CA1168341A - Method and apparatus associated with a microcomputer system for automatically indicating and recording parameters that spatially define locations of seismic exploration spread and source arrays - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention relates to a method and apparatus for selectively providing (i) an alarm-generat-ing 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; (ii) a next-in-time positional code for disconnectably 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; and (iii) for conditionally updating source-detector array parameters related to a seismic exploration system, especially during generation and collection of seismic data using a vibratory source detec-tor array positioned at known locations along a line of survey at the earth's surface.

Description

METHOD AND APPARATUS ASSOCIATED
WITH A MICROCOMPUTER SYSTEM FOR
AUTOMATICALLY INDICATING AND RECORDING
PARAMETERS THAT SPATIALLY DEFINE LOCATIONS

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 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 .

_3_ 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 -3~-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, ~ . -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;

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, 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~

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~

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 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.

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~

(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.

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,.~

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 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.

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.

Claims (18)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Method of selectively providing an alarm-gener-ating digital code so as to alert an operator that a next-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:
(a) 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 collec-tion cycle, whereby an alarm-generating digital code can be selectively provided, for warning purposes.

2. Method of Claim 1 in which step (b) is further characterized by the substeps of (i) if said difference is greater than zero, no alarm-generating code is provided but (ii) if said difference is zero, said alarm-generat-ing code is activated.

3. A ground position controller for 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 microcom-puter system comprising an MPU, memory units and a series of display/storage and switching devices interconnected via a system bus, said MPU including means for separately determining the difference between (i) the maximum number of detectors or detector groups accommodated by a fixed roll switch matrix size during collection 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.

4. Controller of Claim 3 in which said display/storage and switching devices include a separate display means for alerting purposes.

5. 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 for generating and collecting seismic data associated with an earth formation underlying said array, said rollalong switch being employed to efficiently connect (and discon-nect) different but contiguous sets of detectors of said array from amid a plurality of detectors, along said line of survey, said next-in-time positional code being simul-taneously generated along with additional next-in-time array parameters associated with said exploration 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 sig-nal, 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 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.

6. Method of Claim 5 in which said roll switch update signal is automatically generated by said DFS as an end-of-record signal.

7. Method of Claim 5 in which said roll switch update signal is manually generated by activating a switching means of one of said display/storage and switching devices of said microcomputer system.

8. Method of Claim 5 in which said positional code is transmitted as a stepping pulse code, one bit pulse at a time, and said code is terminated when a feedback signal indicative of roll switch position matches said generated next-in-time positional code.

9. 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 of seismic data by a source-detector array positioned at known 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 posi-tional code being generated as bits of digital data using 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, 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 known locations along said line of survey, (c) generating and transmitting a step pulse code in association with said position code, (d) indicating at one of said display/storage 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 microcomputer system.

10. Method of Claim 9 in which said step pulse code of step (c) is generated a pulse at a time, and said termination of switch advance of step (e) only occurs when a final stepping pulse causes a generated feedback code indicative of roll switch position by said rollalong switch to be compared favorably with said generated next-in-time positional code.

11. A ground position controller for generating a next-in-time positional code simultaneously with generat-ing next-in-time 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, said next-in-time positional code controlling a rollalong switch in opera tion 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, explora-tion and next-in-time rollalong switch parameters that allow repetition in sequence of activities along said line of survey, separate display means for automatically dis-playing at least a portion of said encoded data including incremental and final rollalong switch position in alpha-numeric form for operator examination and for correction, if required.

12. Controller of Claim 11 in which said microcompu-ter system includes an audio-alarm tied to and actuated by said microcomputer system via said system bus, on the occurrence of a roll switch matrix position change.

13. Controller of Claim 11 in which said MPU
includes a counter operatively connected to said rollalong switch for providing for comparison, in real time, of the desired, next-in-time switch parameter, with the actual switch position.

14. 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 (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 sys-tem bus, comprising:
(a) after an interrupt request has been generated by said microcomputer system automatically determining roll switch status whereby source type is identified, (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 exploration cycle is beginning, followed by incrementing of a shot number counter at one of said series of display/storage and switching devices of said system, (c) if the switch is in a disabled state signifying that an impulsive soure is in use in which a single activator per what location occurs, after determining roll direction, calculating via said microcomputer system (i) new spread end positions for next-in-time source activation, (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.

15. Method of Claim 14 in which the step of deter-mining roll switch status includes checking bi-state status of separate switch means associated with said series of display/storage and switching devices of said microcomputer system.

16. A 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 posi-tion 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 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 and exploration parameters that allow repetition in sequence of activities along said line of survey, sepa-rate 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, and separate switch means connected to said microcomputer system for determining, on command, roll switch status whereby source type is identified and operational update sequence determined.

17. Controller of Claim 16 in which said microcompu-ter system includes an audio-alarm whose operation is dependent upon switch state (ONE, ZERO) of said separate switch means of said series of display/storage and switch-ing devices, whereby if a vibratory source is used, the start of each sweep cycle is audibly indicated.

18. Controller of Claim 17 in which said display/storage and switching devices of said microcompu-ter system also includes a sweep count indicator whose operation is also dependent upon switch state of said separate switch means.