Geospace Installs Largest Permanent Subsea Seismic System

OYO Geospace has installed the industry's largest permanent subsea seismic system. The system consists of 2,504 multi-component stations with a total of 10,016 channels. The system is installed in the Valhall Field located in the Norwegian sector of the North Sea in 70 meters of water. BP's Norwegian subsidiary, BP Norge, operates the field in partnership with divisions of Shell, Amerada Hess and Total. More than 90 miles of armored cables consisting of the sensor and digitizing system were trenched approximately one (1) meter below the ocean floor and cabled to the production platform. The data is gathered and temporarily stored on the platform. Data is then available for transmission via a fiber optic transmission cable directly into the processing office onshore or, conventionally through stored media. In addition to gathering seismic data, the system also measures tidal action and reservoir subsidence at the rig site.

The project was a joint collaboration between BP and Geospace Engineering Resources International (GERI), a division of OYO Geospace. The project was more than two years in design and construction. Rigorous sea trials were conducted prior to installation to insure a successful installation. The system was designed and manufactured in-house by GERI and the manufacturing divisions of OYO Geospace in Houston, Texas.

Gary D. Owens, Chairman, President and CEO of OYO Geospace, said, "This marks the beginning of a new application for the seismic method in which the industry can monitor changes in the reservoir during production of the field. Such information can lead to an increase in extracted hydrocarbons. The system increases knowledge of the reservoir by monitoring production caused changes. Understanding the changes in a field's characteristics allows the engineers to utilize the best options available to sustain and increase the productive life of a field."

Owens continued, "We are hopeful that the success of this project will lead to future projects in other fields. We are aware of other potential fields in need of this technology. The time-lapse seismic technique is one of the most sought after new tools for managing the reservoir. The permanent seismic system solution offers significant advantages over retrievable systems in many situations. It is these particular reservoir situations that hold the best opportunities for us in the future to build on what we have learned in this project."

The system technology of GERI is also in use in the deep waters of the North Sea in the form of retrievable subsea seismic acquisition systems as well as employed in the company's suite of borehole seismic systems. Both system types were designed by GERI and manufactured by the manufacturing division of OYO Geospace. They are currently used in North America, China, Europe and the Middle East.