US4635238A
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Data processing method for correcting P and S wave seismic traces
Assignee: Phillips Petroleum Co
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Filing: 1984-09-12
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Granted: 1987-01-06
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Expires: 2004-09-12
Abstract
Abstract A method of processing seismic data enables correlation of P and S-wave seismic traces. First, P and S-waves are transmitted into the subsurface. The two-way vertical travel times are then measured for each wave to different depths so as to yield two sets of time-depths pairs. Mathematical functions relating two-way vertical travel time, T s or T p , and depth are fitted to each set of time-depth pairs. These functions are combined to yield an expression relating T s and T p . This expression may be utilized to rescale one of the traces to yield correlated P and S-wave traces.
Inventors
- 👤 Joseph G. Gallagher
- 👤 Kay D. Wyatt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:29
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/28; G01V1/284; G01V1/40; G01V1/42; G01V2210/00; G01V2210/10; G01V2210/16; G01V2210/161
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
190 words
A method of processing seismic data enabling the correlation of P and S-wave wiggle traces comprising the steps of: (a) transmitting a P-wave and an S-wave into the subsurface of the earth; (b) measuring the two-way vertical travel times of the S-wave to different depths in the subsurface, thereby yielding a set of S-wave time-depth pairs wherein each time-depth pair includes a depth value z and a corresponding S-wave two-way vertical travel time value T s ; (c) measuring the two-way vertical travel times of the P-wave to different depths in the subsurface, thereby yielding a set of P-wave time-depth pairs, wherein each time-depth pair includes a depth value z and a corresponding P-wave two way vertical travel time value Tp; (d) fitting a first mathematical function relating T s and depth z to the set of S-wave time depth pairs; (e) fitting a second mathematical function relating T p and depth z to the set of P-wave time depth pairs; (f) combining the first and second functions so as to yield an expression relating respective S and P-wave two-way vertical travel time values T s and T p .
Claim 2
Independent Claim
190 words
A method of processing seismic data enabling the correlation of P and S-wave wiggle traces comprising the steps of: (a) transmitting a P-wave and an S-wave into the subsurface of the earth; (b) measuring the two-way vertical travel times of the S-wave to different depths in the subsurface, thereby yielding a set of S-wave time-depth pairs wherein each time-depth pair includes a depth value z and a corresponding S-wave two-way vertical travel time value T s ; (c) measuring the two-way vertical travel times of the P-wave to different depths in the subsurface, thereby yielding a set of P-wave time-depth pairs, wherein each time-depth pair includes a depth value z and a corresponding P-wave two way vertical travel time value Tp; (d) fitting a first mathematical function relating T s and depth z to the set of S-wave time depth pairs; (e) fitting a second mathematical function relating T p and depth z to the set of P-wave time depth pairs; (f) combining the first and second functions so as to yield an expression relating respective S and P-wave two-way vertical travel time values T s and T p .
Claim 3
Independent Claim
304 words
A method of correlating S and P-wave type seismic wiggle traces comprising the steps of: (a) transmitting a P-wave and an S-wave into the subsurface of the earth; (b) measuring the two-way vertical travel times of the S-wave to different depths in the subsurface, thereby yielding a set of S-wave time-depth pairs wherein each time-depth pair includes a depth value z and a corresponding S-wave two-way vertical travel time value T s ; (c) measuring the two-way vertical travel times of the P-waves to different depths in the subsurface, thereby yielding a set of P-wave time-depth pairs, wherein each time-depth pair includes a depth value z and a corresponding P-wave two-way vertical travel time value T p ; (d) fitting a first mathematical function relating T s and depth z to the set of S-wave time depth pairs; (e) fitting a second mathematical function relating T p and depth z to the set of P-wave time depth pairs; (f) combining the first and second mathematical functions so as to yield an expression relating respective S and P-wave two-way vertical travel time values T s and T p ; (g) selecting a plurality of data points in one type wave trace which is to be correlated with the other type wave trace, each type of wave trace being selected from the P and S-wave types, each data point being assigned to a one-type wave two-way vertical travel time value; (h) computing for each one type wave vertical travel time value a corresponding other type wave vertical travel time value from the expression relating T s and T p ; (i) reassigning each data point on the one type wave trace to a corresponding other type wave two-way vertical travel time value, thereby producing a rescaled one-type wave trace correlated with the other type wave trace.
Claim 4
Independent Claim
304 words
A method of correlating S and P-wave type seismic wiggle traces comprising the steps of: (a) transmitting a P-wave and an S-wave into the subsurface of the earth; (b) measuring the two-way vertical travel times of the S-wave to different depths in the subsurface, thereby yielding a set of S-wave time-depth pairs wherein each time-depth pair includes a depth value z and a corresponding S-wave two-way vertical travel time value T s ; (c) measuring the two-way vertical travel times of the P-waves to different depths in the subsurface, thereby yielding a set of P-wave time-depth pairs, wherein each time-depth pair includes a depth value z and a corresponding P-wave two-way vertical travel time value T p ; (d) fitting a first mathematical function relating T s and depth z to the set of S-wave time depth pairs; (e) fitting a second mathematical function relating T p and depth z to the set of P-wave time depth pairs; (f) combining the first and second mathematical functions so as to yield an expression relating respective S and P-wave two-way vertical travel time values T s and T p ; (g) selecting a plurality of data points in one type wave trace which is to be correlated with the other type wave trace, each type of wave trace being selected from the P and S-wave types, each data point being assigned to a one-type wave two-way vertical travel time value; (h) computing for each one type wave vertical travel time value a corresponding other type wave vertical travel time value from the expression relating T s and T p ; (i) reassigning each data point on the one type wave trace to a corresponding other type wave two-way vertical travel time value, thereby producing a rescaled one-type wave trace correlated with the other type wave trace.
Claim 5
Dependent Claim
24 words
A method as recited in claim 2, further comprising the step of plotting the rescaled one-type wave trace and the other type wave trace.
Claim 6
Independent Claim
44 words
A method as recited in claims 1 or 2 wherein, in step (a), the P and S-waves are transmitted from a source on the earth's surface offset in horizontal distance from a set of depth points, each depth point being at a different depth.
Claim 7
Dependent Claim
71 words
A method as recited in claim 4, wherein each of said measuring steps (b) and (c) includes the steps of: measuring the direct travel time of the wave along a direct travel path from the source to each depth point; converting each direct travel time to one-way vertical travel time; and converting each one-way vertical travel time to two-way vertical travel time by multiplying each one-way vertical travel time by two.
Claim 8
Dependent Claim
34 words
A method as recited in claim 5, wherein the P and S-wave wiggle traces to be correlated result from the transmission of the P and S-waves into the subsurface as recited in step (a).
Claim 9
Dependent Claim
36 words
A method as recited in claim 6, wherein said direct travel time measuring step includes the step of: positioning a geophone at each depth point so as to detect the wave directly arriving from the source.
Claim 10
Dependent Claim
51 words
A method as recited in claim 7, wherein step (f) comprises the steps of: solving one function for z to yield an expression for z in terms of travel time; and substituting the expression for z into the other function to yield the expression relating T s and T p .
Claim 11
Dependent Claim
13 words
A method as recited in claim 8, wherein the functions are cubic functions.
Claim 12
Dependent Claim
14 words
A method as recited in claim 8, wherein the functions are cubic spline functions.
Claim 13
Dependent Claim
13 words
A method as recited in claim 8, wherein the functions are quadratic functions.
Claim 14
Independent Claim
45 words
A method as recited in claims 1 or 2 wherein, in step (a) the P and S-wave are transmitted by a surface source, the P and S-waves being reflected by subsurface reflectors, wherein a reflection event correspond to each type of wave for each reflector.
Claim 15
Dependent Claim
68 words
A method as recited in claim 12, wherein steps (b) and (c) comprise the steps of: surface detecting the reflected P and S-waves; determining two-way vertical travel times for each reflection event of the reflected P and S-waves wherein the two-way vertical travel times so determined for the P and S-waves are T s and T p values respectively; and calculating the depth z of each subsurface reflector.
Claim 16
Dependent Claim
50 words
A method as recited in claim 13, wherein step (f) comprises steps of: solving one function for z to yield an expression for z in terms of travel time; and substituting the expression for z into the other function to yield the expression relating T s and T p .
Claim 17
Dependent Claim
13 words
A method as recited in claim 14 wherein the functions are cubic functions.
Claim 18
Dependent Claim
14 words
A method as recited in claim 14 wherein the functions are cubic spline functions.
Claim 19
Dependent Claim
13 words
A method as recited in claim 14 wherein the functions are quadratic functions.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
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