Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD AND APPARATUS ASSOCIATED
WITH A MICROCOMPUTER SYSTEM FOR
AUTOMATICALLY INDICATING AND RECORDING
PARAMETERS THAT SPATIALLY DEFINE LOCATIONS
5 OF SEISMIC EXPLORATION SPREAD AND SOURCE ARRAYS
FIELD OF THE INVENTION
This invention relates to an improved method and
apparatus for providing control of ield shooting and
recording operations during exploration of hydrocarbons,
or the like.
Related Applications
My following commonly assigned application is:
Canadian Serial No. 381,818 filed July 15, 1981
for "Ground Position Controller and Method for Automatically
Indicating and Recording Parameters that Spatially Define
Locations of Seismic Exploration Spread and Source Arrays".
BACKGROUND OF THE INVENTION
While the above-identified ground position con-
troller and method of my related application provides for
automatic generating, formatting, displaying and recording
of seismic information (including next-in-time sensor and
source array geographic locations), additional operational
problems remain.
E.g., as the source-detector array is being
sequentially advanced along a line of survey, modifica-
tions must he made -to the input parameters lof the ground
position controller) during operations, especially where
the array has advanced to its fullest extent,
location-wise, vis-a-vis a fixed recording truck-roll
switch start position associated with a key position of
the "active" array of detectors along the line of survey.
Another problem area of note: modifications must also be
made where the operations of the controller are inter-
locked with changes in switch matrix length of a conven-
tional rollalong switch. (The latter switch of course isemployed to disconnectably connect recording circuitry to
~ ", 'b~ ; ~6
01 -2-
different (but contiguous) sets of detectors, i.e., an
- "active" array, from among a plurallty of detectors posi-
tioned along the line of survey.)
Still another problem area: if the seismic
source used to generate seismic waves is a vibrator type,
still further modifications must be made to the irlput
parameters (of the position controller) each shooting
cycle to indicate that the source is being vibratorily
swept a particular selected number of times without change
in its position along the line of survey.
SUMMARY OF THE IN~IENTION
The present invention relates to a method and
apparatus for selectively providing an alarm-generating
digital code so as to alert an operator that the next-
in-time positions of a source-detector array are the last
approved locations before the recording truck location
must be changed, i.e., "rolled forward" a predetermined
distance along the line of survey and array parameters re-
normalized. The alarm-generating data are produced along
with other conventional next-in-time array parameters as
bits o~ digital data using a microcomputer system opera-
tionally connected to a digi-tal field system (DFS) within
the recording truck through a system bus. The data of
interest are provided only, however, on the occurrence of
a situation in which the number of source-detector posi-
tions to be "rolled forward" is equal to or greater than a
maximum approved group number stored within the microcom-
puter system. Audio and/or visual alarms are then
triggered.
In another aspect, the present invention selec-
tively generates a next-in-time positional code for dis-
connectably connecting recording circuitry to different
but contiguous sets of detectors, i.e. an "active" array,
from among a plurality of detectors positioned along the
line of survey. Such positional code is generated along
with other next-in-time source-detector array parameters
based on, say the occurrence of an operations signal
generated by circuitry associatecl with a digital field
.
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system (DFS). For this purpose the system bus is con-
nected (via a port) to a rollalong switch. The positional
code generating system also features closed loop control
to insure that the final position of the switch is the
correct one.
In yet another aspect, the present invention
conditionally updates source-detector array parameters
related to a seismic exploration system, especially during
generation and collection of se:ismic data using a vibra-
tory source positioned at a known location along a line ofsurvey at the earth's surface. ~f the sweep count is
below the maximum encoded count, the next-in-time array
positions are not generated nor displayed. The sweep
count counter is updated, however, each operating cycle.
Finally, when the sweep count matches the maximum count,
new positional data for subsequent operations are gene-
rated and displayed, for operator perusal.
Other aspects of this invention are as follows:
~ethod of selectively providing an alarm-
generating digital code so as to alert an operator that anext-in-time array position of a source-detector array
associated with a recording truck is the last approved
set of array locations, using a microcomputer system
that includes an MPU, memory units and a series of
display~storage and switching devices interconnected via
a system bus, comprising:
la) storing as data bits, information as to the
maximum number of detectors or detector groups accommo-
dated by a fixed roll switch matrix size associated with
said array;
(b) at the end of each seismic data collection
cycle, determining the difference between (a) and the
total number of detectors or detector groups that will
have been employed at the end of the next-in-time
collection cycle, whereby an alarm-generating digital
code can be selectively provided, for warning purposes.
,, ~ ~,
~3a-
A ground position controller fo:r selectively
providing an alarm-generating digital code so as to alert
an operator that next-in-time array positions of a
source-detector array associated with a recording truck
is the last approved set of locations, including a
microcomputer system comprising an MPU, memory units and
a series of display/storage and switching devices inter-
connected via a system bus, saicl MPU including means for
separately determining the diffe.rence between (i) the
maximum number of detectors or detector groups accommo-
dated by a fixed roll switch matrix size during collec-
tion of seismic data and (ii) the total of detectors
or detector groups that will have been employed at the
end of the next-in-time collection cycle, whereby an
alarm-generating code for warning purposes, can be
selectively provided.
Method of controllably providing a next-in-time
positional code for a rollalong switch of a digital field
system of an exploration system that includes a source-
detector array positioned along a line of survey forgenerating and collecting seismic data associated with
an earth formation underlying said array, said rollalong
switch being employed to efficiently connect (and dis-
connect~ different but contiguous sets of det~ctors of
said array from amid a plurality of detectors, along
said line of survey, said next-in-time positional code
being simultaneously generated along with additional
next-in-time array parameters associated with said explo-
ration system, by a microcomputer system that includes
an MPU, memory units and a series of display/storage and
switching devices interconnected to each other and to
said DFS via a system bus, comprising:
(a) on being commanded by a roll switch update
signal, establishing in digital format said next-in-time
positional code for said rollalong switch,
(b) transmitting said code to said rollalong
switch while simultaneously indicating via audio and/or
-3b-
visual signals, that transmission of said next-in-time
code is occurring,
(c) terminating transmission of said code when a
correct rollalong switch position is attained.
A method of generating a next-in-time positional
code simultaneously with generating next-in-time array
and source parameters related to an exploration system
during generation and collection oE seismic data by a
source-detector array positionecl at known locations along
a line of survey, said next-in-time positional code con-
trolling a rollalong switch in operation contact with
said array by selective change in switch matrix position,
said positional code being generated as bits of digital
data using a microcomputer system that includes a micro-
processor unit (MPU), memory units and a series ofdisplay/storage and switching devices interconnected to
each other and to a digital field system (DFS~ via a
system bus, comprising:
(a) after a roll switch updating signal has
been received, establishing via said microcomputer
system, said next-in-time positional code for said
rollalong switch,
(b) determining up or down roll direction of
switch matrix advance with reference to at least one of
said ~nown locations along said llne of survey,
~ c) generating and transmitting a step pulse
code in association with said position code,
(d) indicating at one of said display/s-torage
and switching devices of said microcomputer systems
audio and~or visual signals denoting the occurrence of
(c),
(e) terminating (c) when the final position
of the roll switch matches that associated with the
generated next-in~time positional code of said micro-
computer system.
A ground position controller for generating anext-in-time positional code simultaneously with gene-
rating next-in-time array and source parameters rela-
ted to an exploration system during generation and
-3c-
collection of seismic data by a source-detector array
positioned a-t ~nown locations along a line of survey, said
next-in-time positional code controlling a rollalong
switch in operation contact with said array by selective
change in switch matrix position, said positional code
being generated as bits of digital data, comprising a
microcomputer system that includes 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
and storage devices including separate encoding means
for automatically encoding digital data related to array
geometry, exploration and next-in-time rollalong switch
parameters that allow repetition in sequence of activi-
ties along said line of survey, separate display means
for automatically displaving at least a portion of said
encoded data including incremental and final rollalong
switch position in alphanumeric form for operator
examination and for correction, if required.
A method of conditionally updating array and
source parameters related to an 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 in operational contact
with a rollalong switch capable of changing switch matrix
size and hence "active" detector position on command,
based no type of source being used by said exploration
system, said updated parameters being generated as bits
of digital data in a microcomputer system that includes
a microprocessor unit lMPU~ 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, comprising:
(a) after an interrupt request has been gene-
rated by said microcomputer system automatically deter-
mining roll swi.tch status whereby source type is identi-
fied,
~3.
~3d-
(b) if said rollalong switch is in enabled state
designating a vibratory source is being used in said
exploration system, enabling an audio alarm to alert a
human operator that an explorat:Lon cycle is beginning,
followed by incrementing of a shot number counter at one
of said series of display./s-torage and switching devices
of said system,
(c) if the switch is iIl a disable state signify-
ing tha~ an impulsive source is in use in which a single
activator per what location occur.s, after determining roll
direction, calculating via said microcomputer system (i)
new spread end positions for next-in-time source activa-
tion, (ii) new gap positions for said spread, and (iii)
a new rollalong switch position,
(d) displaying the data of (c) in alpha-numeric
form at one or more of said series of display/storage and
switching devices of said microcomputer system, for
operator examination and for correction, if required.
~ ground position controller for manipulating,
calculating, storing, and conditionally updating array
parameters 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, in operational
contact with a rollalong switch capable of changing
switch matrix size and hence "active" detector length
and position on command based on source type, said updated
data being generated as bits of digital data comprising
a microcomputer system including a microprocessor unit
(MPU), memory units, and a series of displaylstorage and
switching 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 o~ activities along said line of survey,
separate display means for automatically displaying at
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least a portion of said encoded data in alpha-numeric
form for operator examination and for correction, if
required, and separate switch means connected to said
microcomputer system for determi.ning, on command, roll
switch status whereby source type is identiied and
operational update sequence determined.
DESCRIPTION OF T~!E DRAWINGS
.,
These and ot~er functions of the present inven-
tion will become evident to -those skilled in the art
from a reading of detailed descriptions embodiments there-
of, following a brief description of the appended drawings.
FIGS. 1 and 2 illustrate an exploration system
incorporating the present invention in which a source of
energy and an array of sensors connected to a recording
truck, are illus-trated.
FIGS. 3, 4, 5 and 6 are diagrams of certain
aspects of a microcomputer system and controller of the
present invention used within the exploration system of
FIGS. l and 2.
FIGS. 7A-7E and 8-10 are flow diagrams which
illustrate the method of the present invention.
DESC~IPTION OF PREFERRED
EMBODIMENTS OF T~E INVENTION
.
FIG. l illustrates operation of seismic explora-
tion system 9 of the present invention.
As shown~ system 9 includes digital field system
(DFS) 10, housed within recording truck 11 and
01 _~_
electrically interconnected via a mul-tiwire geophysical
cable 12 to an array of sensors 13 positioned at the
earth's surface 14. Ground locations 15 are represented
as surrounding both the array of sensors 13 and seismic
energy source 16, all positionecl alony the surface 1~. As
previously mentioned in the CDPR collection process, the
ground locations 15 would, more likely than not, have been
previously surveyed prior to implementation of the seisrnic
surveying operation along the line of survey 17 in the
direction oE arrow 1~. Hence, each of the locations 15
can be designated by a particular position number (or P
number) alony 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
collected) is identified by the sequence numbers N, N+l...
N+M designating the leng-th of the active array as the
sensors 13 are advanced in the direction of arrow 18.
~0
Annotating the positions of the sensor arrays is
aided by the fact that each sensor is associated with a
particular data channel 1, 2...K of the DFS 10 as the data
is collected. For usual operations K can be 24, A8, 60,
96, 120, etc., as required, although, of course, the pre-
sent invention is not limited to a particular channel
capacity number, but can be varied to accommoda-te any
field arrangement. Each sensor position and each source
location can be indicated using the ground position con-
troller ~0 of the present invention in conjunction with
recording unit 21 of the DFS 10.
FIG. 2 illustrates ground position controller 20
in more detail.
Briefly, the ground position recorder 20
3 operates in the field to insure integrity between pre-
scribed and actual field shooting and recording operations
by a series of steps, namely, storing, manipulating and
displaying data related
(i) to field positions of the source and sensor
array by position number,
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01 _5
(ii) to array and source geometrical locations
(both present and next-in-time) based on field geometrical
algorithms and
(iii) to recording array and source parame-ters
so that realistic annotation of the subsequently collected
seismic data can be made. For these purposes, the opera-
tor utilizes encoded data provided initially by him using
encoders 26, manipulated results generated by the contro]-
ler 20 based on part in stored relationships within the
microcomputer 25, and finally indicating geometrical data
set forth at displays 27 and as header information at
recording unit 21.
Since the present inventio~n deals conveniently
with the CDPR process, the array oE sensors 13 and source
of energy 16 are continually "rolled forward" in the
direction of arrow 18 using rollalong switch 22. That is
to say, after the seismic data has been recorded at the
digital tape recording unit 21 (after amplification by
amplifier 24), the array of sensors 13 (and source 16)
located at a first series of positions P as shown, are
"rolled forward" in the direction of arrow 18. Note that
the changing of the active array pattern of FIG. 1 in the
aforementioned manner is identified by the array sequence
designated N, N+l... N~M, as previously mentioned. But,
the array and source geometry is always known at the
recording truck 11 provided the positional locations 300,
3 301, 302... P of FIG. 1 for the particular active array N,
N+l... N~M are correctly identified and recorded during
each recording cycle, via operation of the ground position
controller 20 of the present invention; of particular
importance is the manlpulation of data associated with the
field geometry of the sensors 13 and source 16 via geo-
metrical and performance algorithms stored within micro-
compu-ter 25 of the controller 20.
As previously mentioned, microcomputer 25 is
used to preclict correct array positions as the rollalong
switch 23 switches between "active" and "inactive" arrays
of sensors. The microcomputer 25 can also interact with
01 -6~
the rollalony 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
long Switch", by Input-Output, Inc., Houston, Texas, and
consists oE a series of contacts 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
(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
digital generator (not shown) for generating a second
multi-bit code indicative of the position P of a member of
the sensor array as header indicia at the recorder 21.
However, as previously mentioned, the latter digital code
represents only an arbitrary number and is not a true
geodytic location.
FIG. 3 illustrates microcomputer 25 of con~
troller 20 in still more detail.
As shown, the microcomputer 25 includes a system
bus 28 used to connect encoders 26 and displays 27 via I/O
interrupt array 34 to microprocessor unit 30 ~MPU) of the
microcomputer 25. ~lso connected via the bus 28 and ports
29 are interrupt controller 31, RAM 32, P~OM 33 (in addi-
tion to I/O interfacing array 34) which operates in con-
ventional ~ashion to calculate, manipulate, store and
display position data associated with the exploration
operation. Note that the I/O array 34 not only links the
MPU 30 with 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.
~us 28 essentially comprises three separate
buses, a data bus, an address bus and a control bus. The
data bus is conventional: it not only carries information
3~.~
Ol _7_
to and from MPU 30, but it is also used to fetch instruc-
tions that have been storecl in ROM 33, as required, as
well as carries data from/to the encoders 26 and displays
27 of FIG. 2, by way of (or independent of) R~ 32.
Addressing segments of the data is the annota-
tions function of the address bus. It is capab:Le of
selecting a location in R~ 32 or ROM 33 or a particular
address in the MPU 30 when appropriately siynaled, say by
interrupt controller 31. The control bus controls the
sequencing and nature of the operation using common selec-
tor commands, e.g., "Read", "Write", etc.
Additionally, it should be noted, the system
interrupts are usually carried via the control bus to
implement the scheduling and servicing of different ports,
as required by operations. In the present invention,
interrupt controller 31 handles seven (7) vectored prior-
ity interrupts for the MPU 30, as explained below, includ-
ing an end-of-record interrupt ( EOR) generated by the
digital field system 1~, FIG. 1, to indicate the end of
the collection cycle, and to initiate operations in the
next-in~time cycleO
In general, in servicing the interrupts, preser-
vation of program status is required and i.s easily carried
by the MPU 30. Since the controller 31 is both vectored
and priority oriented, it has the responsibility of pro-
viding vectored interrupts to the MPU 30, of identifying
the nature of the interrupt, (or its branching address)
and of establishing priority between competing interrupts.
In particular in servicing the EOR interrupt, -the steps
set forth in EIGS. 9B and 9D are executed to bring about
automatic updating of the array and source geometry to
achieve the next-in-time collection of data, based in part
on the field algorithms contained in equation sets I, II,
III or IV set forth below.
FIG. 4 illustrates the nature of the data
provided at encoders 26 and displays 27.
The operator initially calibrates positions of
the exploration array and source with previously surveyed
3 ~
01 _~_
- geographical stations. Inforrnation has been already
encoded via the encoders 26 for use by microcomputer 25
before operations begin. Encoded 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 ~1;
(iii) reference station location (where the end
of the spread is initially positioned) encoded via encod-
ing sub-element 42;
(iv) initial location of the energy source
encoded using encoder sub-element 43;
(v) the number of shots or sweeps encoded at
sub-element 44;
(vi) the initial gap posi-tion, stored at sub-
element 45;
(vii) the gap spacing encoded using encoder sub-
element 46; and
(viii) gap roll increment encoded usiny sub-
element 47.
The operator also has the initial responsibilityof encoding other data which, for the most part, does not
change during the survey. In this regard, the operator
may have to only initially encode shot depth and size (at
sub-elements 48 and 49), shot direction and offset (at
sub-elements 50 and 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. Da-ta provided by these
switch arrays, relate to two or three possible switch
states oE the switches 56-66 which are, for example, rela-
ted 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;
01 _9_
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~ spec:ifies operations in
either a serial or in a paralLel mode, the mode bein~
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 Eunctions respective:Ly; switch 59, o~ course,
initializes operations after all synchronization has been
completed; switch 60 turns oEf 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
source positions as displayed at displays 27; switches 62
and 63 related to (i) the "trigger" link associated with
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 sta-te. Three-position
switch 64 establishes whether or not the operation is to
be in a manual, automatic or test mode; update switch 65
operates only when the switch 64 is in the manual mode and
is used (in manual mode) to initiate advances of the roll
switch so as to generate new ground locations for the
array after the recording cycle has been completed; and
switch 66 is a conventional power-on switch.]
Displays 27 may be conventional LED segmented
displays except that they are microcomputer implemented.
Primary purposes of the displays 27: to provide data to
the operator so that determinations as to whether or not
the system is functionin~ correctly can be made, and to
allow the operator to act as an independent cross-checker
of the correctness oE the displayed ground locations. The
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 oE shots per location, respectively;
01
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subdisplays 72-75 relate to geographic locations of the
active array as a function oE time; subdisplay 76 speci--
05 fies the position of the slave reference; status subdis
play 77 specifies (by code) the occurrence of certaln
activities during the e~ploration operation which may be
accompanied by an audio alarm to indicate the imrnecliate
need for operator intervention, the meaning of the status
code at subdisplay 77 being as set forth below, in
Table I.
TABLE I
Code Activi~y
0 Setup for sequence start operation
1 Geometrical mistie
2 Ready for update or update in progress (if
in auto mode)
3 Roll Switch Moving
~ Roll Switch (Stopped in position)
Roll Switch Disabled
6 Slave Reference Code Received
7 Transmission Reference Error (slave
reEerence code not received)
8 Load Ref Output At Shift Register
9 Transmit (one bit of ref code)
A Gap Set Mistie
D Occurrence of Last Shot
lX Beeper On With Status Displayed as to Code
0, 1, ... g, A, D, alone.
53 Step Roll Switch Up 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. Sequencing start button 59 terminates the cueing
operation; status code "D" indicates that the last shot
position is at hand and thus, the truck location and
01 ~11-
connection station vis-a-vis the array must be changed;
status codes "3", "4", "5" and "53" and "93" indicate
certain roll switch activities. If there are errors in
the programmed exploration activity, warniny codes are
also generated by the status codes "l"; and "7".]
OP~R~rION~L SEOUENCE
Assume the operator has initially calibrated the
start-up positions of the array and source with the sur-
veyed locations. As previously indicated in regard to
FIG. 4, this entails encoding of posi-tional data via
encoders 26 in con~unction with proper setting of the
switching arrays 5~, 55. The result: corresponding shot,
spread and associated data appear at the displays 27 due
to the interaction of data relationship established
through operation of the microcomputer 25 of FIG. 2. In
order to better understand how the present invention uses
all data, perhaps a brief overview of the hardware aspects
of the microprocessor 30 is in order and is presented
below in connection with FIG. 5.
It should be initially noted that MP~ 30 is
preferably an Intel 8085 microprocessor, a product of
Intel Incorp., Cupertino, California. ~s is well known,
it has a microprocessor and controller integrated into a
single 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 dedicated uses; the other registers, such
as accumulator 88, have more general uses. In the 8085,
expanded control functions resu]t because the low-eight
(8) address bits have the capability of being multiplexed.
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. 6.
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,
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it preferably comprises a multiplicity of 8-bit I/O port
chips independently addressable vla ALE line 89 of FIG. 5
of the MPU 30. Each 8-bit I/O port chip preferably com-
prises an ~-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 clata using known geometrical
relationships in which encoded positional data can be
translated as required, depending on several factors.
UPDATE AND ALERT SEQUENCE
.. . . . _ _ _
The foregoing operations assume that the opera-
tor has encoded all pertinent data via the encoders 26;
that switch arrays 54, 55 have been~properly set; and that
the next-in-time array positions of the generated
next-in-time data are approved locations.
Initially the control and reference location
position data from encoders 26 (and the switch arrays) are
fetched by the MPU 30. The MPU 30 next performs the
required manipulation of that data to provide spatial
array and source geometries of interest in the manner of
FIGS. 7A-7D; it also provides for the generation of an
alarm-indicating code in the fashion of FIGS. 7E and 8 as
well as for the generation of a roll switch position code
in the manner of FIGS. 9A-9C. While manipulation of data
without and within the MPU 30 including
(i) the execution of the power-up routine of
FIG. 7A;
(ii) the triggering of the system update
routine via FIG. 7B;
(iii) the execu-tion of the sequence start
routine of FIG 7C;
(iv) the triggering of the alternate manual
update routine of 7D, are all of some importance, the dual
generation of the alarm-indication code of FIG. 8 and of
the roll position code of FIGS. 9A-9C can take on a some-
what greater significance in moment~to-moment field opera-
O tions. Hence, a brief description of the generation of
.
01 -13~
such codes is in order and is presented below with speci-
fic reference to FIGS. 8 and 9A-9C~
05
As shown in FIG. ~ note that at each occurrence
of the generation of next-in-t:ime array parameters in the
manner of FIGS. 7A-7D, additional inquires along the lines
of steps 100, 101, 102 and 103 of FIG. 8 are being per-
formed. Result: the operator is provided with the kno~-
ledge as to when the next-in-t:ime array positions are not
approved array locations.
Now, in more detail, as shown in step 100, the
MPU 30 determines first the difference between (i) the
maximum number oE detector/source groups available per
fixed truck location (or roll switch matrix size) and (ii)
the number of groups that will be "exhausted" after the
generation oE the next-in-time array parameters by the
system.
Next at step 101 the result of step 100 is ana-
lyzed to determine if the next-in-time array positions are
approved locations, say by determining if the result of
step 101 is (or is not) greater than zero. If the result
is greater than zero, i.e., the answer to the question
posed by decisional step 101 is affirmative, the process
then undergoes iteration via loop 104; on the other hand,
if the result of step 101 is zero, then the next-in-time
roll switch position is the last one available for seismic
collection purposes as indicated by the generation of an
alarm-indicating code for triggering an audio alarm (at
step 102) and for causing activation of a visual alarm at
step 103. This alerts the operator to the fact that,
after collection of data, the subsequent next-in~time
positions of the array along the line of survey will
require a change in
(i) the truck position and
(ii) the start roll switch matrix position
vis-a vis the resul-ting positions of -the series
of detectors along the line of survey. A portion of the
displays 27 of FIG. 4, of course, can be utili~ed for
alerting the operator to the above situation.
3~
01 -14-
Values of array parameters appearing at dis-
plays 27 of FIG. ~, including the selective alarrn~gener-
ating code of FIG. 8, are, of course, dependent upon use
of certain geometrical equation sets, viz. equation sets
I, II, III and IV set forth below, stored in the MPU 30
and selectively utilized by the con~roller 20 as required.
SEQUENCE START EQUATION SET I
Assume both the ground location numbers and data
channel numbers increasiny alony the seismic line in the
direction of arrow 18; accordinyly, the followiny set of
equations control operations:
(1) RLSP = REF-NP-TR
(2) END 1 = REF
(3) END 2 = REF+GPNO-~K-1
If GPNO = 0
(4) GAP 1 = 0
(5) GAP 2 = 0
If GPNO > 0
(4) GAP 1 = REF-~GPLOC-l
(5) GAP 2 (N) = GAP 2 (N-l)+Roll
(6) ROOM = TR-REF-GPNO+l
Table II, below, defines the notations used
above in connection with the Equation Set I.
TABI.E II
Notation DEFINITION
SHLO Eneryy source location
SHNO Eneryy source number
REF Location of reference sensor
ROOM No. of rollalong switch positions available
for advanciny the active spread
TR Ground reference for recorder location
PNO Number of geophone yroups in the GAP
GPLOC Location of the GAP
K Number of data channels in recording system
4 (2~, ~8, 60, 96, 120, etc).
.
a
01 -15-
END l Ground location of the geophone group inter-
connected through the rollalong switch to
05 the first data channel of the recorder.
END 2 Ground location of the Kth data channel
GAP l Ground location of the data channel below
the GAP on the first data channel side.
GAP 2 Ground location of the data channel above
the GAP toward the ~Cth channel.
RLSP Rollalong switch position required for a
desired active spread location.
NP Number of rollalong s~itch positions avail-
able minus l. (N~l). Rollalong switch
must be conEigured for K+N inputs and K
outputs.
GL(+) Ground location numbers along the seismic
line increasing numerically in the direc-
tion in which the active geophone array
is advanced for each successive record
sequence~
GL(-) Ground locations num~ers decresing numeric-
ally in the direction in which the active
spread is advanced.
25 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 l~ to 1) in the direction in which
the active spread is advanced.
Note that the signs (+) (-) of each of the
ground location numbers (GL) signifies its relationship
with respect to the direction of the array advance; the
reference sensor and the sign of the channel number are
also dependent on the array reference status. If the
latter is l, the CH is positive. If not, then the sign is
negative.
01 -16-
SEQUENCE START EQUATION SET II
With the ground location numbers increasing but
the channel numbers decreasing, the following set of equa-
tions is used:
(1) RLSP = TR-REF-GPNO~l
(2) END :1 = REF-~GPNO-~K-l
(3) END :2 = REF
If GPNO - 0
(4) GAP :L = 0
(5) GAP 2 - 0
IE 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:
(1) RLSP = TR-~NP-REF
(2) END 1 = REF
(3) END 2 = REF~(K-l)-GPNO
If GPNO = 0
(4) GAP 1 = 0
(5) GAP 2 = 0
If PPNO > 0
(4) GAP 1 = REF-GPOC-l
(5) GAP 2 = REF-GPLOC-GPNO
~6) ROOM = REF-TR-GPNO+l
SEQUENCE START EQUATION SET IV
. .
With both ground location numbers and channel
numbers decreasing, the followiny set of equations is
used:
~0
3 ~ Ç~ 3~
01 -17-
(1) RLSP = REF-TR-GPNO+l
(2) END 1 = REF-(K-l)-GPNO
05 (3) END 2 - REF
If GPNO = 0
(4) GAP 1 = 0
(5) GAP 2 = 0
If GPNO > 0
(4) GAP 1 = END l+GPLOC-l
(5) GAP 2 = END l-~GPLOC-~GPNO
(6) ROOM = REF TR-GPNO
Following these operations, the operator peruses
the data at displays 27 and the encoders 26. If it is
correct, he activates the trigyer switch 61 (EIG. 4) to
ultimately cause the energy source 16 (FIG. 1) to be
activated. But before that can occur, there is trans~
ference of all pertinent header data to the digital field
recorder 21.
With specific reference to FIG. 9C, note that
the generation of the next-in-time rollalong switch code
(and associated array parameters) can proceed in either
one or two loops: via loop 105A, as when the updatiny
sequence is automatically undertaken; or via loop 105B
under contrary circumstances. Note that the key to loop
selection is decisional step 106A where the state of mode
switch 64 (FIG. 4) is testedO :[f the mode switch 64 is in
an automatic response state, the occurrence of an end-of-
record (EOR) signal from circuitry associated with DFS 10
(FIG. 1) at step 106B causes the loop 105A to execute step
106C. A next-in-time roll position code is then
generated.
On the other hand, assuming mode switch 64 is ln
a contrary operating state, the loop 105B is caused to
execute step 10~C when manual update switch 65 (FIG. 4) is
engaged (at step 106D)~ In either case, the result is the
generation of a next-in-time roll position code via step
106C.
--18--
FIGS. 9A and 9B describe --in more detail-- how
the positional code for rolla:Long switch is generated.
~ s shown in FIG. 9A~ initial execution depends
on the answer provided by decisional step 107: if the
roll direction vis-a-vis the advancement of the detectors
increases numerically in the direction of each advance-
ment, i.e. in the "up" direction, then loop 108, including
steps 109 and 110, is executecl~ On the other hand, if the
roll direction is in the down direction, i.e. ground loca-
tions decrease numerically in the direction of array
advancement, then loop 111, including steps 112 and 113,
is executed.
FIG. 9B illustrates the main thrust of steps
109, 110 and 112 and 113 in still more de-tail.
Note in FIG. 9B that after a stepping pulse (for
the stepping motor of the rollalong switch) generated at
step 115, has been transmitted to the roll switch at step
116 and displayed at step 117, a selected time interval
must pass (at step 118) before iteration can occur, depen-
dent on the rollalong switch response characteristics. At
step 119, if the final --correct-- position of the switch
has not been reached, iteration via loop 120 occurs, (see
FIG. 3) indicating that the switch itself provides a
cross-checking code. Note that as the roll position code
is being generated, the results are displayed using a
portion of the displyas 27 of FIG. 4.
Values of array parameters appearing at displays
27 of FIG. 4, including the selective alarm-generating
code of FIG. 8, are, of course, dependent upon use of
certain geometrical equation sets, viz. equation sets I,
II, III and IV set forth below, stored in the MPU 30 and
selecti~ely utilized by the controller 20 as required.
The foregoing operations, of course, assume ti)
that the source 16, FIG. 1, is of the impulsive type, and
(ii) that changes in array and source parameters vis-a-vis
positions along the survey, occur --automatically--
through execution of a series of steps that comprises loop
105A of FIG. 9C.
~.3,.~
01
-19-
As shown in FIG. 9C, af-ter the answer at deci-
sion step 106A is a positive one (i.e., the tes-ting of
mode switch 64 of the switch matrix associated with
encoders 26 of FIG. 4, is affirrnative), step 106B is
executed. New array parameters are then generated say via
step 106C.
On the other hand, if mode switch 6~ is in an
opposite operating state (say state ZERO), step 106A exe-
cutes the loop in an opposite mode, say via entry into
loop 105B. Within the loop 105B there is an initial query
of the update switch status (viz, status of update switch
65 of FIG. 4) via decisional step 106D. If the answer to
step 106D is in the affirmative, then updating of the data
and the roll position code via step 106C occurs.
Since step 106C is used in the execution of both
loops 10~A and lo5s, a brief description of step 106C is
in order and is provided via FIG. 10.
As shown in FIG. 10, initial execution of step
106C depends on the answer provided at decisional step
127. If the answer provided by step 127 is in the affir-
mative, then loop 128 is entered; if the answer is in the
negtive, then loop 129 is executed.
In more detail loop 128 is entered, of course,
if and only if, the tested status of a particular element
of the switch array 55 is negative, i.e., that rollalong
switch 63 of FIG. 4 is in a disabled state. Such a state
is indicative of the use of a vibratory source in the
data-gathering operations (and secondarily, that the sweep
count maximum also encoded in the controller has not
occurred).
On the other hand, loop 129 is executed if and
only if, the roll switch status in the controller, is
positive, i.e., that the switch 63 of FIG. ~ is in an
enabled state~ Then as shown in FIG. 8, updating steps
130, 131, and 132 of the loop 2~ are executed in sequence,
using inter alia, the sets of equations A, B, C and D
~0 shown below. In more detail, note that the operational
sequence in loop 129 is conventionally dependent upon
01
-20-
common sign relationships and notations, but also note
that the solutions of each modified Equation Sets A, B, C,
and D do not require extensive annotation.
UPDATE SEQUENCE EQUATION SET A
For both the ground location numbers and data
channel numbers increasi.ng along the line o:E survey, the
following set of equations are used by the microcomputer
system of the present invention:
(1) RLSP (N) = RLSP (N l)-~Roll
(2) END 1 (N) = END :L (N-l)+Roll
(3) END 2 (N) = END 2 (N-l)+Roll
If GPNO = 0
(4) GAP ]. = 0 =~ GAP 2
If GPNO > 0
(4) GAP 1 (N) -- GAP 1 (N-l)~Roll
(5) GAP 2 (N) = GAP 2 (N-l)+Roll
(6) SHLO (N) = SHI.O (N-l)-~Roll
(7) SIINO (N) = 01
UPDATE SEQUENCE EQUATION SET B
.., .. .. _ _
- With the ground location numbers increasing but
the data channel numbers decreasing, the microcomputer
system uses:
(1) RLSP (N) = RLSP (N-l)-Roll
(2) END 1 (N) = END 1 (N-l)+Roll
(3) END 2 (N) = END 2 (N-l)+Roll
If GPNO = 0
(4) GAP 1 = 0 = GAP 2
If GPNO > 0
(4) GAP l (N) = GAP 1 (N-l)+Roll
(5) GAP 2 (N) = GAP 2 (N-l)+Roll
(6) SIILO (N) = SHLO ~N~ Roll
(7) SHNO (N) = 0L
UPDATE SEQUENCE EQUATION SET C
With the ground location numbers decrea.sing but
the channel numbers increasing, the microcomputer uses:
4~
0l -21-
(l) RLSP (N) = RLSP (N-l)-~Roll
(2) END l (N) = END l (N l)-RolL
05 (3) END 2 ~N) -- END 2 (N-l)-Roll
If GPNO - 0
(4) GAP l = 0 = GAP 2
If GPNO > 0
(5) GAP 2 (N) a GAP 2 (N~ Roll
(6) Sl-lLO (N) = SHLO (N-l)-Roll
(7) SHNO (N) = 01
UPDATE SEQUENCE EQUATION SET D
For both ground location and data channel num-
bers decreasing, the microcomputer system uses:
(l) RLSP (N) = RLSP (N-l)-Roll
(2) EMD l (N) = END l (N l)-Roll
(3) END 2 (N) = END 2 (N-l)-Roll
If GPNO = 0
(4) GAP l = 0 = GAP 2
If GPNO > 0
(5) GA~ 2 (N) = GAP 2 (N-l) Roll
(6) SHLO (N) = SHLO (N-l)-Roll
(7) SHNO (N) = 0l
Note that the microcomputer system 25 operating
in an update sequence will, in addition to solving the
appropriate equations, also update the status of the num-
ber of roll switch positions (ROOM) available for advanc-
ing the array. In the event that ROOM = 0 following an
update command, the LAST SHOT status light can be
activated. This informs the operator that the active
spread cannot be further advanced unless the present loca-
tion of the recording truck is changed. It should be
noted that if decision loop 129 of FIG. l0 is entered
using the microcomputer system 25, the latter does not
execute instructions associated with equation sets A, B, C
or D but instead it executes instructions in the manner of
steps 134, 135 and 136, using selected portions of the
routines set forth in FIGS. 7A-7E, in the manner
indicated.
01 -22-
It should be understood that the invenkion is
not directed to specific embodiments set forth above, but
S 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.
