In order to reduce the acquisition time of well seismic data, and thus downtime well costs, most receiver systems used in the petroleum industry are array tools including a master unit and satellite tools. These permit the simultaneous recording at several depths and are particularly useful in operations of seismic walkaways. The master tool includes the telemetry system, which provides the transfer of data from the bottom of the hole to the surface. Each of the tools includes an anchoring system and a seismic module. We will present two examples among systems available on the market.

The first example illustrates the characteristics of Schlumberger's receiver system called "Combinable Seismic Imager" (CSI). A schematic of the master tool is shown in the left part of the figure. In the seismic module, the geophones are mounted on gimbals and decoupled from the tool body in order to obtain a better quality of the seismic signal. The right part of the figure shows the classical configuration used with the CSI system. (from Schlumberger document)

In Compagnie Générale de Géophysique's SST 500 system, illustrated in the second example, each satellite tool is equipped with 3-component geophones and a hydrophone as an option. Seismic acquisition can be done with a maximum of 16 satellite tools with 3-component geophones, or 12 satellite tools with 3-component geophones and a hydrophone. This types of tools minimize well downtimes for seismic walkaway operations.

SST 500 tool
(from CGG document)