Tawassul A. Khan, E. Lynard Olsen
Three main requirements in the design of a field system help to improve seismic field productivity: (1) fast execution time, (2) simultaneous execution of several unrelated tasks, and (3) capability of multi-function recording. Multi-function recording relates to the various options available that provide multiple choices of using seismic sources, receivers, arrays, data transmission, and data-processing methods. These features allow one to use the recording system to the best advantage under changing geologic and field conditions. Faster execution time is necessary when dealing with large numbers of channels and high sample rates. Simultaneous execution of data transmission, data processing, monitoring, and quality control are needed for a realtime recording system. Multi-function recording provides capabilities like multi-functions (receiver, source, array, weight, correlate, etc) that have been specifically developed to provide considerable improvements in the field production.
Using the multi-receiver method, one can record two, three, or four times the data corresponding to the ground stations in relation to the number of data channels being transmitted to the system recorder. For example, using a data encoding technique, geophone outputs from 240 or 360 ground stations can be transmitted using only 120 data channels. Realtime decoding in the system recorder separates the data belonging to each ground station and outputs the original 240 or 360 seismic traces to the final tape. Similarly, the Multisource method uses different source encoding techniques that can be decoded in real time to provide higher CDP fold or multiple line recording.
AAPG Search and Discovery Article #91035©1988 AAPG-SEPM-SEG Pacific Sections and SPWLA Annual Convention, Santa Barbara, California, 17-19 April 1988.