Note: Descriptions are shown in the official language in which they were submitted.
01 --1--
GROUND POSI'rION CONTROL,r.l'E~ ,~ND ML!T~IOD FOR
AUTOMATICALLY INDIC~TING ANI~ RE(,'ORDIMG
PARAMETERS Tl-IAT SPATIAL,LY l:)EFINE LOCA'rIOl~S
05 OF SEISMIC EXPLORATION SPR~,Ar~ AND SO~RCE ~RRAYS
: SCOPE OF 1'1-11~ V~N'I':ION
This invention relates to seislrlic explorcltion
and more ~artlcularly to Inethods and apparatl1.s for
insuring inteyrity of field shootiny and reco~ding opera~
tions durillg cxp]oratiorl ~or hy(lrocarborls and the like.
In one aspect, the present invention provides
for dynamic control of the field shooting and recordirlg
operations so that the latter actually correspond to the
advaneed specifications Eor those operations; as a result,
recording operations can be coordinated with the speci~ied
shooting (or vibrating) operations. In aecordanee with
another aspect, the present invention provides for the
generation and recording of data including array anc3
source geometry information on a reeording media as header
data in addition to the reeording of seismie data repre-
senting aeoustie signals reeeived as -the eonsequenee of
shooting (or vibrating) operations.
BACKGROI]ND OF T~IE_INVFNTION
25In seismie exploration, proposed prescriptions
for shootin(3 (or vibrating) and reeording operations rnust
be followed -- preeisely -- in the field, partieularly in
fielcl teehniques involving so-ealled Common Depth Point
Reeording (or CDPR) operations ln whieh ehangincJ sets of
sensors were used in assoeiation with successive shots to
provide multiple staeked recordings. (In all of the
following teachings, the words "shots" and "shooting" will
be used for the part of the operation in whieh the sound
waves are generated and sent down into the sub-surface.
It will be appreciated, however, by those skilled in the
art, that the sarne teachings apply where the sound waves
are generated by large vibrators at the surface rather
than by explosive shots.)
~0
01 -2-
ln the CI~PR proccss, sensors and erleryy sources
are positioned at a first seLies of spatiall~ (geollletri-
05 ally) relate~d locations, to produce a first record. ';ub~sequent records are tllerl made with the s(?nsors an-3 thf~
energy source occupying new locations. Ilowever, the sen
sors ancl eneryy source norTnalLy maintairl the salne reLative
spatial relationship to each other during the Eiek~ ope~a-
tions.
Advancemellt oL the sensor locatiorls (in cnl?Roperations) employ a technique comrllonly knowll as "roLl-
alollg". Relative advancelnellt o the sensor array is
common:Ly done in a very rapid manner usinc3 a switching
device callec] a rollaloncJ switch (such as shown, e.g., in
my U.S. Patent 3,61~,000, November 2, 1971 or "Rollalong
Switch"), in which a large number of sensors can be COTl-
trollably provided at any programrned interval along the
recording line. Through the use of multiple pair cables
extending along the line, these sensors are connected into
the input receptables of the rollalong switch. The design
of the switch permits a certain number of the sensors,
called the "active" array, to be interconnected to the
input of the geophysical seismic recorder and keeps track
of t~le position of one end of the active array relative to
the number of recording channels available (say, any posi-
tion within l-in-60 channels). Not only can the switch
select any contiyuous group of sensors, Erom the total
number positioned along the line, as the "active" array or
spread, but it can also add gaps in the active spread
using one or more "inactive" groups as the gapping
rnembers, a technique usually used when a large energy
source is positioned at the center of the active array.
(A l'gapped" array for a 24-sensor record, for example,
35 consists of sensors 1 through 12 and 15 through 26 with
sensors 13 and 14 left disconnected by the rollalong
switch.)
Computer processing oE the CDPR field data (now
commonly done by large centralized computer facilities)
requires not only accurate time-versus-amplitude seismic
01 3_
rc?flection data but also requires "housekeepirl<J" data
describing associated source and sensor geornetry as the
05 former was collected. These latter data consist o~, inter
a_ia, positional locations for every sensor in each
"active" array during the recording sequerlce, the location
of the eneryy source, and the location and sizc of the gap
(if any). To provide the above, the usual Eie:Ld procedure
1~ is to determine the groun(3 locations hy survcy prior to
the recordiny operations. 'I'he location al-l(l direction or:
the line is reEerellced to know geographic locations or
yeodetic survey points. The Location of each sensor (or
sensor group) and energy source is surveyed in and rnarked
with a survey stake having an identification number repre-
senting a c3round location. These locations are written
down in the survey log for that particular seismic line.
The surveyor's log thus contains part of tht? gC?olnetriCa]
data that must be added to the seismic data after the
2U latter has been recorded and is ready for processing.
Another requirement of the geometrical data is
developed during the recording process. It relates to
data entered into the "observer's log". (The operator of
the seismic recordiny system is commonly called the
"observer".) The observer's log contains, for each record
sequence, the spatial extent of the active sensors usually
identified by yround locations of the sensors at each end
of the active array. In the event that the active array
contains a gap, the location of the gap will be specified
relative to adjacent active sensor locations. The
observer's loy also contains the location of the energy
source for each record. In some cases, when a presurveyed
line is recorded, ~he energy source cannot be located at
the location designated for it duriny the survey. In
these situations, the shot location from the observer's
log must be used in processing instead of the original
survey data. The observer's log also contains information
that infers or describes spatial irregularities in the
active array imposed by Eield conditions wllen the line is
recorded.
. D ~ ,r
~ s previously inciicated, thr rollalony switch
tracks the position of active array (~or identifying tlle
05 location o~ the "active" sensor array ineluding yap).
While some rollalong swlteh units provide for transferring
such array data directly to t~le Eield reeorder (recogniz-
able as header data on the digital seismic tape), these
data are not in terms of true~ c~roun(l location/ but in an
arbitrary nurnberilly sec~lletlce, relative to a partieular
recording vehicle location. '[`he true grollnd location o~
the recording vehicle must there~ore be ente~ed into the
observer's loy in order to convert rollalong switch posi-
tions to true ~round locations.
Tl-~e foregoing description of geophysical seismie
data reeordiny operations indieates eonelusively that the
recording o~ seismic refleetion data must be supported by
aecurate and suffieient eorrelative data so as to aceu-
rately define spatial souree ancl sensor geometry relative
to a permanent geographieal loeation. It also indieates
that separate types of eross-eheeking materials, for
doeumentation, are needed as the data is colleeted,
ineluding the steps of generating, Eormatting and
displaying spread and sound geometries for both present5 and next-in-time shooting and recording sequences.
SUMMARY OF TE~E INV~NTION
One particularly useful embodiment of the inven-
tion eomprises a ground position controller for generat-
ing, formatting and recording information for insuring the
integrity of field shooting and reeordiny operations. The
controller includes sets of multi-digit displays dynamie-
ally eontrolled by a mieroeomputer system inter-connected
to the exploration system. Before the source is activated
and spatial ~eometrieal parameters reeorded, the operator
examines -- colleetively -- all displayed data and cross-
checks those results with prescribed instructions; then,
after he signals that the data do represent the desired
field operations by e.g., activating a transmission
linkaye swit(ll, the displayed data (both encoded and eal-
~0 culated) can be transferred as header data to a field
--5--
recording unit in series with the control~Ler~ Prior to
transfer, the controller also formats the data in a form
required for proper annotation of the seismic record. As a
result, the final seismic record contains data representing
original array/source geometrical data that can be
unambiguously associated with the recorded seismic information
received from the subsurface as a result of the particular
operational sequences. At the end of the recording cycle, the
controller generates a series of new data: (i) new shooting and
spread geometries, and (ii) positional skips tgaps) of the
array. Then the sequence can be repeated. Thus, the present
invention translates original operational instructions into a
presentation accurately suitable for annotation of the seismic
data, such data being in a form that the field operator can
quickly cross-check via displays before operations are
concluded. Also, the present invention aids the operator in
cross-checking and cross-listing data so that any deviation
from the prescribed field procedure can be detected and
corrected. Finally, coded descriptions of actual operations
2a can be unambiguously associated with recorded seismic data
received from the subsurface as a result of particularly-
described field operations.
Various aspects of this invention are as follows:
Method of calculation, storing and recording positional
data associated with a digital exploration system during
generation and collection of seismic data by a source-detector
array positioned at known locations along a line of survey,
said positional data being generated as bits of digital data
stored in a microcomputer system including a microprocessor
unit (MPU), memory units, and a series of display/storage and
switching devices interconnected to each other and to a digital
field system (DFS) via a system bus, whereby errors in
" Y~
-5a~
exploration activities are xeduced, and annotation of
exploration activities is automatically aclded, comprising
(a) establishing in digital format via said microcomputer
system, array geometry and exploration parameters that allow
annotation in sequence of exploration activities along said
line,
(b) automatically displaying at said display/storage and
switching devices of said system, at least a portion of data of
(a) an alpha-numeric form for operator e~amination and
correction, if requ.ired, and
(c) automatically recording said portion of data of (a) as
header data so as to provide full annotation of exploration
activities whereby errors in such exploration activities can be
discovered and accounted for.
Method of calculating, storing and recording positional
data associated with a digital exploration system during
generation and collection of seismic data by a source-detector
array positioned at ~nown locations along a line of survey at
the earth's surface, said positional data being generated as
bits of digital data in a microcomputer system including a
microprocessor unit (MPU), memory units and a series of
display/storage and switching devices interconnected to each
other and to a digital field system (DFS) via a system bus,
whereby errors in exploration activity -- both pre-activation
and past-release of energy f.rom said source -- are
substantially reduced, comprising
(a) encoding and automatically storing additional digital
data related to array geometry and exploration parameters that
allow repetition in sequence of activities along said line,
(b) automatically displaying at least a portion of said
encoded data in alpha-numeric form for operator examination and
for correction, if required,
-Sb-
(c) automatically generating via said microprocessor
system further additional data related to array parameters
based in part on data encoded at (a), and previously stored
data related to exploration parameters,
Id) displaying at said display/storage and switching
devices of said microcomputer system at least a portion of said
new array parameters of (c) for operator examination and
correction, if required, and
(e) automatically recording portions o~ said displayed
data of steps (b) and/or (d) as header data so as to provide
full annotation of exploration activities whereby errors in
such activities can be pinpointed and taken into account.
A ground position controller for manipulating calculating,
storing, displaying and causing recordation of positional data,
associated with a digital exploration system during generation
and collection of seismic data by a source-detector array
positioned at known locations along a line of survey at the
earth's surface, whereby errors in exploration activity -- both
pre-activation and past-release of energy from said source ~-
are substantially reduced, said positional data being generatedas bits of digital data using a microcomputer system comprising
a microprocessor unit (MPU), memory units, and a series of
display/storage and switching devices interconnected to each
other and to a digital field system (DFS) via a system bus,
said display/storage and switching devices including separate
encoding means for automatically encoding digital data related
to array geometry and exploration parameters that allow
repetition in sequence of activities along said line of survey,
separate display means for automatically displaying at least a
portion o~ said encoded data in alpha-numeric form for operator
examination and for correction, if required, before activation
of said source, and separate switch sequencing means, connected
to said microcomputer system and to said DFS for initiating, on
-5c~
command, an operational signal leading (i) to the recording of
portions of said encoded and disp].ayed data onto magnetic tape
at a recorder unit of said DFS, and subsequently (ii) to
activation of a seismic source of said array, said displayed
data at said separate display means being automatically
generated via said microcomputer system using data related to
array parameters based in part on encoded data, previously
stored data related to exploration parameters, and newly
generated array parameters whereby errors in exploration
activities can be substantially reduced; said recorded data
being associated with source and array positions vis-a-vis said
known geographical positions along said line of survey.
Method of calculating, storing and displaying positional
data, associated with a digital exploration system during
generation and collection of seismic data by a source-detector
array positioned at known locations along a line of survey at
the earth's surface, said positional data being generated as
bits of digital data in a microcomputer system including a
microprocessor unit (~PU), memory units and a series of
display/storage devices interconnected to each other and to a
digital field system (DFS) via a system bus, whereby errors in
exploration activity -- both pre-activation and past-release of
energy from said source -- are substantially reduced,
comprising:
(a) encoding and automatically storing additional digital
data related to array geometry and exploration parameters that
allow repetition in sequence of activities along said line,
(b) automatically displaying at least a portion of said
encoded data in alpha-numeric form for operator examination and
for correction, if required,
(c) automatically.generating via said microcomputer system
further additional data related to array parameters based in
.F ~ J
-5d-
part on data encoded at (a), and previously stored data related
to exploration parameters, and
(d) displaying at said display/storage devices of said
microcomputer system at least a portion of said new array
parameters of (c) for operator examination and correction, if
required, whereby errors in exploration activities can be
substantially reduced, pri.or to activation of said source of
said array.
A ground position controller for manipulating,
calculating, storing and displaying positional data, associated
with a diyital exploration system during generation and
collection of seismic data by a source-detector array
positioned at known locations along a line of survey at the
earth's surface, whereby errors in exploration activity -- both
pre-activation and past-release of energy from said source --
are substantially reduced, said positional data being generated
as bits of digital data comprising a microcomputer system
including a microprocessor unit ~MPU), memory units and a
series of display/storage devices interconnected to each other
and to a digital field system (DFS) via a system bus, said
display and storage devices including separate encoding means
for automatically encoding digital data related to array
geometry and exploration parameters that allow repetition in
sequence of activities along said line o~ survey, said separate
display means for automatically displaying at least a portion
of said encoded data in alpha-numeric form for operator
examination and for correction, if required, said displayed
data at said separate means being automatically generated via
said microcomputer system using data related to array
parameters based in part on encoded data, previously stored
data related to exploration parameters, and newly generated
array parameters whereby errors in exploration activities can
be substantially reduced.
-5e-
These and other advantages and functions of the present
invention will become evident to those skilled in the art
having a reading of the detailed description of speclfic
embodiments thereof, following a brief description of the
appended drawings.
DESCRIPTION OF THE DRA~IINGS
FIGS. 1 and 2 illustrate an exploration system
incorporating the present invention in which an energy source
and an array of sensors (connected to a recording truck) are
illustrated.
FIGS. 3 and 6 are block diagrams of the ground positioned
controller of the present invention used within the exploration
system of FIGS. 1 and 2.
FIG. 4 is an isometric view of a display panel of the
controller FIGS. 3 and 6.
p~
01 -6-
~;`IG. 5 is a block diac~ram oL a rnicroprocessor
urlit of the controller o(- F:tGS . 3 and 6.
05 FIG. 7 is an imaginary r-ndition of heac'~er data
encoded onto maynetic tape usincJ the contro]ler of the
present invention in association ~ith the recording unit
of the exploration system of FIGS. 1 and 2.
FIG. 8 is a block diagram of ~)ortions of the
circuitry comprising the controller of r'lGS. 3 and 6, and
recorder unit used in the exploration system of E~'IGS. 1
and 2.
~I(.S. 9A-9C are Elow diagrams which illustrate
thf- method of the present invention.
L5 FIG. 10 is a partially schematic diagram of the
recorder unit of FIG. 8 illustratiny a secluence of opera-
tions, associated therewith.
DE~CRIP'rION OF
PREFERRE~D EMBODIMENT,S OF THE INVE 'ION
FIG. 1 illustrates operation of seismic explora-
tion system 9 of the present invention.
As shown, system 9 ineludes digital field systern
( DFS) 10, housed within recording truck 11 and electric-
ally interconnected via a multiwire geophyslcal cable 12
25 to an array of sensors 13 positioned at the earth's sur-
face 14.
Ground locations 15 are represented as sur-
rounding both the array of sensors 13 and seismic energy
source 16, all positioned along the surface 14. As pre-
viously mentioned in the C~RR collection process, theground locations 15 would, more likely than not, have been
previously surveyed prior to implementation of the seismic
surveying operation along the line of survey 17 in the
direction of arrow 18. Hence, each of the locations 15
can be designated by a particular position number (or
P number) along the line 17. The P numbers set forth in
FIG. 1 include the numbers 300, 301... 329. Also, the
number of sensors 13 forming each array (as the data is
~0
()1 -7-
collected) is identified by the seqllence nurllbers N, N-~l...
N+M designating the length of the active array as the
05 sensors 13 are advanced in the direction of arrow 1~.
Annotating the positions of the sensor arr.lys is
aided by tlle fact ~hat each sensor is associated with a
particular clata channel 1, 2...K of the DFS lO as the data
is collected. F`or usual operations K can be 24, ~3, 60,
96, 120, etc., as recluired, althoucJh, of course, t:he pre-
sellt invention is not limited to a partic~l]ar cllclnrlel
capacity number, but can be varied to accornmodate any
field arrangemerlt. ~ach sensor position and each source
location can be indicated using the ground pc~sitiorl con-
~S troLler 20 oi the~ present invention in conjunction withrecording ~nit 21 of the DFS 10.
~ tG. 2 illustrates ground position controller 20
in Inore detail.
Briefly, the yround position recorder 20
operates in the field to insure integrity bet~Jeen pre-
scribed and actual field shooting and recording operations
by a series of steps, narnely, storing, manipulating and
displaying data related
(i) to field positions of the source and sensor
array by position number,
(ii) to array and source geometrical locations
(both present and next-in-time) based on field ~eometrical
algorithms and
(iii) to recording array and source parameters
so that realistic annotation of the subse~uently collected
seismic data, can be made. For -these purposes, the
operator utilizes encoded data provided initially by him
using encoders 26, manipulated results generated by the
controller 20 based on part in stored relationships within
the rnicrocomputer 25, and finally indicating geometrical
data set forth at displays 27 and as header information at
recording unit 21.
Since the present invention deals conveniently
~ith the CDPR process, the array of sensors 13 and source
of energy 16 are continually "rolled for~ard" in the
3~ 3,
01 _g_
direction of arrow 13 usi.ng rolla:long switch 22. That is
to say, after the seismic data has been recorded at the
05 digital tape recording unit 21 (after amp:Lificatioll by
amplifier 24), the array of sensors 13 (and source 16)
located at a first series of positions P as shown, are
"rolled for~"ard" in the direction o:E arrow l~. Note that
the changing of the active array pattern of E'LC. 1 in the
10 aforelnentioned manner is identified by the array sequence
desigrlated 1`~1~ N-~l... N+M~ as previously mentiorled. But,
the array and source geometry is always ]cnown at the
recording truck 11 provi.ded the positional locations 300,
301, 302...P of FIG. 1 for the particular active array N,
15 N-rl . . . N+M are correctly identified and recorcled during
each recor-ling cycle, via operation of the ground position
controller 20 of the present invention; oi~ particular
im~ortance is the manipulation of data as.soc;ated with the
fiek] geometry of the sensors 13 and source 16 via geo-
:~() metrical and perEormance algorithms stored within mi.cro-
computer 25 of the controller 20.
As previously mentioned, microcolnputer 25 is
used to predict correct array positions as the rollalong
switch 23 switches between "active" and "inactive" arrays
25 of sensors. The microcomputer 25 can also interact with
the rollalong switch 22, provided the latter is capable of
accepting the multi-bit codes conventionally generated by
the microcomputer 25. (In this regard, an approved roll-
along switch is manufactured under the tradename "Rola-
30 long Switch", by Input-Output, Inc., ~ouston, Texas, and
consists of a series of contac-ts attached to a central
shaft of a stepping motor controlled via a digital input
code from the microcomputer 25.)
Rollalong switch 22 usually includes a display
35 (not shown) associated with one or two of the locational
positions of the active array of sensors 13. Such dis-
play, of course, changes as the active array changes
sequential pattern in the manner of N, N+2... N-~M~ as
shown in FIG. 1. The rollalong switch 22 also includes a
40 digital generator (not shown) for generating a second
0l ~ 9~
multi-bit code indicative o~ the position P oL a mernber o~
the sensor array as '-neader inclicia at the recorder 21.
05 ~lowever, as previously mentiol~ed, the latter di~Jital code
represents only an arbitrary nulllber arld is not a true
yeodytic location.
FIG. 3 illustrates microcorllputer 25 of con~
troller 2n in stlll more detail.
As shown, the microcornputer 25 includes a systeln
bus 28 used to connect encoder-s 26 and d i:;play-; 27 via I/O
interfacillc3 array 3~ to microE)rocessor unit 30 (MPU) oE
the microcornputer 25. Also connected via the bus 2~3 and
ports 29 are interrupt controller 31, RAM 32, ROM 33 (in
addition to I/O inter~acing array 34) which operates in
conventional fashion to calculate, rnanipulate, store and
display position data associated with the exploration
operation. Note that the I/O array 34 not only links thc~
MPU 30 witn the encoders 26 and displays 27, but it is
also used to provide data to the printer 35 under control
of MPU 30 to generate a permanent record of the displayed
data at dispLays 27, if desired.
Bus 23 essentiallv comprises three separate
buses, a data bus, an address bus and a control bus. The
data bus is conventional: it not only carries information
to and from MPU 30, but it is also used to fetch
instructions that have been stored irl ROM 33, as required,
as well as carries data frorn/to the encoders 26 and dis-
plays 27 of FIG. 2, by way of (or independent of) RAM 32.
Addressing segments oE the data is the annota-
tions function of the address bus. It is capable of
selecting a location in RAM 32 or ROM 33 or a particular
address in the MPU 30 when appropriately signaled, say by
interrupt controller 31. The eontrol bus controls the
sequencing and nature of the operation using common
selector commands, e.g., "Read", "Write", etc.
Additionally, it should be noted, the system
interrupts are usually carriec] via the control bus to
implement the scheduling and servicing of different ports,
40 as required by operations. -rn the present invention,
3~
nl -10-
interrupt controller 31 nalldl.es scvc?rl (7) vectored prior--
ity interrupts for the MPU 30, as explained below,
05 includinc3 an end-of-record interrupt (~O~) generatecl by
the digital field systern 1(), FIG. 1, to indicate the e~nd
of the collection cycle, and to initiate operations in tne
next-in-time cycle.
:[n genera.L, in scrviciny the interrupts, pr-.ser-
vation of program status is required and is easily carrie(lby the i~l?~ 30. Si.nce thc corltrollcY 3:L :is both vectored
an(l priority oriented, it has the respons,ibility o~
providing vectored interrupts to the MPU 30, oi- identi-
fying the nature of the interrupt, (or its branchi.ncJ
address) and of establishiny priority between competing
interrupts.
In particular in servicing the EOR i.nterrupt,
the steps set forth in FIGS. 9B and 9D are execu~:ed to
bring about automatie updatinq of the array and source
geometry to achieve the next-in-time colleetion of data,
based in part on the field algorithms eontained in equa-
tion sets I, II, III or IV set Eorth below.
FIG. 4 illustrates the nature of the data
provided at encoders 26 and displays 27.
The operator ini-tially ealibrates positions of
the exploration array and souree with previously surveyeci
geographical stations. Information has been already
encoded via the eneoders 26 for use by microcomputer 25
before operations begin. E:ncoded data at encoders 26
includes:
(i) truck location (vis-a-vis survey stations of
known geographic location) encoded at encoder sub--
element 40;
(ii) slave truck location (if applicable)
encoded using encoder sub~element 41;
(iii) reference station location (where the end
of the spread is initially positioned) encoded via
encoding sub-element 42;
(iv) initial location of the energy source
encoded using encoder sub-element 43;
0 1
(v) the number of ;hots or sweeL)s erlco~ d at
sub-elernent 44;
05 (vi) the initial yap position, stored at sub-
element 45;
(vii) the gap spaciny enco(led usiny encoder sub-
element 46; and
(viii) gap roll increment encoded USilly sub-
L0 elernent 47.
The operator also has the ;nitial responsibility
of encodiny other data which, for the rnost part, does not
chan~3e cluriilg the survey. ~n this regar(J, the operator
rnay have to only initially encode shot depth and si~e (at
sub-elemellts ~1~ ancl 49), shot direction and o~fset (at
sub-elements 50 ancl 51) as well as data related to the
spread, as to its direction (at sub-element 52) and the
distance between groups (at sub-element 53).
Switch arrays generally indicated at 54 and 55
are also set by the operator. Data provided by these
switch arrays, relate to two or three possible switch
states of tne switches 56-66 which are, for example,
related to the type of survey and run conditions occurring
after the survey is underway.
[In this regard, the functions of the switches
are as follows: Switch 56 specifies line direction;
switch 57 specifies truck rank, i.e. determines if the
reference truck is the master (or slave) in relationship
with an alternate truck; switch 5~ specifies operations in
either a serial or in a parallel mode, the mode being
related to whether one or two arrays of geophones are used
in-line or parallel to the corresponding source line;
pushbutton switches 59 and 60 relate to start up and to
alarm reset functions respectively; switch 59, of course,
initializes operations after all synchroniza-tion has ~een
completed; switch 60 turns off the audio alarm in the
event that a signal of some importance has been generated
causing the alarm to also activate; transmit switch 61
"triggers" the energy source, and is operative only after
the operator is assured the correctness of the array and
01 -:L2-
source positions as displayed at clisp1ays 27; switches f,2
and 63 related to (i) the "tric3yer" link associated with
05 the activation of the source (electrical wire-line or
radio) and (ii) whether or not the roll switch 22 (FIG 2)
is to be in an active or passive state. Three-position
switch 6~ establishes whether or not the operation is to
be in a manua], automatic or test mode; update switch 65
operates only when t~le switch 64 is in the manual mode ancl
is used (in manual mode) to initiate advances o~ the roll
switch so as to c~enerate new groun(l locations for the
array after the recordincJ cycle has been completed; and
switch 66 is a conventional power-on switch.]
Displays 27 rnay be conventiolla1 L.ED segmented
displays except that they are microcomputer Lmplemented.
Primary purl~oses of the displays 27: to provide data to
the operator so that determinations as to whe-ther or not
the system is ~unctioning correctly can be made, and to
allow the operator to act as an independent cross-checker
of the correctness of the displayed ground locations. ~I'he
data at displays 27 relate for -the most part to the type
of run being undertaken and survey conditions.
[In this regard, the nature of the displays 27
is as follows: subdisplays 70 and 71 indicate shot loca-
tion and number of shots per location, respectively; sub--
displays 72-75 relate to geographic locations of the
active array as a function of time; subdisplay 76 speci-
fies the position of the slave reference; status subdis-
3U play 77 specifies (by code) the occurrence of certainactivities during the exploration operation which may be
accompanied by an audio alarm to indicate the immediate
need for operator intervention, the meaning of the status
code at subdisplay 77 being as set forth below, in
Table I.
9~
01 -13-
~BI~ I
Code AC tivity
05 0 Setup for sequence start operation
Geometrical mistie
2 Ready for update or update in proyress (i
in auto rnode)
3 Roll Switch Moving
4 Roll Switch (Stopped in position)
Roll Switch Disabled
6 Slave ReEerenee Code Receivecl
7 I'ransrnisslon Reference Error (slave
reference coc3e not reeeived)
8 Load Ref Output At ShiEt Re~ister
9 Transrnit (one bit of ref code)
A Gap Set Mistie
D Oceurrence of Last Shot
lX Beeper On With Status Displayed as to Code
:2() 0, 1, .. 9, A, D, alone.
53 Step Roll Switch [lp With Beep on and Code "3"
93 Step Roll Switch Down With Beep on and
Code "3".
Explanation of Table I: status code "0" occurs
any time that the controller 20 is powered up to cue the
operator that all input data at the encoders 26 must then
be set. Sequeneing start button 59 terminates the cueing
operation; status eode "D" indieates that the last shot
30 position is at hand and thus, the truek loeation and
connection station vis-a-vis the array must be changed;
status codes "3", "4", "5" and '!53" and "93" indicate
certain roll switeh activities. If there are errors in
the programmed e:~ploration aetivity, warning codes are
35 also generated by the status codes "1"; and "7".]
OPERATIONAL s~Qur_E
Assume the operator has initially ealibrated the
start-up positions of the array and souree with the sur-
veyed locations. As previously inclicated in regard to
40 FIG. 4, this entails encoding of positional data via
0 1 ~
encoders 26 in conjunction with proper settiny of theswitching arrays 54, 55. The result: correspon~-ling shot,
05 spread and associated data appear at the displays 27 due
to the interaction of data relationship established
through operation oE the microcomputer 25 of FIG. 2. In
order to better understand how the present inventiorl uses
all data, perhaps a brief overview of the hardware aspect:s
of the microprocessor 30 is in order and ls presented
below in connection with E'IG. 5.
It should be initially noted that MPU 30 is
preferably an Intel 8085 microprocessor, a product of
Intel Incorp., Cupertino, California. As i.s well known,
it has a microprocessor and controller integrated into a
sing:Le chip. It also includes an array of registers 82
tied to an ALU 83 via an internal data bus 84 controlled
via control unit 85 Program counter 86 and instructional
register 87 have cledicated uses; the other registers, such
as accumulator 88, have more general uses. In the 8085,
expanded control functions result because the low-eight
(8~ address bits have the capability of being mul-tiplexed.
Such operation occurs at the beginning of each instruct-
ional cycle; the low-eight address lines appear via ALE
line 89 for control of different elements of the location,
including encoders 26, displays 27, and printer 35 through
I~O interface array 34 of FIG. 60
As shown in FIG. 6, while the I/O array 34 is
conventional, it must be capable of handling a series of
8-bit independently addressable codes. For this purpose,
it preferably comprises a multiplicity of ~-bit I/O port
chips indepedently addressable via ALE line 89 of FIG. 5
of the MPU 30. Each 8-bit I/O port chip preferably com-
prises an 8-bit latch combined with a 3-state output
buffer in which each can be separately driven. In deter-
mining location of data via address decoder 38, the MPU 30
also must manipulate the data using known geometrical
relationships in which encoded positional data can be
translated as required, depending on several factors.
0 1
Assu~ne the survey has just been started; the
operator has ellcoded all pertinellt data via the encoders
05 26. Also switch arrays 54, 55 have been properly set.
Initially the contro:L and reference location ~osition c]dta
from encoders 26 (ancl the switch arrays) are fetched by
the MPU 30. The MPU 30 next performs the required Inani~Ju-
lation of that data to define spatial array arld source
geometries of interest in the manrler oE l`[GS. 9A and 9C.
Such mani~ulation of data includes executiorl of the ster>s
associated with the ba;ic power-up routine of FIG. 9~ an(l
tile sequence start routine o~ F[G. '~, inc:Luding accessing
thc calculated data to clisplays 27 Eor operator perusal
DATA ARRANGEMEN~S AT DIS _AYS 27
Values of data appearing at displays 27 oE F`IG.
4 are, of col~rse, dependent upon use of certain geometri~
cal equation sets viz. equation .sets [ II III and IV
set forth below, s~ored in the MPU 30 and selectively
utilized by the controller 20 as required.
SEQUENCE START EQU TION_SET I
Assume both the ground location numbers and data
channel numbers increasing along the seismic line in the
direction of arrow 18; accordinyly, the ~ollowing set of
equations control operations:
(1) RLSP = REF-NP-TR
(2) END 1 = REF
(3) END 2 = REF-~GPNO~K-l
3~ If GPNO = 0
(4) GAP 1 = 0
(5) GAP 2 = 0
ïf GPNO > 0
(4) GAP 1 = REF^~GPLOC-l
(5) GAP 2 = REF+GPLOC+GPNO
(6) ROOM = TR-REF-GPNO^~l
-
01 -16-
Table II, below, deines the notations used
above in connection wi-th the Equation Set I:
05
TABLE :[I
Notation DEFINIT[ON
_ . _ _ ___
SEILO Eneryy source location
S~NO Eneryy source number
l0 REF Location of reference sensor
ROOM ~lo. of rollalong switch positions available
~or advanciny the clctive spread
TR Ground reference for recorder location
P~O Number of geophone yroups in the GAP
15 GPLOC Location of the GAP
K Number of data channels in recording system
(24, 48, 60, 96, 120, etc).
END 1 Ground location of the geophone yroup inter-
connected throuyh the rollalong switch to
the first data channel of the recorder.
END 2 Ground location of the Kth data channel
GAP 1 Ground locatlon of the data channel below
the GAP on the first data channe:L slde.
GAP 2 Ground location of the data channel above
the GAP toward the Kth channel.
RLSP Rollalong switch position required for a
desired active spread location.
NP Number of rollalong switch positions avail-
able minus 1. (N~ ollalong switch
must be configured for K-~N inputs and K
outputs.
GL(+) Ground location numbers along the seismic
line increasing numerically in the
direction in which the active geophone
array is advanced for each successive
record sequence
01 -17-
Notation DEFINIT~ON
.
GL(-) Ground locations numbers decreasing nurneric-
05 ally in the direction in which the active
spread is advanced.
CH(+) Seisrnic data channel increasing (1 to K)
numerically along the active spread in
the direction in which the active spread
is ac1vanced.
Ci~( ) Seismic data channels numerically decreasiny
(from K to 1) in the direction in which
the active spread is advanced.
GAP 2 Ground location of the data channel above
the GAP toward the Kth channel.
RLSP Rollalong switch position required for a
desired active spread location.
NP Nurnber of rollaloncJ switch positions avail-
able minus 1. (N-l). Rollalong switch
must be configured for K-~N inputs and K
outputs.
GL(+) Ground location numbers along the seisrnic
line increasing numerically in the
direction in which the active qeophone
array is advanced for each successive
record sequence
GL(-) Ground locations numbers decresing numeric-
ally in the direction in which the active
spread is advanced.
CH(+) Seismic data channel increasing (1 -to K)
numerically along the active spread in
the direction in which the active spread
is advanced.
CH(-) Seismic data channels numerically decreasing
(from K to 1) in the direction in which
the active spread is advanced.
0l -18-
rlote that the signs (~ ) of each of the
ground location numbers (GL) signifies its relationship
05 with respect to the direction of the array advance; thel
reference sensor ancl the sign of the channel nwnber are
also dependent on the array reference status. t~ the
latter is l, the CII is positive. [f not, then the sign is
negative.
SEQUENCE START_EQUA'rION SET II
~ith the ground location numbers increasing but
the channel numbers decreasiny, the following set oE equa-
tions is used:
(l) RLSP = 'I'R-REF-GPNO+l
(2) END 1 = REF+GPNO~K-]
(3) ENn 2 = REF
If GPNO = 0
(4) GAP l = 0
(5) GAP 2 = 0
If GPNO > 0
(4) GAP 1 = END l-GPLOC-l
(5) GAP 2 = END l-GPLOC-GPNO
(6) ROOM = TR-REF-GPNO.
SEQUENCE START EQUATION SET III
.. . .
With ground location numbers decreasing but the
channel numbers increasing, the following set of equations
is used:
(l) RLSP = TR-~NP-REE`
(2) END 1 = REF
(3) END 2 = REF-(K-l)-GPNO
If GPNO = 0
(4) GAP l = 0
(5) GAP 2 = 0
If PPNO > 0
(4) GAP l = REF-GPOC-l
(5) GAP 2 = REF-GPLOC-GPNO
(6) ROOM = REF-TR-GPNO+l
3~
01 -19-
SEQ_INGE s-TA~T-EQuAlrIoN SEr_IV
With both ground location nurnbers and channel
05 numbers decreasing, the followiny set of equations is
used:
(1) RLSP = REF~'t'R-GPNO~l
(2) END 1 - REI;`-(K~ GPNO
(3) END 2 = ~EF
If GPNO = 0
(4) GAP 1 = 0
(5) G~P 2 -- 0
If GPNO > 0
(4) GAP 1 = END l+GPLOC-l
(5) GAP 2 -- END l~GPLOC~GPNO
(6) ROOM = REF-TR-GPNO
~ollowing these operations, the operator peruses
the data at displays 27 and the encoders 26. If it is
correct, he activates the trigger switch 61 (FIG. 4) to
ultimately cause the energy source 16 (FIG. 1) to be
activated. But before that can run, there is transference
of all pertinent header data to the digital field
recorder 21 in the manner of FIGS. 3 and 10. Note in FIG.
10, that after the operator activates the firing switch
61, the DFS 10 generates a series of commands to the
recorder 21 which executes them in the manner shown.
I.e., the tape drive of the recorder 21 first accelerates
the tape past the recording head until nominal operating
speed is achieved. Then, regular header data is recorded
on the tape at time Tl-T2. Note at time T2, the data
associated with selected encoders 26 and displays 27 are
next transferred in the manner depicted in FIG. 8 in which
I/O array 34 enables the above "selected" elements to pass
the associated data. That is to say, array 34 is capable
of enabling displays 70-73 and encoders 48-53 so that data
can be transferred via bus 80 and header interface 81 to
the recorder 21. Address multiplexer 78 is used to
~0 generate the prerequisi-te format in conventional
01 -20-
fashion. As a result, annotatlon of spread and source
position associated with subsequently collected seismic
05 data, is assured. (Note from FIG. 9E that the controller
20 ls placed in an inhibited mode of operation durinq the
recording of header data. Thus, if there are inadvertent
chanyes in the controller status during the recordiny
thereof, they do not affect operations.)
It should be noted tha-t the address multiplexer
7~ preferably formats the data using standard guidelines
adopted by the SEG Technical Standards Subcommittee on
Tape E'ormats, in the manner of FIG. 7.
DATA ARRANGEMENT AT RECORDER 21
As shown in FIG. 7, header segment 79 has 2x2
array dimensions that are sixty-four (64) bytes by nine
(9) characters wide. Organization of each byte include
two 4-bit BCD segments utilized to indicate: line
direction, group interval, shot depth, shot offset, offset
direction, charge size, shot location, shot number, truck
location, end group location, gap groups locations and
associated data channel, in the order shown. As a result,
adequate documentation of spread and source locations for
annotation purposes, is assured.
~5 It should be understood that the invention is
not only directed to the specific embodiments set forth
above, but that many variations are readily apparent to
those skilled in the art, so thus the invention is to be
given the broadest possible interpretation within the
terms of the following claims.
