Apparatus and method for acquiring seismic data

• US 5,623,455 A
• Filed: 05/25/1995
• Issued: 04/22/1997
• Est. Priority Date: 05/25/1995
• Status: Expired due to Term

• Current Assignee: WesternGeco LLC
• Original Assignee: Western Atlas International Incorporated (Northrop Grumman Corporation)
• Inventors: Norris, Michael W.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/450,199
• Time in Patent Office: 698 Days
• Field of Search: 367/13, 367/55, 367/59, 367/56, 367/76
• US Class Current: 367/76
• CPC Class Codes: G01V 1/20 Arrangements of receiving elements, e.g. geophone pattern
• CPC Class Codes: G01V 1/22 Transmitting seismic signals to recording or processing apparatus

Abstract

A seismic data acquisition system utilizing a plurality of remote units, each remote unit being coupled to a plurality of receivers placed spaced apart on the earth'"'"'s surface is provided. The remote units acquire seismic data from their associated receivers in response to a seismic shock wave induced at a selected point on the earth and transmit the acquired seismic data to a recorder over a separate channel associated with each receiver. A signature device located at a known receiver location transmits a data sequence containing an embedded time-invariant code that is unique to the signature device to the recorded during the recording cycle. The signature device data sequence and its location are pre-recorded in the recorder. The recorder utilizing the stored data sequence and the data sequence transmitted by the signature device during the recording cycle to map the seismic data channels corresponding to the locations of their associated receivers. The invention for acquiring seismic data contains the steps of: (a) acquiring seismic data from a plurality of seismic sensors placed spaced apart on the earth; (b) transmitting the seismic data acquired from the seismic sensors to the recorder over a separate channel associated with each receiver; (c) transmitting a data sequence having an embedded time-invariant code from a signature device located at a sensor location; and (d) utilizing the data sequence transmitted by the signature device to map the seismic data associated with each channel corresponding to the location of its seismic sensors.

Claims

1. A seismic data acquisition system, comprising:

a remote unit coupled to a plurality of receivers placed spaced apart at known locations, said remote unit acquiring seismic data from the receivers over a separate data channel associated with each such receiver in response to an induced shock wave into the earth, said remote unit transmitting the acquired seismic data to a recorder during a data recording cycle;

a signature device located at a known location for transmitting a data sequence having a time-invariant code to the recorder during the recording cycle; and

said recorder utilizing the data sequence to map the seismic data associated with each said data channel corresponding to the location of its associated receiver.

2. The system of claim 1, wherein the seismic data is recorded on a storage media.

3. The system of claim 1, wherein the data sequence contains a preamble that signifies the beginning of the data sequence and a postamble that signifies the end of the data sequence.

4. The system of claim 3, wherein the data sequence contains data which identifies the location of the signature device.

5. The system of claim 3, wherein the data sequence contains data that identifies the time and day when the data sequence is transmitted.

6. A seismic data acquisition system, comprising:

a plurality of remote units, each said remote unit being associated with a separate plurality of receivers placed spaced apart at known locations on the earth'"'"'s surface, said remote units acquiring seismic data from their associated receivers in response to a seismic shock wave induced into the earth at a predetermined location, said remote units transmitting the acquired seismic data to a recorder during a data recording cycle;

a signature device located at a known location for transmitting a data sequence having a time-invariant code to the recorder during the recording cycle; and

said recorder utilizing the data sequence to map the seismic data received from the receivers corresponding the location of their associated receivers.

7. The system of claim 6, wherein the data sequence contains a preamble that signifies the beginning of the data sequence, a postamble that signifies the end of the data sequence and a data sequence that identifies the location of the signature device.

8. The system of claim 6, wherein the recorder contains a computer which has stored therein the data sequence of the signature device and utilizes both the stored data sequence and the data sequence received from the signature device for mapping the seismic data corresponding to the locations of the receivers.

9. A seismic data acquisition system, comprising:

a plurality of remote units, each said remote unit in the plurality of remote units coupled to a plurality of associated receivers placed spaced apart at known locations within a desired region on the earth'"'"'s surface, said remote units acquiring seismic data from their associated receivers in response to a seismic shock wave generated by a source placed at a predetermined location on the earth, said remote units transmitting the acquired seismic data to a data acquisition unit during a data recording cycle;

a plurality of signature devices, each said signature device located at a separate known location within the desired region, each said signature device transmitting a data sequence having an embedded time-invariant code which is unique to such signature device to the data acquisition unit during the recording cycle;

a computer coupled to the data acquisition unit having stored therein the data sequences for the signature devices, said computer utilizing the stored data sequences for the signature devices and the data sequences received from the signature devices to map the seismic data received from the remote units to the locations of their corresponding receivers.

10. A seismic data recording system comprising:

(a) a plurality of remote data acquisition units deployed within a desired region and spaced apart according to a desired grid spacing, each said remote data acquisition unit coupled to a receiver station having known geographic location within the desired region to acquire at least one channel of seismic data from the receiver coupled to such remote data acquisition unit;

(b) a recorder for receiving the seismic data from the remote data acquisition units; and

(c) a signature device placed at a known geographic location within the desired region for transmitting a data sequence having an embedded time-invariant code that is unique to the signature device to the recorder, said recorder utilizing the data sequence to map the seismic data received corresponding to the known geographic locations of their associated receivers.

11. The system of claim 10, wherein the unique data sequence contains a preamble that signifies the beginning of the unique data sequence and a postamble that signifies the end of the unique data sequence.

12. The system of claim 11, wherein the unique data sequence contains data which identifies the location of the signature.

13. The seismic data recording system according to claim 10, wherein the unique data sequence is pre-recorded in the recorder and the recorder utilizes the prerecorded unique data sequence and the unique data sequence received from the signature device to record the seismic data received from the remote data acquisition units corresponding to the known geographic locations of the receivers.

14. A method of acquiring seismic data, comprising the steps of:

(a) acquiring seismic data from a plurality of seismic sensors placed spaced apart at known locations within a desired region;

(b) transmitting the seismic data acquired from the seismic sensors to a recorder; and

(c) transmitting a data sequence containing an embedded code from a signature device placed at a known location within the region to the recorder, said recorder utilizing the data sequence received from the signature device to map the seismic data received from the seismic sensors corresponding to their known locations.

15. The method of acquiring seismic data as specified in claim 14, wherein the data sequence further contains information about the location of the signature device.

16. The method of acquiring seismic data as specified in claim 14, wherein the data sequence further contains a preamble defining the beginning of the data sequence and a postamble defining the end of the data sequence.

17. A method of acquiring seismic data, comprising the steps of:

(a) acquiring seismic data from a plurality of seismic sensors placed spaced apart at known locations on the earth'"'"'s surface according to a predetermined grid pattern within a desired region;

(b) transmitting the seismic data acquired from the seismic sensors to a recorder having a computer;

(c) transmitting a data sequence from a signature device placed at a known location within the region to the recorder, said data sequence containing an embedded time-invariant code that is unique to the signature device; and

(d) storing the data sequence and the location of the signature device in a memory associated with the recorder; and

(e) mapping the seismic data received from the seismic sensors corresponding to their known locations by utilizing the data sequence stored in the memory and the data sequence received from the signature device.