Patent EA-003422-B1 (EA)
Title: Method and system for processing three-component seismic data
Inventor: GIDLOW MAURICE
IPC: G01V1/38
Filed: 1999-08-23
Abstract: 1. A method for processing seismic signals, the method comprising: reading seismic data received at a multi-component receiver; generating a mask trace as a function of the seismic data; and identifying a single type of seismic signals from the seismic data utilizing the mask trace. 2. A method, as recited in claim 1, wherein the seismic data received at the multi-component receiver includes pressure data received at a pressure sensor and velocity data received at a vertical component velocity detector. 3. A method, as recited in claim 2, wherein the seismic data received at a multi-component receiver includes velocity data received at a horizontal component velocity detector. 4. A method, as recited in claim 2, wherein the generating the mask trace further comprises: multiplying the seismic data received at the pressure sensor with the seismic data received at the vertical component velocity detector to produce a first result; identifying a positive/negative sign of the first result to produce a first binary result; and dividing the first binary result by a scaling factor to produce the mask trace. 5. A method, as recited in claim 3, wherein the generating the mask trace further comprises: multiplying the seismic data received at the pressure sensor with the seismic data received at the vertical component velocity detector to produce a first result; identifying a positive/negative sign of the first result to produce a first binary result; multiplying the seismic data received at the vertical component velocity detector with the seismic data received at the horizontal component velocity detector to produce a second result; identifying a positive/negative sign of the second result to produce a second binary result; multiplying the first binary result with the second binary result to produce a third result; and dividing the third result by a scaling factor to produce the mask trace. 6. A method, as recited in claim 5, wherein the identifying the single type of seismic signals further comprises: multiplying the horizontal component velocity data received at the horizontal component velocity detector with the mask trace whereby the single type of seismic signals representing seismic waves received at the horizontal component velocity detector. 7. A method, as recited in claim 6, further comprising displaying the single type of seismic signals remaining after the seismic waves received at the horizontal component velocity detector are extracted. 8. A method, as recited in claim 4 or 5, wherein the identifying the single of seismic signals further comprises multiplying the pressure data received at the pressure sensor with the mask trace whereby the single type of seismic signals representing seismic waves received at the pressure sensor are extracted. 9. A method, as recited in claim 7, wherein the identifying the single type of seismic signals further comprises multiplying the velocity data received at the vertical component velocity detector with the mask trace whereby the single type of seismic signals representing seismic waves received at the vertical component velocity detector are extracted. 10. A method for extraction of down-going seismic waves, the method comprising: reading seismic data received at a multi-component receiver including pressure data received at a pressure sensor and velocity data received at a vertical component velocity detector; multiplying the pressure data and the velocity data to produce a first result; identifying a positive/negative sign of the first result to produce a binary result alpha; dividing the binary result alpha by a scaling factor to produce a mask trace; and multiplying the seismic data received at one component of the multi-component receiver with the mask trace whereby the single type of seismic signals representing down-going seismic waves received at the one component of the multi-component receiver are extracted. 11. A method, as recited in claim 10, wherein the seismic data received at the one component of the multi-component receiver is the pressure data received at the pressure sensor whereby the single type of seismic signals representing down-going seismic waves received at the pressure sensor are extracted. 12. A method, as recited in claim 10, wherein the seismic data received at the one component of the multi-component receiver is the velocity data received at the vertical component velocity detector whereby the single type of seismic signals representing down-going seismic waves received at the vertical component velocity detector are extracted. 13. A method, as recited in claim 12, further comprising displaying the single type of seismic signals remaining after the down-going seismic waves received at the vertical component velocity detector are extracted. 14. A method, as recited in claim 1 or 10, further comprising generating seismic waves in a water environment for reflection from earth strata wherein the seismic data results from the seismic waves. 15. A method for extraction of up-going compressional seismic waves, the method comprising: reading seismic data received at a multi-component receiver including pressure data received at a pressure sensor, vertical component velocity data received at a vertical component velocity detector, and horizontal component velocity data received at a horizontal component velocity detector; multiplying the pressure data and the vertical component velocity data to produce a first result; identifying a positive/negative sign of the first result to produce a binary result alpha; multiplying the vertical component velocity data and the horizontal component velocity data to produce a second result; identifying a positive/negative sign of the second result to produce a binary result chi; summing the binary result alpha with a value of positive one to produce a summed binary result alpha; summing the binary result chi with a value of positive one to produce a summed binary result chi; multiplying the summed binary result alpha with the summed binary result chi to produce a third result; dividing the third result by a scaling factor of four to produce a mask trace; and multiplying the seismic data received at one component of the multi-component receiver with the mask trace wherein the method for processing extracts the single type of seismic signals representing the up-going compressional seismic waves received at the one component of the multi-component receiver. 16. A method, as recited in claim 15, wherein the seismic data received at the one component of the multi-component receiver is the pressure data received at the pressure sensor whereby the single type of seismic signals representing up-going compressional seismic waves received at the pressure sensor is extracted. 17. A method, as recited in claim 15, wherein the seismic data received at the one component of the multi-component receiver is the vertical component velocity data received at the vertical component velocity detector whereby the single type of seismic signals representing up-going compressional seismic waves received at the vertical component velocity detector is extracted. 18. A method, as recited in claim 15, wherein the seismic data received at the one component of the multi-component receiver is the horizontal component velocity data received at the horizontal component velocity detector whereby the single type of seismic signals representing up-going compressional seismic waves received at the horizontal component velocity detector. 19. A method for processing seismic signals for extraction of up-going shear seismic waves, the method comprising: reading seismic data received at a multi-component receiver including pressure data received at a pressure sensor, vertical component velocity data received at a vertical component velocity detector, and horizontal component velocity data received at a horizontal component velocity detector; multiplying the pressure data and the vertical component velocity data to produce a first result; identifying a positive/negative sign of the first result to produce a binary result alpha; multiplying the vertical component velocity data and the horizontal component velocity data to produce a second result; identifying a positive/negative sign of the second result to produce a binary result chi; summing the binary result alpha with a value of positive one to produce a summed binary result alpha; subtracting the binary result chi from a value of positive one to produce a subtracted binary result chi; multiplying the summed binary result alpha with the subtracted binary result chi to produce a third result; dividing the third result by a scaling factor of four to produce a mask trace; and multiplying the seismic data received at one component of the multi-component receiver with the mask trace wherein the method for processing extracts the single type of seismic signals representing the up-going shear seismic waves received at the one component of the multi-component receiver. 20. A method, as recited in any of claims 10, 15, 19 wherein the identifying the positive/negative sign of the first result further comprises: taking the root mean square (rms) value of the first result to produce a first rms result; setting the first rms result to a value of one; summing the first rms result set to a value of one with a value of one to produce a first positive/negative sign result; and dividing the first positive/negative sign result by a factor of two to obtain the binary result alpha. 21. A method, as recited in claim 20, wherein the identifying a positive/negative sign of the second result further comprises: taking the root mean square (rms) value of the second result to produce a second rms result; setting the second rms result to a value of one; summing the second rms result set to a value of one with a value of one to produce a second positive/negative sign result; and dividing the second positive/negative sign result by