METHOD AND APPARATUS FOR SEISMIC SIGNAL PATTERN DISCRIMINATION

• US 3,652,980 A
• Filed: 08/11/1969
• Issued: 03/28/1972
• Est. Priority Date: 08/11/1969
• Status: Expired due to Term

• Current Assignee: Pierre L. Goupillaud
• Original Assignee: Pierre L. Goupillaud
• Inventors: Goupillaud, Pierre L.
• Primary Examiner(s): Bennett, Jr., Rodney D.
• Assistant Examiner(s): Moskowitz, N.
• Application Number:
  US04/848,777
• Time in Patent Office: 960 Days
• Field of Search: 340/15.5,15.5F,15.5AF,15.5GC,15.5CC,15.5SC
• US Class Current: 367/46
• CPC Class Codes: G01V 1/28 Processing seismic data, e.g. for interpretation or for event detection G01V1/48 takes precedence
• CPC Class Codes: G01V 2210/20 Trace signal pre-filtering to select, remove or transform specific events or signal components, i.e. trace-in/trace-out
• CPC Class Codes: G01V 2210/56 De-ghosting; Reverberation compensation

Abstract

A method for extracting predetermined types of seismic data from an overall composite of seismic information, the method consisting of constructing an ideal filter for each of selected primary, multiple and/or interference components of a seismic tract group, such filter construction being carried out by determining the pseudoinverse or generalized inverse of a polynomial matrix as determined for the particular seismic traces to be examined, with application of the polynomial matrix for preadjustment of a multichannel pattern discriminating filter which, when energized by the input seismic traces under examination, will produce separately the requisite primary, multiple and interference outputs which represent the respective components present. Apparatus for carrying out the method may consist of plural channels of time domain filters connected in series with a weighting device for convolving respective plural seismic traces; each of the convolution filters is adjusted to function at predetermined times and amplitudes in accordance with the matrix function or operator determined for primary, multiple and interference trace functions of a particular group of seismic traces.

Claims

2. A multi-trace pattern discriminating filter as set forth in claim 1 wherein said output means comprises:

time domain filter means for selectively receiving summed output from one of said summation means to generate a plurality of time displaced outputs each delayed by a preselected different time; and

spiking weighting means receiving each of said time displaced outputs to effect preselected polarization and attenuation in accordance with time delay position, and to sum all displaced and attenuated outputs to provide a time analog output signal indicative of a selected component of reflection seismic energy.

3. A multi-trace pattern discriminating filter as set forth in claim 1 which is further characterized in that:

each timE domain filter of said first pattern filter delays each respective one of the plurality of time delayed outputs by the same increment;

each time domain filter of said second pattern filter delays each respective one of the plurality of time delayed outputs by the same increment; and

each time domain filter of said third pattern filter delays each respective one of the plurality of time delayed outputs by the same increment.

4. A multi-trace pattern discriminating filter as set forth in claim 1 wherein each of said weighting networks comprises:

a plurality of attenuators each receiving a selected time delayed output to generate an attenuated output, each attenuator adjusting a respective time delayed output to a selected magnitude which is said function of a characteristic operator for a selected component of the particular one of said plural traces which were applied to the respective time domain filter providing said time delayed outputs; and

attenuator summing means receiving attenuated outputs from each of said plurality of attenuators to provide said summed output.

5. A multi-trace pattern descriminating filter as set forth in claim 4 wherein said output means comprises:

time domain filter means for selectively receiving summed output from one of said summation means to generate a plurality of time displaced outputs each delayed by a preselected different time; and

spiking weighting means receiving each of said time displayed outputs to effect preselected polarization and attenuation in accordance with time delay position, and to sum all displaced and attenuated outputs to provide a time analog output signal indicative of a selected component of reflection seismic energy.

6. A multi-trace pattern discriminating filter as set forth in claim 1 wherein said output means comprises:

selective input means for receiving a selected one of said time analog signal outputs;

operational amplifier means receiving said time analog signal output for amplification to provide an output voltage, said amplifier means including a feedback input;

a delay line having plural, time displaced outputs and a signal output and receiving said output voltage at an input;

variable attenuating means each connected between a different one of said time displaced delay line outputs and said feedback input, said attenuating means for each time displaced output being set in accordance with a preset time analog operator;

an output device receiving said delay line signal output for representation as a selected energy component within said multiple traces of seismic data.

7. Apparatus for processing multi-trace seismic information by effecting exclusive extraction of plural data indications each having predetermined energy characteristics, comprising:

means for dividing said multi-trace seismic information into plural, parallel groups of plural trace inputs;

first convolution means receiving a first group of said plural trace inputs for separately convolving each input with a trace operator representative of time and amplitude characteristics for energy traveling a first selected path to generate a respective convolution output for each of said trace inputs;

second convolution means receiving a second parallel group of said plural trace inputs for separately convolving each input with a second predetermined trace operator representative of time and amplitude characteristics for energy traveling at a second selected path which is different from said first selected path to generate a respective convolution output for each of said trace inputs;

third convolution means receiving a third parallel group of said plural trace inputs for separately convolving each input with a third predetermined trace operator representative of time and amplitude characteristics for energy traveling a third selected path which is different from said first and second selected paths to generate a respective convolution output for each of said Trace inputs; and

a plurality of summation means for separately summing the plural convolution outputs from each of said first, second and third convolution means to generate first and second generalized indications of trace energies along said first, second and third reflection paths.

8. A method for processing multi-trace seismic information by effecting exclusive extraction of plural data indications each having predetermined energy characteristics, comprising the steps of:

dividing said multi-trace seismic information into plural parallel groups of multi-trace inputs;

convolving each trace of each group with a predetermined operator which is representative of time and amplitude of energy traveling a selected path as determined by the pseudoinverse matrix function for the selected path, the respective operators of a first group representing primary reflection for each trace, the respective operators for a second group representing multiple reflection for each trace;

separately summing convolved traces of each group to provide a group convolution trace representing reflection characteristics for selected seismic energy forms traveling selected paths.

9. A method for processing multi-trace seismic information by effecting exclusive extraction of plural data indications each having predetermined energy characteristics, comprising the steps of:

dividing said multi-trace seismic information into plural, parallel channels;

convolving each input of multi-trace information from first and second channels with respect to first and second predetermined time analog operators representative of primary and multiple components of reflection energy as determined by the pseudoinverse matrix function for the respective energy components to produce first and second output representations neither of which contains any indication of energy common to the other;

recompressing said first and second output representations to obtain an indication of the primary and multiple components of energy, respectively.

10. A method as set forth in claim 9 which is further characterized to include the steps of:

convolving each input of multi-trace information from a third channel with a respective third predetermined time analog operator representative of an interference component of reflection energy to produce a third output representation containing no indication of energy common to that of said first and second output representations;

recompressing said third output representation to obtain an indication of the interference component of energy within said multi-trace information.