Patent Publication Number: US-2019179042-A1

Title: Portable seismic survey device and method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority of and is a continuation application under 35 U.S.C. § 120 based upon co-pending U.S. patent application Ser. No. 15/442,870, filed on Feb. 27, 2017. The entire disclosure of the prior application is incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present technology relates to a portable seismic survey system and method for use in connection with reflection seismology for mapping subterranean formations. 
     Background Art 
     It is known in the petroleum, gas, mineral and water exploration industries to use seismic geophysical surveys to map subterranean formations, such as but not limited to: stratigraphy of subterranean formations, lateral continuity of geologic layers, locations of buried paleochannels, positions of faults in sedimentary layers, basement topography, and others. These maps can be deduced through analysis of the nature of reflections and refractions of generated seismic waves from interfaces between layers within the subterranean formation. 
     Typically, a seismic energy source is used to generate seismic waves that travel through the earth and are then reflected by various subterranean formations to the earth&#39;s surface. At the surface, these reflected seismic waves are detected by an array of ground motion sensors, known as seismometers or geophones, which convert the detected waves into electrical signals. The electrical signals are stored and analyzed by a computer modeling system to determine and display the nature of the subterranean formations at a location surrounding the point the seismic waves were generated. 
     Known seismic energy source devices can be in communication with a global position system (GPS) or other telemetry systems to provide logging of the precise location and time of seismic wave generation. Typically, the seismic energy source device is controlled and activated automatically by the telemetry system, which can present a potential disadvantage since multiple error logs can occur by misfires of the seismic energy source device. Further disadvantage of these known systems is that the user does not having full control of the seismic energy source device since detonation is controlled by the telemetry system. 
     It has become desirable to extend drilling to locations that are environmentally sensitive or with limited vehicular access, which appear to overlay oil and gas formations. Thus portable seismic energy source devices have been developed and used. 
     It has been known to use vehicles that transport or tow a seismic source device from location to location. At a given location the seismic source is placed in direct contact with the ground. The seismic source device is activated to generate a seismic wave. However, the traditional seismic source devices are very heavy and thus need to be deployed by a vehicle, and they typically require large charges for creating a seismic wave that can travel deep through the Earth. As the environmentally sensitive areas prohibit or strictly limit the access of heavy duty equipment or vehicles, the existing methods for generating seismic waves are not suitable for these areas. These large systems are also undesirable for application in shallow wells that span large lateral distances. 
     Seismic data is critical to oil and gas companies during the exploration and development of oil and gas reserves. Seismic data is used from the earliest point in exploration right through the life of an oil or gas field, and in some cases even after the well has been abandoned. Seismic data is used for many different purposes; broad based analysis of prospective hydrocarbon basins, localized exploration of a prospective area, high resolution imaging prior to drilling a well, throughout the drilling process (including pore pressure prediction and micro-fracture analysis), and to enhance production as a field is developed and optimized throughout its productive life. 
     While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a portable seismic survey system and method that allows reflection seismology for mapping subterranean formations with detonation triggered event marking. 
     Therefore, a need exists for a new and novel portable seismic survey system and method that can be used for reflection seismology for mapping subterranean formations. In this regard, the present technology substantially fulfills this need. In this respect, the portable seismic survey system and method according to the present technology substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of reflection seismology for mapping subterranean formations. 
     BRIEF SUMMARY OF THE PRESENT TECHNOLOGY 
     In view of the foregoing disadvantages inherent in the known types of seismic source systems now present, the present technology provides a novel portable seismic survey system and method, and overcomes the above-mentioned disadvantages and drawbacks of known types of seismic source systems. As such, the general purpose of the present technology, which will be described subsequently in greater detail, is to provide a new and novel portable seismic survey system and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in a portable seismic survey system and method which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof. 
     To attain this, the present technology essentially includes a seismic survey device including an upper assembly, a firing pin operably associated with a firing pin actuator, a lower assembly including a cartridge holder, and a detonation sensor. The cartridge holder can have a configuration capable of retaining a blasting cartridge so that the firing pin is capable of operationally detonating the blasting cartridge. The detonation sensor is capable of detecting a detonation condition of the blasting cartridge. 
     At least one tube can be attached to the upper assembly, with the lower assembly attachable to the tube. The firing pin can be slidably receivable in the tube. 
     The upper assembly can further define an internal cavity and at least one longitudinal slot in communication with the internal cavity. The longitudinal slot can have a configuration capable of slidably receiving a portion of a sensor holding assembly. A portion of the detonation sensor can be associated with the sensor holding assembly. The firing pin actuator can be slidably received in the internal cavity. 
     The sensor holding assembly can include an actuator handle featuring the portion slidably receivable in the longitudinal slot. The actuator handle can define an actuator handle cavity with a configuration capable of receiving at least a portion of the detonation sensor. 
     The lower assembly can further include a firing chamber attachable to the cartridge holder. The firing chamber can define a firing chamber bore having a configuration capable of receiving therethrough a firing tip of the firing pin. The firing tip is capable of striking a primer end of the blasting cartridge to initiate detonation. 
     The firing chamber can further define an internal firing chamber cavity in communication with the firing chamber bore. The internal firing chamber cavity can have a configuration capable of receiving at least a portion of the cartridge holder. 
     There has thus been outlined, rather broadly, features of the present technology in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. 
     The present technology may also include a lower tube attachable to the tube and the firing chamber. The lower tube can include channels defined in an external surface thereof. 
     Still further, the present technology may include at least one foot support assembly and/or at least one handle. 
     Additionally, the cartridge holder may include a flanged end that can define radially arranged notches having a configuration capable of being engageable with a tool for rotation of the cartridge holder. 
     The present technology may further include at least one firing pin guide attachable to the firing pin. The firing pin guide can have a configuration capable of being slidably received in the tube or the lower tube. 
     According to one aspect of the present technology, the present technology essentially includes a seismic survey system including a portable device configured to create a seismic wave, at least one sensor, and an event marking device. The sensor can be configured to detect a creation condition of the seismic wave and to generate a signal associated with creation of the seismic wave upon detecting of the creation condition. The event marking device can be configured to receive the signal, to determine a time associate with the creation of the seismic wave, and a geographic location of the portable device upon triggering by receipt of the signal. 
     According to another aspect of the present technology, the present technology can include a method of using a seismic survey system. The method including creating a seismic wave at a geographic location utilizing a portable device. Detecting creation of the seismic wave using a sensor. Communicating a signal from the sensor to an event marking device. Triggering by receipt of the signal a recordation by the event marking device of a time associated with creation of the seismic wave and a geographic location of the portable device. 
     According to another aspect of the present technology, the present technology can include a method of using a seismic survey system. The method can include determining a borehole depth based on at least one soil condition of a location of at least one borehole. Drilling the borehole to the determined borehole depth. Providing location of detonation at least one portable device configured to retain and detonate a blasting cartridge. Detonating the blasting cartridge inside the borehole. Detecting detonation of the blasting cartridge using a detonation sensor. Communicating a signal from the detonation sensor to an event marking device. Triggering by receipt of the signal a recordation by the event marking device of a detonation time and a geographic location of the portable device. 
     In some embodiments of the present technology, the seismic wave can be created by detonating a blasting cartridge retained in the portable device, wherein the sensor is a detonation sensor configured to detect a detonation condition of the blasting cartridge, wherein the signal is a detonation signal, and wherein the time associate with the creation of the seismic wave is a detonation time of the blasting cartridge. 
     In some embodiments, the event marking device can be in communication with a recording system, the event marking device can be configured to communicate at least the detonation time and the geographic location to the recording system. 
     Some embodiments of the present technology can include at least one seismometer configured to detect a seismic condition created by detonation of the blasting cartridge, and to generate a seismic signal including information associated with the seismic condition. 
     In some embodiments, the seismometer can be configured to communicate the seismic signal to the event marking device or a recording system, with the seismic signal including at least a seismic reception time. 
     In some embodiments, the seismometer can include a global positioning unit, the seismometer is configured to communicate geographic location information of the seismometer to the event marking device or the recording system. 
     In some embodiments, the seismometer can be a plurality of seismometers positioned at locations in or on a surface of a geographic area. 
     Some embodiments of the present technology can include a soil sensing device associated with the portable device. The soil sensing device can be configured to sense a condition selected from the group consisting of soil moisture, photosynthetically active radiation (PAR) at soil surface, soil temperature, soil respiration, soil heat flux, solar radiation, gas detection, radiation, PH level, and geochemical measurements. 
     In some embodiments, the detonation sensor can be configured to communicate the detonation signal to the event marking device wirelessly or by way of wiring. 
     In some embodiments, the portable device can include a global positioning unit that is configured to provide geographic location information to the event marking device. 
     Some embodiments of the present technology can include a location antenna attachable to an upper assembly of the portable device. 
     In some embodiments, the seismic wave is created by detonating a blasting cartridge retained in the portable device. The sensor is a detonation sensor configured to detect a detonation condition of the blasting cartridge. The signal is a detonation signal, and the time associate with the creation of the seismic wave is a detonation time of the blasting cartridge. 
     In some embodiments, the blasting cartridge can be detonated at a depth below a surface of the earth. 
     In some embodiments, the depth can be based on at least one soil condition of a location of detonation. 
     Some embodiments of the present technology can include the step of detecting the seismic wave or a reflection of the seismic wave by one or more seismometers, and generating by the seismometers a reception time. 
     Some embodiments of the present technology can include the step of communicating to a recording system the detonation time from the event marking device, and the reception time from the seismometers. 
     Some embodiments of the present technology can include the step of processing by the recording system at least the detonation time and the reception time to provide geological formation information. 
     Some embodiments of the present technology can include the step of communicating to the recording system geographic location information of the portable device and the seismometers, and processing the geographic location information for utilization in providing the geological formation information. 
     There are, of course, additional features of the present technology that will be described hereinafter and which will form the subject matter of the claims attached. 
     Numerous objects, features and advantages of the present technology will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of the present technology, but nonetheless illustrative, embodiments of the present technology when taken in conjunction with the accompanying drawings. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present technology. It is, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present technology. 
     It is therefore an object of the present technology to provide a new and novel portable seismic survey system and method that has all the advantages of the prior art seismic source systems and none of the disadvantages. 
     It is another object of the present technology to provide a new and novel portable seismic survey system and method that may be easily and efficiently manufactured and marketed. 
     An even further object of the present technology is to provide a new and novel portable seismic survey system and method that has a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such portable seismic survey system and method economically available to the buying public. 
     Still another object of the present technology is to provide a portable seismic survey system and method for reflection seismology for mapping subterranean formations. This allows for the portability of the seismic survey device that controls and triggers the event marking device at the time of detonation. 
     Lastly, it is an object of the present technology to provide a new and novel method of using a seismic survey device including the steps of drilling at least one borehole into the ground to be surveyed, and providing at least one portable seismic survey device. Then inserting a lower assembly of the portable seismic survey device into the borehole. Then further, communicating a detonation sensor of the portable seismic survey device with at least one event marking device. After which, detonating a blasting cartridge inside the borehole using the portable seismic survey device, and detecting detonation of the blasting cartridge using a detonation sensor associated with the portable seismic survey device. Then transmitting a signal from the detonation sensor to the event marking device to trigger a recordation of a detonation time and geographic location of the seismic survey device. 
     These together with other objects of the present technology, along with the various features of novelty that characterize the present technology, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the present technology, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated embodiments of the present technology. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present technology will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
         FIG. 1  is a perspective view of an embodiment of the portable seismic survey system and method constructed in accordance with the principles of the present technology, with the phantom lines depicting environmental structure and forming no part of the claimed present technology. 
         FIG. 2  is a perspective view of the portable seismic survey device of the present technology. 
         FIG. 3  is an exploded perspective view of the upper assembly of the present technology. 
         FIG. 4  is an exploded perspective view of the firing weight and piezo holder assembly of the present technology. 
         FIG. 5  is a cross-sectional view of the upper assembly taken along line  5 - 5  in  FIG. 2 . 
         FIG. 6  is an exploded perspective view of the foot support assembly of the present technology. 
         FIG. 7  is a cross-sectional view of the foot support assembly taken along line  7 - 7  in  FIG. 2 . 
         FIG. 8  is an exploded perspective view of the lower assembly, the firing pin guide, the firing pin, the firing chamber and the shot holder of the present technology. 
         FIG. 9  is a cross-sectional view of the firing chamber of the present technology. 
         FIG. 10  is a cross-sectional view of the shot holder with an exploded cartridge of the present technology. 
         FIG. 11  is a cross-sectional view of the lower assembly taken along line  11 - 11  in  FIG. 2 . 
         FIG. 12  is a front plane view of the shot holder tool of the present technology. 
     
    
    
     The same reference numerals refer to the same parts throughout the various figures. 
     DETAILED DESCRIPTION OF THE PRESENT TECHNOLOGY 
     Referring now to the drawings, and particularly to  FIGS. 1-12 , an embodiment of the portable seismic survey system and method of the present technology is shown and generally designated by the reference numeral  10 . 
     In  FIG. 1 , a new and novel portable seismic survey system and method  10  of the present technology for reflection seismology intended for mapping subterranean formations is illustrated and will be described. To collect seismic survey data in a field  2  to be surveyed, a plurality (tens, hundreds or thousands) of ground seismometers  4  can be positioned at predetermined locations in or on the field  2 . The most commonly used seismometer  4  can be a small, portable single component geophone that is planted into the earth and which converts vertical ground motion into a small analog electrical signal. Of late, such sensors have been manufactured with GPS receivers locally coupled to the sensor as well as a battery and sufficient memory to record the signals detected by each sensor continuously for a period of several weeks. It can be appreciated that more sensitive digital sensing units that sense ground motion in three dimensions can be used with the present technology thereby providing better seismic data and new opportunities for sub-surface imaging. 
     Ground motion can then be created with small explosive charges positioned inside a borehole  3  drilled into the surface of the earth at a variable angle and/or a depth that can be variably determined based on local conditions using a portable seismic source device  12 . The angle of the borehole  3  can be configured to facilitate generation of shear waves. The timing and position of these seismic sources should be very accurate, timed to the fraction of a millisecond, with positions accuracies ranging from with 5 metres to less than a metre depending on the geophysical acquisition objectives. 
     As the seismic waves of ground motion created by the seismic source device  12  travels through the earth, they reflect and refract off subsurface geological layers. At the boundary between each geological layer, some energy will be reflected and the rest of the energy will continue through the boundary. As these reflected and refracted signals are detected by the seismometers  4  at the surface, they are either recorded locally into the digital memory coupled to the sensor or they are transmitted either via cable or wireless transmission to a central recording system (not shown) that records all of the reflected ground motion detected by all of the seismometers  4  at the surface. 
     By processing these data, a highly detailed image of subsurface layers of the field  2  can be created. This enables geophysicists, geologists and engineers to interpret and understand the subsurface layers with advantages over other imaging technology. 
     More particularly, the seismic source device  12  can be in communication with a GPS event marking device  5  that is in communication with a GPS or location antenna  6  that can be mounted to a threaded stud  18  at the top of seismic source device  12 . The GPS event marking device  5  can be, but not limited to, a Leica GS25 GNSS instrument or similar device, that can be portable and/or worn on a backpack. The GPS event marking device  5  can be in communication with the central recording system in real time or event data can be uploaded to the central recording system at a later time. 
     As best illustrated in  FIG. 2 , the seismic source device  12  can include an upper assembly  14 , a sensor holding assembly  40 , a main tube  60 , a foot support assembly  76  and a lower tube  80 . The lower tube  80  can have a ground insertion portion with an end including a firing chamber  100  and a cartridge holder  130 . It can be appreciated that the firing chamber  100  and cartridge holder  130  may be attached directly to the main tube  60 , without the use of the lower tube  80 . It can also be appreciated that the length of main tube  60  and lower tube  80  as well as the position and diameter of foot support assembly  76  can be varied to account for different desired hole depths and local conditions. 
     Referring to  FIG. 3 , the upper assembly  14  can include a tubular housing  15  defining a hollow interior or internal cavity, and featuring a first end  16  closed off with an attachable end cap  17  and the threaded stud  18 , and a second end  24 . The threaded stud  18  can be threadably engageable with the end cap  17 , with an end of the threaded stud  18  being receivable in the hollow interior. The threaded stud  18  can include a hook end for hanging the seismic source device  12  or additional peripheral devices can be threadably attached to the threaded stud  18 . The threaded stud  18  can further include a quick release mechanism for fitting the peripheral system and/or the GPS antenna  6  thereto. A jam nut and lock washer can be threadably engaged with the threaded stud  18  to more securely attach the threaded stud  18  in position and prevent rotation thereof. 
     A pair of guide slots  20  can be defined through the tubular housing  15  opposite each other, with the guide slots  20  being in communication with the hollow interior. The guide slots  20  can include a longitudinal slot  21  substantially parallel with a longitudinal axis of the upper assembly  14 , and a lateral slot  22 . 
     The second end  24  can be annularly notched or recessed to define a diameter greater than the hollow interior thereby creating an upper assembly ledge  26 . The second end  24  can include internal threading or other engagement means. 
     The main tube  60  defines a hollow interior capable of freely receiving a firing pin  70  therethrough, and a flanged first end  62 . The flanged first end  62  has a configuration capable of being received in the second end  24  and capable of abutting against the upper assembly ledge  26  when fully assembled. The flanged first end  62  can further include external threading or engagement means capable of engaging with the internal threading of the second end  24 , thereby connecting the upper assembly  14  and the main tube  60  together. 
     Referring to  FIG. 4 , a firing pin actuator  30  can be a firing weight that can have a configuration capable of being slidably receivable in the hollow interior of the upper assembly  14 . The firing weight  30  can include a bore  32  defined parallel with a longitudinal axis of the firing weight  30  which is capable of receiving a first end portion of the firing pin  70 . The firing weight  30  can further include a pair of handle bores  34  opposite each other and lateral to the bore  32 , and an extended end portion  36 . The extended end portion  36  can feature tapered sides. 
     It can be appreciated that the firing pin actuator  30  can be in the alternative, but not limited to, a biasing element, a linear drive means or a rotary drive means, which is capable of advancing and/or retracting the firing pin  70 . 
     The portion of the firing pin  70  received in the bore  32  is secured in place by at least one set screw  39  threadably engaged with at least one set screw bore  38  defined laterally and in communication with the bore  32 . The set screw  39  is capable of contacting an external surface of the firing pin  70  thereby securing the firing pin  70  and the firing weight  30  together. The firing pin  70  can be pitted for nesting of the set screw  39 , or a hole can be defined through the firing pin  70  to receive the set screw  39 , or even still the firing pin  70  can be textured to create a gripping force with the set screw  39  and/or the surface of the actuator  30  that defines the bore  32 . 
     A first actuator handle  42  includes a threaded end  44  capable of engaging with one of the handle bores  34 , wherein the threaded end  44  can have a configuration capable of being slidably received through one of the guide slots  20 . 
     The sensor holding assembly  40  can include a second actuator handle  46  featuring a threaded end  48  capable of engaging with the other of the handle bores  34 , wherein the threaded end  48  can have a configuration capable of being slidably received through the other of the guide slots  20 . The second actuator handle  46  can include a recess with a configuration capable of receiving at least a first end portion of a detonation sensor  54 . At least one set screw can be threadably engageable with a set screw bore  49  defined laterally through the second actuator handle  46  so as to secure the first end portion of the detonation sensor  54  to the second actuator handle  46 . It can be appreciated that the first actuator handle  42  and second first actuator handle  46  are identical, thereby simplifying manufacturing and assembly. 
     Alternatively, a sensor holder  50  can be used for additional securement of the detonation sensor  54 . The sensor holder  50  can include a tubular housing featuring a hollow interior, and a wiring slot  52  parallel with a longitudinal axis of the sensor holder  50 . The hollow interior of the sensor holder  50  can have a configuration capable of receiving a second end portion of the detonation sensor  54 , with wiring  56  of the detonation sensor  54  being passed and slidably received through wiring slot  52 . At least one set screw can be threadably engageable with a set screw bore  53  defined laterally through the sensor holder  50  so as to secure the second end portion of the detonation sensor  54  to the sensor holder  50 . 
     The detonation sensor  54  can be any sensing device that is capable of sensing an operational condition of the seismic source device  12 . The detonation sensor  54  can be, but not limited to, a piezoelectric sensor that uses the piezoelectric effect to measure changes in pressure, acceleration, temperature, strain, or force by converting them to an electrical signal. The detonation sensor  54  can also be, alone or in combination, an acoustical sensor, an impact sensor, a thermal sensor, electrical contact switch (coupled with a battery) and the like. This electrical signal can then be communicated to the GPS event marking device  5  via the wiring  56  or wirelessly. The detonation sensor  54  is configured to detect an operational condition of the seismic source device  12 , so as to trigger an event marking with the GPS event marking device  5 . 
     A switch  58  can be associated with the wiring  56  to control voltage or signal transmission from the detonation sensor  54  to the GPS event marking device  5 . Interrupting voltage or signal transmission from the detonation sensor  54  can avoid unintentional recording and/or event marking by the GPS event marking device  5 . It can be appreciated that switch  58  could be augmented with or replaced by with an electronic device capable of eliminating spurious electrical impulses originating from detonation sensor  54 . Such a device could also record characteristics of those electrical impulses such as the voltage level, timing of the rise or fall in voltage, and so forth. 
     As best illustrated in  FIG. 5 , the flanged first end  62  of the main tube  60  can include an internally defined annular recess  64  capable of receiving an end portion of the firing weight  30  so that at least the extended end portion  36  of the firing weight  30  is receivable in the hollow interior of the main tube  60 . The recess  64  has a diameter greater than the diameter of the main tube hollow interior, thereby creating an annular ledge lateral to the main tube hollow interior. 
     Thus it can be appreciated that the detonation sensor  54  can be secured to the second actuator handle  46  and the piezo holder  50  exterior of the upper assembly  14 , with the second actuator handle  46  being securable to the firing weight  30  located in the hollow interior of the upper assembly  14 . Longitudinal movement of the firing weight  30  and firing pin  70  are dependent upon the location of the first and second actuator handle  42 ,  46  in relation with the guide slots  20 , respectively. Specifically, the firing weight  30  and the firing pin  70  can move in a direction parallel with the longitudinal axis of the upper assembly  14  only when the threaded ends  44 ,  48  of the first and second actuator handles  42 ,  46  are in the longitudinal slot  21  of the guide slots  20 , respectively. Further movement of the firing weight  30  is prohibited when the firing weight  30  contacts the annular ledge that defines the recess  64 . 
     It can be appreciated that the length of the longitudinal slot  21  and/or the distance of the annular ledge defining the recess  64  from the lateral slot  22  determines the travel distance of the firing weight  30  and firing pin  70 . 
     The lateral slot  22  of the guide slots  20  illustrated in  FIG. 3  may contain other features that are also within the scope of the present technology. For example, one feature of the present technology is a safety slot (not shown) that extends from the lateral slot  22  in a direction parallel with the longitudinal slot  21 . The safety slot can receive the threaded ends  44 ,  48  of the first and second actuator handles  42 ,  46  in a locked position thereby preventing accidental movement into the longitudinal slot  21  and preventing unwanted dropping of the firing weight  30  and firing pin  70 . Additionally, locking features can be implemented with the guide slot  20  and/or at least one of the actuator handles  42 ,  46  to prevent unwanted dropping of the firing weight  30  and firing pin  70 . 
     A pair of handles  74  can be attachable to the main tube  60  by way of a clamping bracket. The clamping bracket of each of the handles  74  can be coupled together via fasteners or quick release mechanism to produce a clamping force against the main tube  60 . It can be appreciated that the handles  74  can be adjustably secured along the main tube  60  at any desired location and/or orientation. 
     Referring to  FIG. 6 , the foot support assembly  76  can include a pair of semicircular plates each defined a bore  77  capable of receiving the main tube  60  therethrough. Each plate  76  is securable to a foot plate support  78 . Each foot plate support  78  can include a foot support clamping bracket, which can be coupled together via fasteners or quick release mechanism to produce a clamping force against the main tube  60 . It can be appreciated that the foot support assembly  76  can be adjustably secured along the main tube  60  at any desired location and/or orientation. 
     Turning to  FIG. 7 , the main tube  60  can include a second end  66  featuring an internally defined annular recess capable of engageably receiving a first end  82  of the lower tube  80 . The lower tube  80  includes a hollow interior capable of freely receiving the firing pin  70  therethrough. It can be appreciated that the second end  66  of the main tube  60  and the first end  82  of the lower tube  80  can be configured so as to form a flush interior and/or exterior connection between the main tube  60  and the lower tube  80 . 
     The lower tube  80  can include a plurality of channels  84  defined in an external surface thereof, as best illustrated in  FIGS. 1, 2 and 12 . The channels  84  prevent a vacuum from being created when inserting and/or removing the lower tube  80  in/from the ground. It can be appreciated that the lower tube  80  can include one or more soil sensing devices such as to sense, but not limited to, soil moisture, photosynthetically active radiation (PAR) at soil surface, soil temperature, soil respiration, soil heat flux, solar radiation, gas detection, radiation, PH level, geochemical measurements and the like. 
     As generally shown in  FIG. 8 , the lower tube assembly includes the lower tube  80 , a firing chamber  100  attachable to the lower tube  80 , and a cartridge holder  130  attachable to the firing chamber  100 . A blasting cartridge  150  is loadable in an end of the cartridge holder  130 . 
     As best illustrated in  FIGS. 8 and 11 , the lower tube  80  features a second end  86  that can include an internal annular notch or recess with a diameter greater than the hollow interior of lower tube  80  thereby creating a lower tube ledge. The second end  86  can include internal threading or other engagement means. 
     The firing pin  70  is freely received through the hollow interview of the lower tube  80 , so that a firing tip  72  located at a free end of the firing pin  70  is receivable in the firing chamber  100 . At least one firing pin guide  90  can be secured to the firing pin  70  to guide its movement within the main tube  60  and/or the lower tube  80 . The firing pin guide  90  has a configuration capable of being slidably received within the hollow interior of the main tube  60  or the lower tube  80 . A bore  92  is defined through the firing pin guide  90  parallel to its longitudinal axis, with the bore  92  being capable of receiving therethrough a portion of the firing pin  70 . 
     The portion of the firing pin  70  received in the bore  92  is secured in place by at least one set screw  98  threadably engaged with at least one set screw bore  96  defined laterally and in communication with the bore  92 . The set screw  98  is capable of contacting an external surface of the firing pin  70  thereby securing the firing pin  70  and the firing pin guide  90  together. The firing pin  70  can be pitted for nesting of the set screw  98 , or a hole can be defined through the firing pin  70  to receive the set screw  98 , or even still the firing pin  70  can be textured to create a gripping force with the set screw  98  and/or the surface of the firing pin guide  90  that defines the bore  92 . 
     A notch  94  is defined along an external surface of the firing pin guide  90  to accommodate a head or protrusion of the set screw  98 , thereby preventing the head or protrusion of the set screw  98  from contacting the internal surface of the main tube  60  or the lower tube  80 . 
     As best illustrated in  FIGS. 9 and 11 , the firing chamber  100  includes a first end  102  defining a first end bore  104  capable of slidably receiving therethrough the firing tip  72 , and a flanged second end  106 . An external portion of the firing chamber  100  can include external threading or other engagement means capable of engaging with the internal threading of the second end  86  of the lower tube  80  or the second end  66  of the main tube  60 , thereby connecting the lower tube  80  or main tube  60  and the firing chamber  100  together. The first end  102  has a configuration capable of abutting against the ledge created by the recessed second end  86  when fully assembled. 
     It can be appreciated that an external surface of the flange second end  106  can include protrusions and/or detents that are engageable with a tool to rotate the firing chamber  100  thereby assisting in the assembling and/or disassembling thereof. 
     The firing chamber  100  can further define an internal cavity  108  capable of receiving a portion of the cartridge holder  130 , with the internal cavity  108  being in communication with the first end bore  104 . The internal cavity  108  can include an open end cavity  110 , a first transitional cavity portion  112  in communication with the open end cavity  110 , an intermediate cavity  114  in communication with the first transitional cavity portion  112 , a second transitional cavity portion  116  in communication with the intermediate cavity  114 , and a close end cavity  118  in communication with the second transitional cavity portion  116  and the first end bore  104 . 
     The intermediate cavity  114  has a diameter less than a diameter of the open end cavity  110  and/or the close end cavity  118 , with the first and second transitional cavity portions  112 ,  116  having a planar or arcuate profile. 
     A cartridge cap recess  120  can be defined in the firing chamber  100  adjacent to and in communication with the close end cavity  118 . The cartridge cap recess  120  is capable of receiving a primer end  152  of the blasting cartridge  150 . 
     As best illustrated in  FIGS. 10 and 11 , the cartridge holder  130  can include a through bore  132  defined through the cartridge holder  130  parallel with a longitudinal axis thereof. The through bore  132  is capable of receiving a body of the blasting cartridge  150  with a diameter less than a diameter of the primer end  152 , thereby preventing the primer end  152  from passing therethrough. Consequently, the primer end  152  can abut against a first end  134  of the cartridge holder  130 . 
     The cartridge holder  130  can include a flanged portion  136  adjacent the first end  134 , an intermediate portion  138  adjacent the flanged portion  136 , a transitional portion  140  adjacent the intermediate portion  138 , a guide portion  142  adjacent the transitional portion  140 , and a flanged end  144  adjacent the guide portion  142 . 
     The first end  134  is capable of traveling through the open end cavity  110  and the intermediate cavity  114  so as to be receivable in the close end cavity  118  of the firing chamber  100  when assembled. The intermediate portion  138  is capable of traveling through the open end cavity  110 , and can include external threading or other engagement means engageable with internal threading of the intermediate cavity  114  of the firing chamber  100 . The guide portion  142  is capable of being receivable in the open end cavity  110  of the firing chamber  100 . 
     The flanged end  144  can include radial notches  146  that are engageable with teeth  156  of a tool  154  ( FIG. 12 ) such as, but not limited to, a wrench, a socket, pliers and the like. The tool  154  is capable of rotating the cartridge holder  130  thereby assisting in the assembling and/or disassembling thereof. 
     As best illustrated in  FIG. 11 , the blasting cartridge  150  is received in the bore  132  of the cartridge holder  130  so that the primer end  152  abuts the first end  134 . The first end  134  of the cartridge holder  130  is received in the internal cavity  108  of the firing chamber  100  so that the cartridge holder  130  is joined to the firing chamber  100 . The first end  102  of the firing chamber  100 , with the assembled cartridge holder  130 , is then received in the second end  86  of the lower tube  80 . 
     When assembled, the firing pin  70  can reciprocally move within the hollow interior of the lower tube  80  while being guided by the firing pin guide  90  attached to the firing pin  70 . The firing tip  72  can reciprocally move within the first end bore  104  so as to impact the primer end  152  of the blasting cartridge  150 . 
     In use, it can now be understood that at least one borehole  3  is drilled below the surface of the earth  2 . Ground seismometers  4  are positioned at predetermined locations in or on the field  2  at locations associated with the borehole  3 . The present technology can be used, but not limited to, oil and gas exploration, geotechnical work associated with engineering bridges, pipelines, roadways, tunnels and the like. Imaging of caprock and the underlying reservoir(s) associated with SAGD production is also envisioned for possible uses of the present technology. 
     A user would insert the blasting cartridge  150  into the bore  132  of the cartridge holder  130  with its primer end  152  abutting the first end  134  of the cartridge holder  130 . The cartridge holder  130  can then be coupled to the firing chamber  100 . The tool  154  can be used to assist in engaging the cartridge holder  130  with the firing chamber  100 . 
     For safety, the user would position and retain the threaded ends  44 ,  48  of the first and second actuator handles  42 ,  46  in their respective lateral slot  22  so that the firing weight  30  and firing pin  70  are in a non-operable position. The detonation sensor  54  is secured to the second actuator handle  46  and the piezo holder  50 . 
     While in this non-operable position, the firing chamber  100  and the assemble cartridge holder  130  can then be coupled to the second end  86  of the lower tube  80 , with the firing tip  72  adjacent or received in the first end bore  104  of the firing chamber  100 . The tool  154  can be used to assist in engaging the assembled firing chamber  100  and cartridge holder  130  with the lower tube  80  or the main tube  60 . 
     The seismic source device  12  can then be inserted into the borehole  3  so that it is in a substantially vertical orientation. The user can then stand on the foot support assembly  76 , and can grasp as least one of the handles  74 . 
     When ready, the user can operate the switch  58  to allow communication from the detonation sensor  54  to the GPS event marking device  5 , and then move the first actuator handle  42  and/or second actuator handle  46  so that their threaded ends  44 ,  48  are moved out of their respective lateral slot  22  and into their respective longitudinal slot  21 . In this operable position, the threaded ends  44 ,  48  of the first and second actuator handles  42 ,  46  are free to drop or travel along the longitudinal slot, due to gravity and the weight of the firing weight  30  or any other driving force. 
     As the firing weight  30  drops it simultaneously moves the firing pin  70  toward the firing chamber  100  until the firing tip  72  strikes the primer end  152  of the blasting cartridge  150 , thereby detonating the blasting cartridge  150  inside the borehole  3 . Upon contact, the blasting cartridge  150  is detonated thereby creating a seismic wave that propagates from inside the borehole  3  and through the earth until it is reflected and refracted off of subsurface geological layers in the field  2 . 
     The detonation sensor  54  detects the detonation of the blasting cartridge  150  and generates a voltage or signal to the GPS event marking device  5 . The GPS event marking device  5  is then triggered by this signal from the detonation sensor  54  to record the precise time (T=0) and geographical location of detonation. Detonation time (T=0) can be recorded with sub-millisecond accuracy. It can be appreciated that the detonation sensor  54  triggers and controls the operation of the GPS event marking device  5 , and not the GPS event marking device  5  controlling the time of detonation. It can be appreciated that blasting cartridge  150  can be engineered with a delay, in which case the known delay can be added to the detonation time signaled by the detonation sensor  54  to provide a more accurate adjusted detonation time (T=0). 
     The reflected and refracted waves travel back toward the ground seismometers  4 , which may also be equipped with GPS units that record reception time and/or geographical location. Detonation time from the GPS event marking device  5  and reception times from the seismometers  4  can be communicated, along with geographical locations, to the central recording system to be correlated. The central recording system can then process detonation time and location, and reception times and locations, to provide geological formation information. 
     Alternatively, the second end  66  of the main tube  60  and the first end  82  of the lower tube  80  can be associated with a bearing, and a drive means can be coupled to the lower tube  80  so as to rotate the lower tube  80  in relation to the main tube  60 . The lower tube  80  or the cartridge holder  130  can further include a drilling bit or teeth means that is capable of drilling into the ground. Thus combining a drilling means with the lower assembly. 
     It can further be appreciated that the lower assembly can include an automatic blasting cartridge loading means, which is capable of removing a spent blasting cartridge and loading a new blasting cartridge for subsequent use. The seismic source device  12  can further include a holding device capable of holding one or more blasting cartridges  150 . The firing pin  70  can have a configuration capable of simultaneously detonating several blasting cartridges  150 , some of which would have different orientations (vertical, lateral, etc.). 
     Still further, it can be appreciated that the seismic source device  12  can include a spirit (bubble) level or an electronic level having a configuration capable of indicating an angle of the device  12  relative to the earth&#39;s nadir. 
     Even still further, it can be appreciated that all the above described threading engagements can be replaced with any mechanical engagement means such as, but not limited to, ratchets, clips, clasps, magnetics, tabs, keys, wedges, press fit surfaces, adhesives, welding and the like. Additionally, any or all transitional edges can be chamfered or beveled. 
     While embodiments of the portable seismic survey system and method have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the present technology. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the present technology, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present technology. For example, any suitable sturdy material may be used. 
     Therefore, the foregoing is considered as illustrative only of the principles of the present technology. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the present technology to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the present technology.