface fold coverage from a long streamer configuration, and the display on the right is that which is achieved using CLO.

This image was made by placing two shot gathers with coincident source positions side-by-side to simulate what would have been obtained using a long streamer.

Processing of CLO data volumes

The actual processing of CLO data volumes is fairly straightforward, and has been done successfully within PGS for over a decade. 

The following are images extracted from some of the 3D volumes that have been completed to date.  The basic processing flow following CLO acquisition consisted of a deterministic method utilizing wavelet shaping to zero phase, followed by Q compensation.  Also included in the flows were radon and MDA to suppress multiples.

The first section utilized a DMO-poststack migration to complete the image.  The second was completed utilizing PGS’s TAPSTM (true amplitude pre-stack time migration) algorithm.