Commissioner's Decision
Computer Related, Section 2, Obviousness
The system of obtaining signals having different angles of
reflectivity by apparatus which provides impulses from
equidistant multiple point offsets is acceptable subject
matter under Section 2. The claims did not define the
apparatus over the cited art. Rejection under Section 2
withdrawn. Claims refused. Rejection modified.
This decision deals with Applicant's request for review by the Commissioner of
Patents of the Final Action on application 294,139 (Class 349-20) assigned to
Chevron Research Company entitled METHOD FOR INTERPRETATION OF SEISMIC RECORDS
TO YIELD INDICATIONS OF GASEOUS HYDROCARBONS. The inventor is W.J. Ostrander.
The Examiner in charge issued a Final Action on December 24, 1981, refusing to
allow the application. A Hearing was held on October 22, 1986, at which
Applicant vas represented by his Patent Agent Mr. D. Cameron.
This application relates to a seismic method of obtaining for a subsurface
point a series of acoustic signals having different angles of reflectivity, as
shows in the drawing below. A common depth point, CDP, is selected and its
surface vertical point Z located. Arranged in line on respective sides of
point Z are the series of equidistant surface shot points, for example, SP1 to
SP5, and the series of geophones G1 to G5 of the same equidistant surface
spacing as the shot points. The shot from SP1 is received by G1, the shot from
SP2 by G2, etc. The successive angling of the shots into the geological makeup
of the same CDP, as in the sketch below, obtains different horizontal
components of the signals received therefrom.
(See formula 1)
The method then displays for each CDP its multiple seismic reflection signals
on a side by side basis as a function of the progressively changing horizontal
values. By observing the horizontal increase in the values for a plurality of
adjacent subsurface points, an improved understanding of the gas content in a
surveyed area is obtained. Part of figure 13a is reproduced below. The
increase from right to left in the peaks of the signals, as shown at the mid
point of the values of the signals for the two shot points shown, is said to
indicate the presence of gas in a strata.
(See formula 1)
In the Final Action, the Examiner refused the claims and the application in
view of the following references:
United States Patents
3,354,985 Nov. 28, 1967 Sparks
3,381,266 Apr. 30, 1968 Harris
Publication
"Seismic Signal Processing" by Wood et al, Proc IEEE, Vol. 63, No. 4, April
1975, pp. 649-661.
The Examiner assessed the references as follows:
Sparks teaches a seismic prospecting method of locating a
suspected fault.
Harris describes a method of stacking Seismic traces having
common offset distances.
The publication provides a review on data signal processing
of seismic survey data.
The Examiner, is making a further rejection of the claims and the application
in view of Section 2 of the Patent Act, said, in part, as follows:
Section 28(3) of the Patent Act prohibits a patent for any
mere scientific principle or abstract theorem. The process
defined in the claims consists of calculations to manipulate
seismic generated data to obtain more meaningful data. If
the calculations were not by a computer, they would clearly
consist of mental operations in solving mathematical
formulae which can be characterized as a mere scientific
principle or abstract theorem.
To determine if the defined process is statutory subject
matter within the meaning of Section 2 of the patent Act, we
turn to the Patent Office guideline and the jurisprudence.
The criteria on patentability of programmable inventions,
commonly called computer programs, were published in the
CPOR on August 1, 1978 and were later adopted by the
Commissioner of Patents.
The same criteria were also set forth in Commissioner's
Decision no. 441 which was considered in Schlumberger v.
Commissioner of Patents (F.C.A. June 15, 1981). That case
was directed to a method of processing well logging data to
produce output parameters representative of geological
formation characteristics. The court found that the claims
define the discovery that by making certain calculations
according to certain formulae, useful information could be
extracted from certain measurements. The court stated that
if calculations are not mental operations but purely
mechanical ones that constitute the various steps in the
process then the use of computers to perform the
calculations would have the effect of transforming into
patentable subject matter what would, otherwise, clearly not
be patentable. A computer used to implement a discovery
does therefore, not change the nature of a discovery. The
process was held not to be an invention within the meaning
of Section 2.
The Applicant argues that his claims and application are allowable over the
cited art, and in view of Section 2, saying in part, as follows:
...
Wood et al ... state as to whether or not obliqueness in the
incident wave is of importance, as follows:
"Appropriate equations for oblique incidence are much
more complicated [28], because mode conversion must be
taken into account. Nevertheless, normal incidence
coefficients are very useful and quite accurate for
stacked traces in areas having simple geological
structures." (Emphasis added)
Hence, in effect, the Wood et al reference teaches away from
Appellant's invention in that it suggests that the appropri-
ate equations can be solved using normal reflection coeffi-
cients since such coefficients are "very useful and quite
accurate" in predicting the presence of gaseous hydro-
carbons, and equations for oblique incidence "are much more
complicated because mode conversion must be taken into
account."
Furthermore, the authors state that amplitude anomalies of
seismic records can also be misinterpreted so that care must
be taken in their use in predicting the presence of gas in
specific stratigraphic areas.
...
Harris relates to a method of gathering and displaying seis-
mic data to enhance normal moveout estimation and to identi-
fy primary and multiple reflections. The key: stacking
traces with a common offset, i.e., combining traces that lie
along a common horizontal line in the diagrams of FIGS. 2
and 3. But note in Harris there is no teaching of
de-stacking of common GATHERS of data followed by the dis-
play of the de-stacked data as a function of "common
centerpoint" location to indicate the presence of events
associated with gas-bearing strata, as described in claims
1-12 of record.
. . .
Sparks relates to a seismic prospecting method for locating
a suspected fault based upon "critical angle" exploration
techniques. Key to operations: each stratification of the
subsurface has a characteristic critical angle of reflection
and critical distance determinable by well-known methods.
But where such data abruptly change, the reflecting sub-
surface can be interpreted as being a fault zone. Hence, by
plotting "critical" amplitude response as a function of
horizontal distance as the array moves toward and through
the fault zone, the latter can be made to stand-out on the
resulting record. . . .
But note in Sparks there is no teaching of display of common
gathers of data of conventional CDP collection techniques
(which are below critical angles) followed by the display of
such data as a function of common centerpoint location to
indicate the presence of gas-bearing strata. . . .
(There's a reason why Sparks only displays maximum response
values in his display of FIG. 1B. Beyond the critical
angle, the phase of the received wave changes in non-
hyperbolic fashion. Consequently, even in areas associated
with gas sands, Sparks' method would not yield the results
specified in the instant claims, that is to say, the
responses associated with the common centerpoints of Sparks
would not progressively change as a function of horizontal
offset even if Sparks had displayed all signals. This is
because the "critical angle" responses of Sparks would
effectively interact with any responses due to gas sands in
an unknown non-hyperbolic manner that would essentially
destroy amplitude response.)
...
Appellant's traces are merely collected in the field using
conventional CDP collection methods. From that time-frame
through to the end of the last step of Appellant's method,
the collected traces are not mathematically treated or en-
hanced in any manner. What is done is the traces are
rearranged (re-formatted) and then displayed in a new
arrangement as set forth in Appellant's Claims 1-12, of
record.
(That is to say, if the amplitude of the event of interest
progressively changes with offset IN THE DISPLAYED TRACES,
then more likely than not the subsurface reflectors of the
seismic energy were gas sands.)
The issue before the Board is whether or not the claims and the application are
acceptable in view of Section 2 of the Patent Act, and whether or not they are
obvious in view of the cited art. Claim 1 reads:
A method for increasing resolution of high-intensity ampli-
tude events in seismic records in order to associate such
events with gas-bearing strata is the earth, comprising the
steps of:
(a) generating seismic data, including a record of sig-
nals from acoustic discontinuities associated with said
strata of interest by positioning and employing an array of
sources and detectors such that centerpoints between
selected pairs of sources and detectors form a series of
centerpoints along a line of survey, said recorded signals
being the output of said detectors;
(b) by means of automated processing means, statically
and dynamically correcting said recorded signals to form
corrected traces whereby each of said corrected traces is
associated with a centerpoint horizontally midway between a
source-detector pair from which said each corrected trace
was originally derived;
(c) by means of automated processing means, indexing said
corrected traces in two dimensions whereby each of said
corrected traces is identified in its relationship to
neighboring traces on the basis of progressive changes in
horizontal offset value versus progressive changes in common
centerpoint location.
(d) displaying a series of said traces of step (c) on a
side-by-aide basis as a function of progressively changing
horizontal offset values, said displayed traces all being
associated with at least the same general common group of
centerpoints;
(e) identifying progressive change in a high-density
amplitude event from trace to trace of said displayed traces
as a function of progressive change in horizontal offset
value whereby more likely than not said event relates to
reflections from acoustic impedances associated with strata
containing gaseous hydrocarbons.
At the Hearing, Mr. Cameron explained that the common depth point analysis, in
use prior to Applicant's invention, gathered signals together in a summing
step, and presented them on a graph where they appeared as spots. He says the
more pronounced spots, known as bright spots indicated formations of interest
in the subsurface, and that there might be gas in such formations. He says
numerous dry holes drilled in such areas point to shortcomings in the previous
method. He describes Mr. Ostrander's method is, not to add the signals to-
gether, but instead to arrange them in a display so that the horizontal ampli-
tudes of the signals obtained are visible. Further, he emphasizes Mr.
Ostrander's method enables a more accurate prediction of gas in the substrata
if the horizontal amplitudes increase progressively in accordance with the
changing angles of reflectivity provided by the shot points spaced away from
the center point overlying the common depth point.
Mr. Cameron provided a comparison between the known manner of collecting data
with that developed by Mr. Ostrander. For example, by looking straight into a
non-glare glass surface, he noted there would not be much reflectivity. How-
ever, on moving sideways from the surface, and so changing the angle of
reflectivity, the surface acts more like a mirror and provides a clearer
reflection. He likened this to an optical phenomenon. He referred to
Mr. Ostrander's realization that, by providing multiple shot points and
receptors on each side of a strata point to obtain different angles of inci-
dence, a contrast could be obtained in the signals, and thereby an indication
whether the strata is gas containing. Part of Mr. Ostrander's technique makes
use of the knowledge of how signals react in gaseous material and in hard
material, for example a signal passing through a gaseous deposit will produce a
different value from a signal passing through hard material.
Mr. Cameron, in referring to the decision in Schlumberger Canada Ltd. v. The
Commissioner of Patents (1981) 56 C.P.R. 204, stressed that the Applicant is
not attempting to monopolize an arithmetic procedure to do calculations for
signal processing. He says Applicant is attempting to protect a method of de-
tecting subsurface gas deposits. We find direction in assessing Applicant's
invention in the following passages from Schlumberger:
In order to determine whether the application discloses a
patentable invention, it is first necessary to determine
what, according to the application, has been discovered,
and
I am of opinion that the fact that a computer is or should
be used to implement discovery does not change the nature of
that discovery. What the appellant claims as an invention
here is merely the discovery that by making certain calcula-
tions according to certain formulae, useful information
could be extracted from certain measurements. This is not,
in my view, an invention within the meaning of s. 2.
We are aware from the disclosure and from Mr. Cameron's explanation that the
signals from the shot points are subjected to certain calculations, such as are
the signals produced by the common depth point analysis referred to by him. We
learn from his explanation and from the description of how the apparatus is set
up to emit several offset signals for each point of interest in the strata,
that Applicant's features are the multiple point offset for each CDP and the
different angles of reflectivity. In our view they produce the results not
previously attainable by the methods of the cited art references.
We are satisfied therefore that the claims and the application are directed to
patentable subject matter under Section 2 of the Act.
In reviewing the claims, we do not find any definition of the step of providing
the multiple array of equidistant sources and detectors to obtain signals
having progressive angles of reflectivity for each CDP. Part (a) of claim 1
does not refer to the progression of angles for the signals needed to obtain
the horizontal values that Applicant contends provide the significant differ-
ence from the cited art. Part (a) merely calls for an array of sources and
detectors such that centerpoints between selected pairs of sources and de-
tectors form a series of centerpoints. As noted in the arguments to the Final
Action and at the Hearing, the manner of progressively varying the angles of
reflectivity obtained from the equidistant offset shot points is part of the
method needed to produce the signals that provide the horizontal amplitudes.
In our view, part (a) of claim 1 does no more than recite what has been argued
as being known in the cited art to obtain the values for the bright spots
which, as Applicant points out, have not always indicated gas bearing strata.
Part (c) of claim 1 appears to rely on automated processing means to index and
correct signals to obtain the desired horizontal offset value. We do not see
that this part relates the necessary equidistant placement of multiple shot
points and receptors in terms that define over the arrays provided by the cited
references. We find claim 1 is indefinite and does not define over the cited
art .
None of the other claims, in our view, recite an arrangement of sources and
detectors that define the arrangement that Applicant argues is different from
the cited art. Therefore, all of the claims fail to define the step of
arranging Applicant's structure to obtain the various angles of incidence that
provide the reflection profiling containing indications of progressive
amplitude change.
We recommend that the rejection of the application for not containing
patentable subject matter be withdrawn. Concerning the refusal of the claims
for not defining the invention in view of the cited art, we recommend that the
rejection of the claims be maintained.
M.G. Brown S.D. Kot
Acting Chairman Member
Patent Appeal Board
I concur with the findings and the recommendations of the Patent Appeal Board.
Therefore, I affirm the refusal of claims 1 to 12 for not defining an invention
over the cited art, and I withdraw the rejection of the claims and the
application for being directed to non-statutory subject matter. Accordingly, I
refuse to grant a patent containing claims 1 to 12. The Applicant has sin
months within which to appeal my decision under the provisions of Section 44 of
the Patent Act.
J.H.A. Gari‚py
Commissioner of Patents
Dated at Hull, Quebec
this 10thday of June 1987
Sim & McBurney
Suite 701
330 University Avenue
Toronto, Ontario
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